JP4470537B2 - High frequency receiver, integrated circuit used therefor, and television broadcast receiver using the same - Google Patents

Description

  The present invention relates to a high-frequency receiving device used for a television, a DVD, and the like and an integrated circuit thereof.

  Hereinafter, a conventional high-frequency receiving device will be described with reference to the drawings. FIG. 6 is a block diagram of a conventional high frequency receiver.

  In FIG. 6, 1 is an input terminal. A high frequency signal from 55.25 MHz to 801.25 MHz is input to the input terminal 1. Reference numeral 2 denotes a single-tuned filter that is supplied with a high-frequency signal inputted to the input terminal 1 and is composed of one variable capacitance diode. The tuning frequency of the single tuning filter 2 is in the UHF broadcast band (367.25 MHz to 801.25 MHz), and the tuning frequency is changed using the tuning voltage supplied to the frequency variable terminal 2a. .

  Reference numeral 3 denotes a high-frequency amplifier to which the output of the single tuning filter 2 is connected, and amplifies a signal in this UHF broadcast band. Reference numeral 4 denotes a double-tuned filter to which the output of the high-frequency amplifier 3 is connected. This double-tuned filter 4 is composed of two variable-capacitance diodes, and changes the tuning frequency using the tuning voltage supplied to the frequency variable terminal 4a.

  Reference numeral 5 denotes a mixer. The output signal of the double-tuned filter 4 is input to one of the mixers, and the output signal of the local oscillator 6 is input to the other side via the frequency divider 7. This mixer 5 mixes the UHF broadcast band signal that has passed through the double-tuned filter 4 and the oscillation signal of the local oscillator 6 and converts them to an intermediate frequency signal of 45.75 MHz. Reference numeral 8 denotes an intermediate frequency filter to which the output of the mixer 5 is connected, which attenuates unnecessary signals in an occupied band of 6 MHz. Reference numeral 9 denotes an output terminal to which an output signal of the intermediate frequency filter 8 is supplied via an intermediate frequency amplifier.

  The single tuning filter 2, the high frequency amplifier 3, the double tuning filter 4, the mixer 5 and the intermediate frequency filter 8 constitute a UHF signal receiver 10.

  Next, 11 is a VHF signal receiver to which the signal of the input terminal 1 is supplied. The VHF signal receiver 11 receives a VHF broadcast band signal from 55.25 MHz to 361.25 MHz, and includes a single tuning filter 12, a high frequency amplifier 13, a double tuning filter 14, and a mixer 15. ing.

  First, reference numeral 12 denotes a single tuning filter composed of one variable capacitance diode, which changes the tuning frequency using a tuning voltage supplied to the frequency variable terminal 12a. Reference numeral 13 denotes a high-frequency amplifier to which the output of the single tuning filter 12 is connected, which amplifies a signal in the VHF broadcast band.

  Reference numeral 14 denotes a double-tuned filter to which the output of the high-frequency amplifier 13 is connected. The double-tuned filter 14 is composed of two variable capacitance diodes, and changes the tuning frequency using a tuning voltage supplied to the frequency variable terminal 14a. Reference numeral 15 denotes a mixer. The output signal of the double-tuned filter 14 is input to one of the mixers, and the output signal of the local oscillator 6 is input to the other side via the frequency divider 16. The mixer 15 mixes the signal of the VHF broadcast band that has passed through the double-tuned filter 14 and the oscillation signal of the local oscillator 6 and converts it to an intermediate frequency signal of 45.75 MHz. The output of the mixer 15 is connected to the input of the intermediate frequency filter 8.

  Next, reference numeral 17 denotes an oscillating unit, and a tuning unit 18 is connected to the inputs 17 a and 17 b of the oscillating unit 17. The tuning unit 18 includes a series connection body 21 of a variable capacitance diode 19 and a capacitor 20 and an inductor 22 connected in parallel with the series connection body 21.

  Reference numeral 23 denotes a PLL circuit, and the output of the oscillation unit 17 is connected to the input of the PLL circuit 23. The tuning voltage output from the output terminal 23a of the PLL circuit 23 includes the variable capacitance diode 19 of the tuning unit 18 and the variable capacitance diodes of the single tuning filter 2, the double tuning filter 4, the single tuning filter 12, and the double tuning filter 14. To be supplied.

  Next, the operation of the local oscillator 6 and the frequency dividers 7 and 16 in the conventional high frequency receiving apparatus will be described with reference to FIG. FIG. 7 is a characteristic diagram of the local oscillator. The horizontal axis 31 is the frequency (MHz) applied to the mixer 5 or 15, and the vertical axis 32 is the output voltage (V) of the PLL circuit 23.

  In FIG. 7, 33 is a characteristic of the local oscillation signal supplied to the mixer 5 of the UHF signal receiver 10 (hereinafter referred to as a mixer input at the time of UHF reception). When receiving a signal in the UHF broadcast band, an oscillation signal having an output tuning voltage of about 350 MHz when the PLL circuit 23 is 1 V and an oscillation signal of about 850 MHz when the tuning voltage is 24 V is obtained.

  Reference numeral 34 denotes a conventional high-frequency receiving apparatus that divides the output of the local oscillator 6 as it is by the frequency divider 16, and is a characteristic of the local oscillation signal supplied to the mixer 15 when receiving a signal in the VHF high-band broadcasting band. Is a characteristic of a local oscillation signal suitable for receiving a signal in the VHF high-band broadcasting band.

  Reference numeral 36 denotes a conventional high-frequency receiving apparatus that divides the output of the local oscillator 6 as it is by the frequency divider 16, and is a characteristic of a local oscillation signal supplied to the mixer 15 when a signal in the VHF low-band broadcast band is received, and 37 is VHF. This is a characteristic of a local oscillation signal suitable for receiving a signal in a low-band broadcast band.

For example, Patent Document 1, Patent Document 2, and Patent Document 3 are known as prior art document information related to the invention of this application.
JP 2000-295539 A JP 2002-118795 A JP-A-1-265688

  However, such a conventional high-frequency receiving device has a problem that a frequency range that cannot oscillate in the tuning voltage variable range is generated and cannot be received. That is, as shown in FIG. 7, the local oscillation signal characteristic as originally indicated by 35 is necessary, but when the local oscillation signal as indicated by 33 is divided by the frequency divider 16 as it is, the mixer 15 There is a problem that a waveform that can not be oscillated in the variable range of the tuning voltage, such as 34, is generated in the waveform supplied to.

  Therefore, the present invention has been made to solve this problem, and an object of the present invention is to provide a high-frequency receiving apparatus that can receive a wideband channel of a continuous VHF broadcast band and a UHF broadcast band.

In order to achieve this object, the local oscillator in the high-frequency receiving device of the present invention includes an oscillation unit, a tuning unit connected to the input of the oscillation unit, and an oscillation frequency inserted between the tuning unit and the oscillation unit. The tuning unit includes a series connection body of an oscillation variable capacitance diode and a first capacitor, and an inductor connected in parallel to the series connection body, the first variable capacitance diode and the the second variable capacitance diode and a substantially equal capacitance change characteristic value of the required capacitance change ratio with respect to the frequency bandwidth required the largest capacitance change ratio of the frequency band to be received and the oscillation variable capacity diode The PLL circuit supplies a tuning voltage to the first variable capacitance diode, the second variable capacitance diode, and the oscillation variable capacitance diode; The number changing means includes a third variable capacitance diode connected in parallel with the oscillation variable capacitance diode, and a first variable capacitance diode inserted between the cathode terminal of the third variable capacitance diode and the oscillation variable capacitance diode. 2 capacitor, a fourth variable capacitance diode connected in parallel with the first capacitor, and a third variable capacitor inserted between the cathode terminal of the fourth variable capacitance diode and the first capacitor. A capacitor, and a control circuit connected between each of the cathode terminals of the third and fourth variable capacitance diodes and the PLL circuit, the control circuit according to the frequency band to be received. When the voltage supplied to the fourth variable capacitance diode is changed and the first frequency band is received, the frequency characteristics of the first tuning filter are linked. Moni, when receiving the second frequency band, in conjunction with the frequency characteristic of the second tuning filter, but only get different oscillation signals a predetermined frequency.

Thus, the station oscillator provided an oscillation frequency changing means, in conjunction with the frequency characteristic of the first tuning filter when the oscillation frequency changing means receives the first frequency band the frequency of the oscillation signal, the when receiving the second frequency band than Ru varied to work in the frequency characteristic of the second tuning filter, it is possible to widen the range of the oscillation frequency of the local oscillator with respect to the tuning voltage, even if the first Even if the channel between the frequency band and the second frequency band is continuous, reception is possible. Therefore, for example, in TV broadcasting, it is possible to receive a continuous wide band of VHF broadcasting band and UHF broadcasting band.

  Moreover, since a variable capacitance diode is used for the oscillation frequency changing means, it can be set to a predetermined capacitance value according to the voltage supplied to the cathode side terminal. Therefore, the oscillation frequency can be easily set by the oscillation frequency changing means.

Further, since the control circuit changes the capacitance value of the third variable capacitance diode connected in parallel with the oscillation variable capacitance diode, the oscillation characteristics of the local oscillator at a high oscillation frequency can be controlled.

Furthermore, since the control circuit changes the voltage supplied to the fourth variable capacitance diode provided in parallel with the first capacitor, the tuning voltage can be changed by appropriately changing the capacitance value of the fourth variable capacitance diode. It is possible to control the width of the capacitance change with respect to the change width.

In addition, the capacitance change ratio values of the first variable capacitance diode, the second variable capacitance diode, and the oscillation variable capacitance diode require the largest capacitance change ratio in the received frequency band. Having substantially equal to the value of the required capacitance change ratio with respect to frequency bands, it is possible to approximate the frequency characteristic of the oscillation frequency of the tuning unit and the frequency characteristic of the tuning filter. Therefore, the frequency characteristic of the tuning filter and the frequency characteristic of the local oscillator can be linked to each other, and a wide frequency band can be received, even if the first frequency band and the second frequency band are continuous. Therefore, it is possible to realize a high-frequency receiving device that can also receive the signal.

In addition, since variable capacitance diodes having substantially the same capacitance change ratio are used, the variable capacitance diodes used for the tuning filter and the oscillation variable capacitance diodes may be of the same product number, so that the management becomes easy. Furthermore, since the variable capacitance diodes used in the high frequency receiver can be unified, mounting errors are also reduced.

Furthermore, since the capacity change range can be increased, signals in a wide frequency band can be received.

The invention according to claim 2 is the high-frequency receiving device according to claim 1, wherein the fourth variable capacitance diode is provided in series with the inductor, and the same is achieved by varying the capacitance of the fourth variable capacitance diode. A wider frequency band can be oscillated within the tuning voltage variable range.

According to a third aspect of the present invention, there is provided a high frequency receiving apparatus for receiving a high frequency signal by dividing the high frequency signal into at least a first frequency band and a second frequency band lower than the first frequency band. The high-frequency receiving apparatus is supplied with an input terminal, a signal input to the input terminal, and a tuning filter whose tuning frequency is changed by a change in capacitance of the first variable capacitance diode, and an output of the tuning filter is one of them. And a mixer for converting a first signal in the first frequency band to an intermediate frequency, and an output of the mixer. When receiving a supplied output terminal and a second signal within the second frequency band, the local oscillator is adapted to convert the signal within the second frequency band to the intermediate frequency. And a frequency divider provided between the mixer and the mixer, and selectively supplying to the mixer according to a frequency band for receiving either the output of the divider or the output of the local oscillator And a local oscillator, and a PLL circuit that tunes and controls the local oscillator and the tuning filter to a reception channel. The local oscillator includes an oscillation unit, a tuning unit connected to an input of the oscillation unit, and the tuning unit. And an oscillation frequency changing means inserted between the oscillation unit, the tuning unit comprising a series connection body of an oscillation variable capacitance diode and a first capacitor, and an inductor connected in parallel to the series connection body has the door, the required volume variations for the frequency bandwidth required the largest capacitance change ratio of the received frequency band from the first variable capacitance diode and the oscillation variable capacity diode The capacitance change characteristic is approximately equal to the value of the ratio, the PLL circuit supplies a tuning voltage to the first variable capacitance diode and the oscillation variable capacitance diode, and the changeover switch according to the frequency band to be received The oscillation frequency changing means is switched between a second variable capacitance diode connected in parallel with the oscillation variable capacitance diode, a cathode side terminal of the second variable capacitance diode, and the oscillation variable capacitance diode. A second capacitor inserted in between, a third variable capacitance diode connected in parallel with the first capacitor, and a cathode side terminal of the third variable capacitance diode and the first capacitor Between the inserted third capacitor, the cathode side terminals of the second and third variable capacitance diodes, and the PLL circuit. And a control circuit connected to the control circuit, wherein the control circuit changes the voltage supplied to the second and third variable capacitance diodes according to the received frequency band, and adjusts the tuning filter for each frequency band. This is a high-frequency receiving device that obtains an oscillation signal that differs only by a predetermined frequency in conjunction with the frequency characteristics, so that the local oscillator can link the oscillation signal to the frequency characteristics of the tuning filter in accordance with the reception band to be received. Since the oscillation frequency changing means for changing to the tuning voltage is provided, the range of the oscillation frequency of the local oscillator with respect to the tuning voltage can be widened, even if the channel between the first frequency band and the second frequency band is continuous. Even if it is, it can be received. Therefore, in TV broadcasting, it is possible to realize a high-frequency receiving device that can receive a wide-band channel of continuous VHF broadcasting band and UHF broadcasting band.

According to a fourth aspect of the present invention, there is provided a high frequency receiving apparatus for receiving a high frequency signal by dividing the high frequency signal into at least a first frequency band and a second frequency band lower than the first frequency band. The high-frequency receiving apparatus is supplied with an input terminal, a signal input to the input terminal, and a tuning filter whose tuning frequency is changed by a change in capacitance of the first variable capacitance diode, and an output of the tuning filter is one of them. To the other input, and to the other input, a mixer to which the output of the frequency divider whose frequency division ratio is changed according to the received frequency band is connected, and an output to which the output of this mixer is supplied A local oscillator connected to the input of the frequency divider, and a PLL circuit to which the output signal of the frequency divider is supplied. The local oscillator is connected to the oscillation unit and the input of the oscillation unit. And a oscillating frequency changing means inserted between the tuning unit and the oscillating unit, the tuning unit comprising a series connection body of an oscillation variable capacitance diode and a first capacitor, An inductor connected in parallel to a series connection body, wherein the first variable capacitance diode and the oscillation variable capacitance diode are for a frequency band that requires the largest capacitance change ratio in the received frequency band. The PLL circuit is supplied with the output of the local oscillator and supplies a tuning voltage to the first variable capacitance diode and the oscillation variable capacitance diode. And a frequency dividing ratio of the frequency divider is set in accordance with a frequency band to be received, and the oscillation frequency changing means is connected to a second oscillation variable capacitance diode in parallel. A variable capacitance diode, a second capacitor inserted between the cathode side terminal of the second variable capacitance diode and the oscillation variable capacitance diode, and a third variable connected in parallel with the first capacitor A capacitor diode, a third capacitor inserted between the cathode side terminal of the third variable capacitance diode and the first capacitor, and a cathode side terminal of the second and third variable capacitance diodes The control circuit varies the voltage supplied to the second and third variable capacitance diodes according to the frequency band to be received, and is supplied from the PLL circuit in each frequency band to be received. The oscillation frequency characteristic of the local oscillator with respect to the tuning voltage to be changed is changed to a predetermined frequency in conjunction with the frequency characteristic of the tuning filter. This is a high-frequency receiver that obtains different frequency divider outputs.

  As a result, the local oscillator has oscillation frequency changing means for changing the oscillation signal in accordance with the frequency characteristics of the tuning filter in accordance with the reception band to be received. The range can be widened, and even if the channel between the first frequency band and the second frequency band is continuous, it can be received. Therefore, in TV broadcasting, it is possible to realize a high-frequency receiving device that can receive a wide-band channel of continuous VHF broadcasting band and UHF broadcasting band.

Further, since the control circuit changes the third variable capacitance diode provided in parallel with the first capacitor, the capacitance with respect to the change width of the tuning voltage can be changed by appropriately changing the capacitance value of the third variable capacitance diode. The width of change can be controlled.

Further, since the control circuit changes the capacitance value of the third variable capacitance diode connected in parallel with the oscillation variable capacitance diode, the oscillation characteristics of the local oscillator at a high oscillation frequency can be controlled.

In the fifth aspect of the present invention, the frequency divider includes a plurality of frequency dividers, and the plurality of frequency dividers are selectively selected according to a frequency band for receiving a signal input to the mixer. 5. The high-frequency receiving device according to claim 4 , wherein a changeover switch for switching is connected, whereby a frequency division ratio suitable for regions having different frequency bands and reception frequencies can be set, and continuous VHF broadcast bands and UHFs can be set. A broadband channel of the broadcast band can be received.

According to a sixth aspect of the present invention, the frequency divider includes a first fixed frequency divider that divides the output frequency of the local oscillator by 1/2, and an output of the first fixed frequency divider is a common terminal. And a switch that has one output connected to the other terminal of the mixer, and is inserted between the other terminal of the selector switch and the other terminal of the mixer. 5. The high-frequency receiving device according to claim 4 , further comprising a second fixed frequency divider that divides the output signal of the fixed frequency divider by 1/2, thereby fixing the frequency division ratio to 1/2. Since the 1/2 frequency divider can be configured with two frequency dividers, a frequency divider can be realized with a simple circuit configuration.

According to a seventh aspect of the present invention, the tuning filter is provided in parallel with the first tuning filter that tunes to a frequency in the first frequency band, and in the second frequency band. 5. The high-frequency receiving device according to claim 4 , comprising a second tuning filter that tunes to a frequency, and is configured by a two-stage filter to sufficiently suppress interference of an unwanted signal with respect to a desired signal. can do.

The invention according to claim 8, first mixer and the second mixer and a PLL circuit for forming a high-frequency receiver according to claim 1 and the oscillation portion and the divider and control circuit are integrated Therefore, even if the first frequency band and the second frequency band are a continuous wide frequency band, it is possible to receive the integrated circuit. Furthermore, even if this broadcast band is a broadcast band of the VHF broadcast band and the UHF broadcast band, all broadcast channels within those bands can be received. In addition, the high-frequency receiver can be reduced in size.

The invention described in claim 9 is an integrated circuit characterized in that at least the mixer, the PLL circuit, the oscillating unit, and the frequency divider that form the high-frequency receiving device according to claim 3 are integrated. Thus, the local oscillator has oscillation frequency changing means for changing the oscillation signal in accordance with the frequency characteristics of the tuning filter in accordance with the reception band to be received, so that the oscillation frequency of the local oscillator with respect to the tuning voltage can be changed. The range can be widened, and even if the channel between the first frequency band and the second frequency band is continuous, it can be received. Therefore, in TV broadcasting, it is possible to realize a high-frequency receiving device that can receive a wide-band channel of continuous VHF broadcasting band and UHF broadcasting band. In addition, the high-frequency receiver can be reduced in size.

A tenth aspect of the present invention is an integrated circuit in which the mixer, the PLL circuit, the oscillation unit, and the frequency divider that form the high-frequency receiving device according to the fourth aspect are integrated at least. Thus, the local oscillator has oscillation frequency changing means for changing the oscillation signal in accordance with the frequency characteristics of the tuning filter in accordance with the reception band to be received, so that the oscillation frequency of the local oscillator with respect to the tuning voltage can be changed. The range can be widened, and even if the channel between the first frequency band and the second frequency band is continuous, it can be received. Therefore, in TV broadcasting, it is possible to realize a high-frequency receiving device that can receive a wide-band channel of continuous VHF broadcasting band and UHF broadcasting band. In addition, the high-frequency receiver can be reduced in size.

Also, the control circuit, by changing the capacitance value of the third variable capacitance diode connected in parallel with the first capacitor, the capacitance which is inserted between the oscillation variable capacity diode and the oscillation portion changes Will be. Therefore, by changing the value of the third variable capacitance diode as appropriate, it is possible to control the capacitance change width with respect to the tuning voltage change width .

Further, since the control circuit changes the capacitance value of the third variable capacitance diode connected in parallel with the oscillation variable capacitance diode, the oscillation characteristics of the local oscillator at a high oscillation frequency can be controlled .

The eleventh aspect of the present invention is connected to the input of the PLL circuit and the input of the control circuit in the high-frequency receiving device according to the first or fourth aspect , and indicates the desired reception channel by the operation of the operator. A microcomputer to which a channel selection signal is input; and the microcomputer supplies a tuning voltage corresponding to the channel selection signal to the PLL circuit and supplies a voltage corresponding to the channel selection signal to the control circuit. Since the PLL circuit and the control circuit each independently control the first or second tuning filter, the tuning unit, and the third variable capacitance diode based on the signal from the microcomputer. The load for signal processing of the microcomputer can be reduced. Therefore, signal processing can be performed at high speed .

As described above, according to the present invention, the local oscillator includes the oscillation unit, the tuning unit connected to the input of the oscillation unit, and the oscillation frequency changing means inserted between the tuning unit and the oscillation unit. The tuning unit includes a series connection body of an oscillation variable capacitance diode and a first capacitor, and an inductor connected in parallel to the series connection body, and the first variable capacitance diode and the second variable capacitance. a substantially equal capacitance change characteristic value of the required capacitance change ratio with respect to the frequency bandwidth required the largest capacitance change ratio of the frequency band to receive the capacitance diode and the oscillation variable capacity diode, the PLL circuit Supplies a tuning voltage to the first variable capacitance diode, the second variable capacitance diode, and the oscillation variable capacitance diode, and the oscillation frequency changing means includes an oscillation variable A third variable capacitance diode connected in parallel with the quantity diode, a second capacitor inserted between the cathode terminal of the third variable capacitance diode and the oscillation variable capacitance diode, A fourth variable capacitance diode connected in parallel with the capacitor, a third capacitor inserted between the cathode side terminal of the fourth variable capacitance diode and the first capacitor, the third and second And a control circuit connected between the respective cathode side terminals of the four variable capacitance diodes and the PLL circuit. The control circuit is connected to the third and fourth variable capacitance diodes according to the frequency band to be received. When receiving the first frequency band by changing the voltage to be supplied, the second frequency band is linked to the frequency characteristics of the first tuning filter. Is received in synchronization with the frequency characteristics of the second tuning filter, the oscillation signals differing by a predetermined frequency are obtained, so that the range of the oscillation frequency of the local oscillator with respect to the tuning voltage can be widened. Even if the channel between the first frequency band and the second frequency band is continuous, it can be received. Therefore, for example, in TV broadcasting, it is possible to provide a high-frequency receiving apparatus that can receive a wideband channel of a continuous VHF broadcast band and a UHF broadcast band.

  Moreover, since a variable capacitance diode is used for the oscillation frequency changing means, it can be set to a predetermined capacitance value according to the voltage supplied to the cathode side terminal. Therefore, the oscillation frequency can be easily set by the oscillation frequency changing means.

Further, since the control circuit changes the capacitance value of the third variable capacitance diode connected in parallel with the oscillation variable capacitance diode, the oscillation characteristics of the local oscillator at a high oscillation frequency can be controlled.

Furthermore, since the control circuit changes the voltage supplied to the fourth variable capacitance diode provided in parallel with the first capacitor, the tuning voltage can be changed by appropriately changing the capacitance value of the fourth variable capacitance diode. It is possible to control the width of the capacitance change with respect to the change width.

In addition, the capacitance change ratio values of the first variable capacitance diode, the second variable capacitance diode, and the oscillation variable capacitance diode require the largest capacitance change ratio in the received frequency band. Having substantially equal to the value of the required capacitance change ratio with respect to frequency bands, it is possible to approximate the frequency characteristic of the oscillation frequency of the tuning unit and the frequency characteristic of the tuning filter. Therefore, the frequency characteristic of the tuning filter and the frequency characteristic of the local oscillator can be linked to each other, and a wide frequency band can be received, even if the first frequency band and the second frequency band are continuous. Therefore, it is possible to realize a high-frequency receiving device that can also receive the signal.

In addition, since variable capacitance diodes having substantially the same capacitance change ratio are used, the variable capacitance diodes used for the tuning filter and the oscillation variable capacitance diodes may be of the same product number, so that the management becomes easy. Furthermore, since the variable capacitance diodes used in the high frequency receiver can be unified, mounting errors are also reduced.

Furthermore, since the capacity change range can be increased, signals in a wide frequency band can be received.

(Embodiment 1)
Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a main part of a television broadcast receiver using the high-frequency receiver according to the first embodiment.

  In FIG. 1, 51 is an input terminal. The input terminal 51 receives a high frequency signal from 55.25 MHz to 801.25 MHz. Reference numeral 52 denotes a single tuning filter (used as an example of a first tuning filter) which is connected to the input terminal 51 and includes one variable capacitance diode. The tuning frequency of the single tuning filter 52 is to change the tuning frequency using the tuning voltage supplied to the frequency variable terminal 52a in the UHF broadcasting band from 367.25 MHz to 801.25 MHz.

  Reference numeral 53 denotes a high frequency amplifier to which the output of the single tuning filter 52 is connected, and amplifies the UHF broadcast band signal. 54 is a double-tuned filter (used as an example of the second tuned filter) to which the output of the high-frequency amplifier is connected. The double-tuned filter 54 includes two variable capacitance diodes, and changes the tuning frequency using a tuning voltage supplied to the frequency variable terminal 54a.

  Reference numeral 55 denotes a mixer. The output signal of the double-tuned filter 54 is input to one of them, and the output signal of the local oscillator 56 is input to the other side through a frequency divider 57. The mixer 55 mixes the UHF broadcast band signal that has passed through the double-tuned filter 54 and the oscillation signal of the local oscillator 56 and converts them to an intermediate frequency signal of 45.75 MHz.

  Reference numeral 58 denotes an intermediate frequency filter to which the output of the mixer 55 is connected, which attenuates unnecessary signals to an occupied band of 6 MHz. Reference numeral 59 denotes an output terminal to which an output signal of the intermediate frequency filter 58 is supplied via an intermediate frequency amplifier.

  The single tuning filter 52, the high frequency amplifier 53, the double tuning filter 54, the mixer 55, and the intermediate frequency filter 58 constitute a UHF signal receiver 60.

  Next, 61 is a VHF signal receiver to which the signal of the input terminal 51 is supplied, and receives a signal in the VHF broadcast band from 55.25 MHz to 361.25 MHz. In the VHF signal receiver 61, a single tuning filter 62, a high frequency amplifier 63, a double tuning filter 64, and a mixer 65 are connected in this order.

  Reference numeral 62 denotes a single tuning filter including one variable capacitance diode, which changes the tuning frequency using a tuning voltage supplied to the frequency variable terminal 62a. Reference numeral 63 denotes a high frequency amplifier to which the output of the single tuning filter 62 is connected, and amplifies a signal in the VHF broadcast band.

  Reference numeral 64 denotes a double-tuned filter to which the output of the high-frequency amplifier 63 is connected. The double-tuned filter 64 includes two variable capacitance diodes, and changes the tuning frequency using a tuning voltage supplied to the frequency variable terminal 64a.

  Reference numeral 65 denotes a mixer. The output signal of the double-tuned filter 64 is input to one of the mixers, and the output signal of the local oscillator 56 is input to the other side via the frequency divider 66. Here, the mixer 65 mixes the signal of the VHF broadcast band that has passed through the double-tuned filter 64 and the signal of the local oscillator 56 and converts them to an intermediate frequency signal (45.75 MHz). The output of the mixer 65 is connected to the input of the intermediate frequency filter 58.

  Here, the frequency divider 66 includes a frequency divider 66a for receiving the VHF low-band broadcast band and a frequency divider 66b for receiving the VHF high-band broadcast band. These frequency dividers 57, 66a, and 66b are included in the frequency divider 66a. A changeover switch 67 (a, b, c) for switching is connected between the frequency dividers 57 and 66 and the other input of the mixers 55 and 65.

  Next, the local oscillator 56 includes an inductor 68, a tuning unit 72 configured by a series connection body of a variable capacitance diode 69 (used as an example of an oscillation variable capacitance diode) and a capacitor 70 in parallel with the inductor 68, The oscillation unit 71 is connected to both ends of the serial connection body, and the oscillation frequency changing unit 73 is connected between the oscillation unit 71 and the tuning unit 72.

  The oscillation frequency changing means 73 includes a variable capacitance diode 74 used as an example of a third variable capacitance diode connected in parallel with the variable capacitance diode 69, and a third variable capacitance diode connected in parallel with the capacitor 70. The variable capacitance diode 75 used as an example, and the control circuit 76 connected between the cathode side terminals of these variable capacitance diodes and the output of the PLL circuit.

  As a result, the voltage supplied to the variable capacitance diodes 74 and 75 by the control circuit 76 is changed. Therefore, in the first embodiment, by changing the voltage supplied to these variable capacitance diodes 74 and 75 according to the channel to be received, the capacitance value inserted in series in the oscillation variable capacitance diode 69 and Since the capacitance value inserted in parallel with the oscillation variable capacitance diode 69 can be changed, the tuning frequency of the tuning unit can be changed, and the oscillation frequency of the local oscillator can be changed minutely.

  Further, if a variable capacitance diode 77 is connected in series with the inductor 68, oscillation in a wider band is possible.

  Reference numeral 78 denotes a PLL circuit, and an oscillation signal of the local oscillator 56 is frequency-divided by frequency dividers 57 and 66 and supplied to an input 78 a of the PLL circuit 78. A microcomputer 79 is inserted between the input 78b and the channel input device 80. Then, a signal indicating the desired reception channel input from the channel input device 80 is supplied to the PLL circuit 78 via the microcomputer 79.

  Furthermore, the PLL circuit 78 includes the variable capacitance diodes 82, 84, 86, 89, 96, 98, 102, 107 of the single tuning filter 52, the double tuning filter 54, the single tuning filter 62, and the double tuning filter 64 (FIG. 2, FIG. 2). 3) and a tuning voltage is supplied to the oscillation variable capacitance diode 69.

  FIG. 2 is a circuit diagram of the single tuning filter 52 and the double tuning filter 54 in the UHF signal receiver 60 according to the first embodiment. Hereinafter, the single tuning filter 52 and the double tuning filter 54 according to the first embodiment will be described with reference to the drawings.

  First, the single tuning filter 52 will be described. In FIG. 2, reference numeral 81 denotes an inductor. A variable capacitance diode 82 is connected in series with the inductor 81, and one of the inductors 83 is connected to the cathode side of the variable capacitance diode 82. The other side of the inductor 83 is connected to the cathode side of the variable capacitance diode 84, and the anode side thereof is grounded via a capacitor. Reference numeral 52a denotes a frequency variable terminal which is connected to the cathode side of the variable capacitance diodes 82 and 84 via a resistor, and is supplied with a tuning voltage from the output of the PLL circuit 78.

  The inductor 81, the variable capacitance diode 82, the inductor 83, and the variable capacitance diode 84 constitute the single tuning filter 52. In the single tuning filter 52, the tuning frequency can be changed by changing both the capacitances of the variable capacitance diodes 82 and 84 in accordance with the tuning voltage supplied to the frequency variable terminal 52a. In the present embodiment, the single-tuned filter 52 uses a filter constant that allows a UHF band signal to pass therethrough.

  Next, the double-tuned filter 54 will be described. The double-tuned filter 54 includes a variable capacitance diode 86, an inductor 87 connected in parallel to the variable capacitance diode 86, an inductor 88 mutually inductively coupled to the inductor 87, and a variable capacitance diode connected in parallel to the inductor 88. 89. Reference numerals 54a and 54b denote variable frequency terminals, which are connected to the cathode sides of the variable capacitance diode 86 and the variable capacitance diode 89, respectively, and are supplied with a tuning voltage from the output of the PLL circuit 78.

  In the double tuning filter 54, the capacitances of the variable capacitance diodes 86 and 89 can be changed in accordance with the tuning voltage supplied to the frequency variable terminals 54a and 54b to change the tuning frequency.

  FIG. 3 is a circuit diagram of the single tuning filter 62 and the double tuning filter 64 in the VHF signal receiver 61 according to the first embodiment. Hereinafter, the single tuning filter 62 and the double tuning filter 64 will be described with reference to FIG.

  In FIG. 3, the single tuning filter 62 is composed of an inductor 91, an inductor 92, an inductor 93, an inductor 94, a switch 95, a variable capacitance diode 96, an inductor 97, and a variable capacitance diode 98. The inductor 91 and the inductor 92 are connected in series, and the inductor 93 and the inductor 94 are connected in series between the connection point 99 and the ground. A switch 95 is inserted between a connection point 100 between the inductor 93 and the inductor 94 and a connection point 101 between the inductor 92 and the anode side of the variable capacitance diode 96. On the other hand, one end of an inductor 97 is connected to the cathode side of the variable capacitance diode 96, and a variable capacitance diode 98 is connected between the other end of the inductor 97 and the ground.

  Reference numeral 62a denotes a frequency variable terminal, which is connected to the cathode side of the variable capacitance diode 98 via a resistor and is supplied with a tuning voltage from the output of the PLL circuit 78. In the single tuning filter 62, the capacitances of the variable capacitance diodes 98 and 96 change according to the tuning voltage supplied to the frequency variable terminal 62a, and the tuning frequency changes. In the present embodiment, the single-tuned filter 62 uses a filter constant that allows a signal in the VHF band to pass.

  Next, the double-tuned filter 64 includes a variable capacitance diode 102 inserted between the input and the ground, a series connection body of inductors 103 and 104 connected in parallel to the variable capacitance diode 102, and a parallel connection with the inductor 104. Is connected to the switch 108. Inductors 105 and 106 are connected in series so as to be inductively coupled to the inductors 103 and 104, and a variable capacitance diode 107 is connected in parallel with the series connection body of the inductors 105 and 106.

  Reference numeral 64a denotes a frequency variable terminal, which is connected to the cathode side of the variable capacitance diodes 102 and 107 through resistors, and is supplied with a tuning voltage from the PLL circuit 78. In the double tuning filter 64, the tuning frequency can be changed by changing the capacitances of the variable capacitance diodes 102 and 107 in accordance with the tuning voltage supplied to the frequency variable terminal 64a.

  Next, in the high frequency receiving apparatus according to the first embodiment, the UHF broadcast band (used as an example of the first frequency band) and the VHF broadcast band (the first one arranged continuously below the UHF broadcast band) A case of receiving a TV broadcast consisting of 2 frequency bands) will be described.

  (Table 1) is a table showing the state of each change-over switch when receiving each broadcast band.

  As shown in Table 1, when receiving the UHF broadcast band, a voltage of 5 V is supplied to the variable capacitance diode 74 and a voltage of 5 V is supplied to the variable capacitance diode 75. Further, the switch 67a is turned on so that the output of the frequency divider 57 is connected to the switch 67.

  Next, when receiving the VHF high-band broadcasting band, a voltage of 5 V is supplied to the variable capacitance diode 74 and a voltage of 0 V is supplied to the variable capacitance diode 75. The switch 67 turns on the switch 67b and turns on the switches 95, 108, and 109 so that the output of the frequency divider 66a is connected.

  When receiving the VHF low band broadcast band, a voltage of 0V is supplied to the variable capacitance diode 74 and a voltage of 5V is supplied to the variable capacitance diode 75. The switch 67 turns on the switch 67c and turns off the switches 95, 108, and 109 so that the output of the frequency divider 66b is connected.

  The high frequency amplifiers 53 and 63 turn on the high frequency amplifier 53 when receiving the UHF broadcast band, and turn on the high frequency amplifier 63 when receiving the VHF broadcast band. This is because the high-frequency signal that has passed through the single-tuned filter 52 or 62 is not supplied to the mixer 55 or 65 by turning off the high-frequency amplifier on the non-receiving side. As a result, only the high-frequency signal desired to be received is converted into an intermediate frequency signal.

  In the first embodiment of the present invention, the inductor 68 of the local oscillator 56 is 8 nH, the capacitor 70 is 47 pF, the variable capacitance diode 69 changes from 41 pF to 2.7 pF from 1 V to 25 V, and the variable capacitance diode. 74 changes from 5 pF to 1.5 pF from 0 V to 5 V, and the variable capacitance diode 75 uses one that changes from 15 pF to 1.5 pF from 0 V to 5 V.

  The local oscillator 56 configured as described above oscillates at a frequency of 350 MHz to 850 MHz when receiving the UHF broadcast band, oscillates at a frequency of 358 MHz to 814 MHz when receiving the VHF high band broadcast band, and receives the VHF low band broadcast band. The frequency from 404 MHz to 692 MHz can be oscillated.

  Further, when receiving the UHF broadcast band, the oscillation signal of the local oscillator 56 is divided by 1/1 by the frequency divider 57 and supplied to the mixer 55 to obtain an intermediate frequency signal of 45.75 MHz. On the other hand, when receiving the VHF high-band broadcasting band, the oscillation signal of the local oscillator 56 is divided by half by the frequency divider 66a and supplied to the mixer 65 to obtain an intermediate frequency signal of 45.75 MHz. Finally, in NTSC broadcasting, when receiving the VHF low-band broadcast band, the oscillation signal of the local oscillator 56 is divided by a quarter by the frequency divider 66b and supplied to the mixer 65 to provide an intermediate frequency signal of 45.75 MHz. Have gained.

  In the first embodiment, all the frequency dividers 57, 66a, 66b include a program counter, and the PLL circuit sets the frequency division ratio values to the program counters of the frequency dividers 57, 66a, 66b according to the reception channel. Send the data to be set. As a result, even when different broadcast signals such as NTSC broadcast and PAL broadcast are received, it is possible to easily cope with this by simply changing the value of the division ratio of the program counter.

  When the frequency division ratio of the frequency divider 57 is 1/1 as in the first embodiment, it is not necessary to prepare the frequency divider 57 in particular, and the output of the local oscillator 56 is supplied to the switch 67. You may connect directly. In this case, since it is not necessary to provide the frequency divider 57, a low-cost high-frequency receiving device can be realized. Further, since the signal input to the mixer 55 does not pass through the frequency divider 57, the signal loss of the local oscillator 56 is small. Therefore, it is possible to obtain a high frequency receiving apparatus having a good C / N.

  Next, FIG. 4 shows the frequency characteristics of the local oscillation signal input to the single tuning filters 52 and 62 and the double tuning filters 54 and 64 and the mixer 55 or 65 as the tuning filters in the first embodiment. FIG. 6 is a characteristic diagram in which the horizontal axis represents the reception channel and the vertical axis represents the tuning voltage.

  In FIG. 4, reference numeral 111 denotes a tuning voltage characteristic from the reception channel 2 channel to the B channel (55.25 MHz to 127.25 MHz) of the single tuning filter 62 and the double tuning filter 64 as a tuning filter when receiving the VHF low band broadcast band. Show. Similarly, reference numeral 112 denotes a tuning voltage characteristic from the reception channel C channel to the KK channel (133.25 MHz to 361.25 MHz) of the single tuning filter 62 and the double tuning filter 64 as the tuning filters when receiving the VHF high band broadcast band. ing. Reference numeral 113 denotes a tuning voltage characteristic for the receiving channel LL channel to 69 channel (367.25 MHz to 801.25 MHz) of the single tuning filter 52 and the double tuning filter 54 as tuning filters at the time of receiving the UHF broadcast band. .

  Reference numeral 114 denotes a tuning voltage characteristic from the reception channel 2 channel to the B channel (101 MHz to 173 MHz) of the local oscillator 56 when the VHF low-band broadcast band is received. Similarly, reference numeral 115 denotes a tuning voltage characteristic from the reception channel C channel to the KK channel (179 MHz to 407 MHz) of the local oscillator 56 at the time of receiving the VHF high band broadcast band, and reference numeral 116 denotes reception of the local oscillator at the time of receiving the UHF broadcast band. The characteristics of tuning voltage from channel LL channel to 69 channel (413 MHz to 847 MHz) are shown.

  Here, it is important to set the tuning voltages of the single tuning filters 52 and 62 and the double tuning filters 54 and 64 in each channel and the tuning voltage of the local oscillator to substantially the same value in each broadcasting band. That is, it is necessary to approximate the tuning voltage characteristics for the channels of the single tuning filters 52 and 62 and the double tuning filters 54 and 64 in all broadcast bands. In order to obtain an intermediate frequency signal by the mixers 55 and 65, the intermediate oscillator 56 and the frequency divider always link only the intermediate frequency in conjunction with the tuning frequencies of the single tuning filters 52 and 62 and the double tuning filters 54 and 64. This is because it is necessary to obtain a high signal. This is the most important basic performance in receiving a high frequency signal in the high frequency receiver.

  By doing so, it is possible to receive all the continuous US television channels from 55.25 MHz to 801.25 MHz from the VHF low band broadcast band to the UHF broadcast band.

  Therefore, in the first embodiment of the present invention, the capacitance value in the tuning unit 72 constituting the local oscillator 56 is slightly changed by changing the respective voltages supplied from the control circuit 76 to the variable capacitance diodes 74 and 75. Thus, the local oscillation frequency characteristic with respect to the tuning voltage suitable for each reception broadcast band is obtained.

  Here, when 0 V is supplied to the variable capacitance diode 74, a capacitance of 5 pF is inserted in parallel with the oscillation variable capacitance diode 69. As a result, when the capacitance of the oscillation variable capacitance diode 69 is small, the contribution of the capacitance value of the oscillation variable capacitance diode 69 to the oscillation frequency of the local oscillator 56 is reduced. Therefore, the oscillation frequency at a high frequency of the local oscillator 56 in which the capacitance of the oscillation variable capacitance diode 69 becomes small can be changed.

  Further, when 0 V is supplied to the variable capacitance diode 75, a capacitance of 15 pF is inserted in parallel with the capacitor 70. As a result, the capacitance connected in series with the oscillating variable capacitance diode 69 changes in the direction of increasing, so that the change ratio of the oscillating variable capacitance value with respect to the oscillation frequency in the local oscillator 56 increases, and the oscillation with respect to the tuning voltage The frequency range can be changed.

  Thereby, if the voltage supplied to the variable capacitance diodes 74 and 75 is supplied according to the reception band and the reception channel, those capacitance values can be appropriately selected, so that the UHF broadcast band, the VHF high band broadcast band, The characteristics of the channel (frequency) and the tuning voltage can be determined independently in each frequency band of the VHF low-band broadcast band.

  Accordingly, by appropriately changing the capacitance values of the variable capacitance diodes 74 and 75, the tuning voltage characteristics for the reception channel (frequency) of the local oscillator 56 in each band can be changed to the single tuning filters 52 and 62 and the double tuning filters 54 and 64. Approximate the tuning voltage characteristics for the receiving channel (frequency).

  These control the voltage supplied to the variable capacitance diodes 74 and 75 in accordance with the frequency band received by the control circuit according to the instruction from the microcomputer 79, so that 55.25 MHz from the VHF broadcast band to the UHF broadcast band. Will be able to receive all continuous television channels from US to 801.25 MHz.

  In the high frequency receiving apparatus according to the first embodiment, all of the oscillation variable capacitance diode 69, the variable capacitance diodes 84, 86, and 89 (FIG. 2) and the variable capacitance diodes 98, 102, and 107 (FIG. 3) are omitted. Those having the same capacity change characteristics are used. This makes it easy to approximate the tuning frequency characteristics with respect to the tuning voltage of the tuning unit in the single tuning filters 52 and 62 and the double tuning filters 54 and 64 and the local oscillator 56 with respect to the tuning voltage.

  Here, the oscillation variable capacitance diode 69, the variable capacitance diodes 84, 86, and 89 (FIG. 2) and the variable capacitance diodes 98, 102, and 107 (FIG. 3) include a single tuning filter 62 corresponding to the VHF broadcast band. A variable capacitance diode 98 that has the same capacitance change ratio as that required to change the tuning frequency is used.

  This is because the largest capacity change ratio is required for the VHF band, particularly the VHF high band. As a result, the oscillation variable capacitance diode 69, the variable capacitance diodes 84, 86 and 89 (FIG. 2) and the variable capacitance diodes 98, 102 and 107 (FIG. 3) can all be of the same product number. Management becomes easier. In addition, it is difficult for a component mistake or the like to occur when the component is mounted.

  In the first embodiment of the present invention, the oscillator 71, the frequency dividers 57 and 66, the mixers 55 and 65, and the PLL circuit 78 and the control circuit 76 are integrated into one package. Yes. Thereby, a high frequency receiver can be reduced in size.

  Further, this integrated circuit has terminals 121 and 122 to which both ends of the inductor 68 are connected, and terminals 123 and 124 to be connected to respective cathode side terminals of the variable capacitance diodes 74 and 75. Terminals 123 and 124 are arranged between the terminals 121 and 122. As a result, the connections between the components of the variable capacitance diode 69, the inductor 68, the capacitor 70, and the variable capacitance diodes 74 and 75 constituting the tuning unit and the terminals 121, 122, 123, and 124 of the integrated circuit are wired as short as possible. Therefore, it is possible to reduce the unnecessary capacitance component and inductor component and to design with high quality.

(Embodiment 2)
In the second embodiment, reception of the UHF broadcast band and reception of the VHF broadcast band are performed by one mixer 131. Therefore, it contributes to miniaturization and price reduction. The second embodiment will be described below. In addition, about the same thing as Embodiment 1, the same code | symbol is attached | subjected and description is simplified.

  FIG. 5 is a block diagram of the high frequency receiving apparatus according to the second embodiment. In FIG. 5, 132 is an input terminal to which broadcast waves in the UHF broadcast band and the VHF broadcast band are input. The input terminal 132 has a single-tuned filter 52 that passes the UHF broadcast band, a high-frequency amplifier 53, a first series connection body connected in this order of the double-tuned filter 54, and a single-pass filter that passes the VHF broadcast band. The tuning filter 62, the high frequency amplifier 63, and the second series connection body connected in this order of the double tuning filter 64 are connected in parallel.

The output of the parallel connection body is connected to one input of a mixer 131 provided in the integrated circuit 133. The output of the mixer 131 is connected to an output terminal 135 via an intermediate frequency filter 58 and an intermediate frequency amplifier 134.

  On the other hand, the output of the changeover switch 67 is connected to the other input of the mixer 131. The output of the changeover switch 67 is also connected to the PLL circuit 78. Note that the frequency divider 57 can be omitted when receiving UHF broadcast waves. That is, the frequency division ratio can be set to 1.

  Further, the first tuning filter 62 that passes the VHF broadcast band, the high-frequency amplifier 63, and the second series connection body connected in this order of the double-tuned filter 64 is used only to pass the UHF broadcast band. It is also possible to realize a high-frequency receiver dedicated to the VHF broadcast band by omitting the serial connection body.

  The operation of the high frequency receiving apparatus in the second embodiment is the same as that in the first embodiment except that the mixer 131 mixes the UHF broadcast band and the VHF broadcast band.

  In the integrated circuit 133 in the present embodiment, a mixer 131, a changeover switch 67, frequency dividers 57 and 66, an oscillation unit 71 of a local oscillator 56, a control circuit 76, and an intermediate frequency amplifier 134 are integrated. ing. Since it is integrated in this way, it can contribute to miniaturization and high performance.

  The high-frequency receiving apparatus according to the present invention has an effect of being able to receive a wideband channel of a continuous VHF broadcast band and UHF broadcast band, and is particularly useful when used for a television, a DVD, or the like.

Block diagram of the high-frequency receiving device according to Embodiment 1 of the present invention Circuit diagram of tuned filter receiving UHF band The circuit diagram of the tuning filter that receives the VHF band The characteristic diagram of tuning voltage for receiving channel of tuning filter and local oscillator FIG. 6 is a block diagram of the high frequency receiving apparatus according to the second embodiment of the present invention. Same as above, block diagram of conventional high-frequency receiver Same characteristic diagram of tuning voltage with respect to local oscillation signal supplied to mixer

51 Input Terminal 52 Single Tuning Filter 54 Double Tuning Filter 55 Mixer 56 Local Oscillator 57 Divider 59 Output Terminal 60 UHF Signal Receiver 61 VHF Signal Receiver 62 Single Tuning Filter 64 Double Tuning Filter 65 Mixer 66 Divider 68 Inductor 69 Oscillating variable capacitance diode 70 Capacitor 71 Oscillating unit 72 Tuning unit 73 Oscillation frequency changing means 74 Variable capacitance diode 75 Variable capacitance diode 76 Control circuit 77 Variable capacitance diode 78 PLL circuit 73 Oscillation frequency changing means 74 Variable capacitance diode 75 Variable capacitance Diode 76 Control circuit 77 Variable capacitance diode 78 PLL circuit

Claims (11)

In a high-frequency receiving apparatus that receives a first frequency band and a high-frequency signal in a second frequency band lower than the first frequency band, the high-frequency receiving apparatus has both the first and second frequency bands. In order to pass a high-frequency signal in the first frequency band from the input input terminal and the signal supplied to the input terminal, a first frequency whose tuning frequency changes due to a change in capacitance of the first variable capacitance diode A first receiver comprising a tuning filter and a first mixer whose output is fed to one of its inputs and whose output is fed to an output terminal; and said input terminal A second tuning filter whose tuning frequency is changed by the capacitance change of the second variable capacitance diode in order to pass the high-frequency signal in the second frequency band from among the signals supplied to A second receiver comprising a second mixer, the output of the second tuned filter being connected to one of its inputs, the output of which is supplied to the output terminal; the first mixer; A local oscillator and at least one frequency divider for supplying a local oscillation signal to the other input of each of the second mixers, and an output of the local oscillator is supplied to the local oscillator and the local oscillator; A PLL circuit that tunes and controls the first and second tuning filters to the reception channel. The local oscillator includes an oscillation unit, a tuning unit connected to an input of the oscillation unit, the tuning unit, and the oscillation unit. The tuning unit comprises a series connection body of an oscillation variable capacitance diode and a first capacitor, and an inductor connected in parallel to the series connection body, First The variable capacitance diode and the second variable capacitance diode and the oscillation variable capacity diode and the required capacitance change ratio with respect to the frequency bandwidth required the largest capacitance change ratio of the received frequency band values substantially With the same capacitance change characteristic, the PLL circuit supplies a tuning voltage to the first variable capacitance diode, the second variable capacitance diode, and the oscillation variable capacitance diode, and the oscillation frequency changing means includes: A third variable capacitance diode connected in parallel with the oscillation variable capacitance diode, a fourth variable capacitance diode connected in parallel with the first capacitor, and each of the third and fourth variable capacitance diodes. A control circuit connected between a cathode side terminal and the PLL circuit, and the control circuit is configured to control the third and fourth according to the frequency band to be received. When receiving the first frequency band by changing the voltage to be supplied to the variable capacitance diode, when interlocking with the frequency characteristics of the first tuning filter and receiving the second frequency band Is a high-frequency receiver that obtains oscillation signals that differ by a predetermined frequency in conjunction with the frequency characteristics of the second tuning filter. The high frequency receiver according to claim 1, wherein a fourth variable capacitance diode is provided in series with the inductor. In a high-frequency receiving apparatus that receives a high-frequency signal by dividing it into at least a first frequency band and a second frequency band lower than the first frequency band, the high-frequency receiving apparatus includes: an input terminal; A signal input to the input terminal is supplied, a tuning filter whose tuning frequency is changed by a change in capacitance of the first variable capacitance diode, an output of the tuning filter is supplied to one input thereof, and the other The input of the local oscillator is supplied with the output of a local oscillator, converts a first signal in the first frequency band to an intermediate frequency, an output terminal to which the output of the mixer is supplied, and the first When the second signal in the second frequency band is received, the second oscillator is provided between the local oscillator and the mixer to convert the signal in the second frequency band to the intermediate frequency. A frequency divider, a changeover switch that selectively supplies the mixer according to a frequency band for receiving either the output of the frequency divider or the output of the local oscillator, and the local oscillator; A PLL circuit that performs tuning control of the tuning filter to a reception channel, and the local oscillator is inserted between the tuning unit connected to the input of the oscillation unit, the tuning unit, and the oscillation unit The tuning unit includes a series connection body of an oscillation variable capacitance diode and a first capacitor, and an inductor connected in parallel to the series connection body. substantially equal capacitance varying with the value of the required capacitance change ratio with respect to the frequency bandwidth required the largest capacitance change ratio of the frequency band to receive the variable capacitance diode and the oscillation variable capacity diode The PLL circuit supplies a tuning voltage to the first variable capacitance diode and the oscillation variable capacitance diode, and the changeover switch is switched according to a frequency band to be received, and the oscillation frequency change The means includes a second variable capacitance diode connected in parallel with the oscillation variable capacitance diode, a third variable capacitance diode connected in parallel with the first capacitor, and the second and third variable capacitance diodes. And a control circuit connected between each of the cathode side terminals and the PLL circuit. The control circuit changes the voltage supplied to the second and third variable capacitance diodes according to the received frequency band. Thus, an oscillation signal that differs by a predetermined frequency in conjunction with the frequency characteristic of the tuning filter is obtained for each frequency band. High frequency receiver. In a high-frequency receiving apparatus that receives a high-frequency signal by dividing it into at least a first frequency band and a second frequency band lower than the first frequency band, the high-frequency receiving apparatus includes: an input terminal; A signal input to the input terminal is supplied, a tuning filter whose tuning frequency is changed by a change in capacitance of the first variable capacitance diode, an output of the tuning filter is supplied to one input thereof, and the other The input of the mixer is connected to the output of the divider whose frequency dividing ratio is changed according to the frequency band to be received, the output terminal to which the output of the mixer is supplied, and the input of the divider And a PLL circuit to which the output signal of the frequency divider is supplied. The local oscillator includes an oscillating unit and a tuning unit connected to an input of the oscillating unit. The tuning unit is connected in parallel with the series connection body of the oscillation variable capacitance diode and the first capacitor, and is composed of an oscillation frequency changing means inserted between the oscillation section and the oscillation section. and a inductor, the first variable capacitance diode and the oscillation variable capacity diode and the required capacitance change ratio values for the frequency bands most significant capacitance change ratio is required within the receiving frequency band The PLL circuit is supplied with the output of the local oscillator, supplies a tuning voltage to the first variable capacitance diode and the oscillation variable capacitance diode, and receives the frequency band. And the oscillation frequency changing means includes a second variable capacitance diode connected in parallel with the oscillation variable capacitance diode, and a second variable capacitance diode. And a control circuit connected to the cathode side terminals of the second and third variable capacitance diodes, the control circuit corresponding to the frequency band to be received. Changing the voltage supplied to the second and third variable capacitance diodes, and changing the oscillation frequency characteristic of the local oscillator with respect to the tuning voltage supplied from the PLL circuit in each frequency band to be received, A high-frequency receiver that obtains a frequency divider output that differs by a predetermined frequency in conjunction with the frequency characteristics of a tuning filter. The frequency divider is composed of a plurality of frequency dividers, and the plurality of frequency dividers are connected to a changeover switch that selectively switches according to a frequency band for receiving a signal input to the mixer. 4. The high frequency receiving device according to 4 . The frequency divider includes a first fixed frequency divider that divides the output frequency of the local oscillator by 1/2, and an output of the first fixed frequency divider is connected to the common terminal and one of the outputs Connected to the other terminal of the mixer, and inserted between the other terminal of the changeover switch and the other terminal of the mixer to further output the output signal of the first fixed frequency divider The high-frequency receiving device according to claim 4 , further comprising a second fixed frequency divider that divides the frequency by half. The tuning filter includes a first tuning filter that tunes to a frequency within the first frequency band, and a second tuning filter that is provided in parallel with the first tuning filter and tunes to a frequency within the second frequency band. The high frequency receiver according to claim 4 , comprising: An integrated circuit comprising: a first mixer, a second mixer, a PLL circuit, an oscillation unit, a frequency divider, and a control circuit that form the high-frequency receiving device according to claim 1 . 4. An integrated circuit, wherein a mixer, a PLL circuit, an oscillation unit, and a frequency divider that form the high-frequency receiving device according to claim 3 are integrated at least. 5. An integrated circuit, wherein a mixer, a PLL circuit, an oscillating unit, a frequency divider, and a control circuit forming the high-frequency receiving device according to claim 4 are integrated at least. An input of the PLL circuit in the high frequency receiver according to claim 1 or claim 4, is connected to the input of the control circuit, a microcomputer tuning signal indicating a desired reception channel by operation of the operator is input And the microcomputer causes the PLL circuit to supply a tuning voltage corresponding to the channel selection signal, and causes the control circuit to supply a voltage corresponding to the channel selection signal.

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