KR100384885B1 - Transceiver of mobile communication terminal for dual band/tri mode - Google Patents

Abstract

The present invention relates to a transceiver of a mobile terminal for a dual band / tree mode, and includes a local frequency generator for generating CDMA and APS local frequencies and a PCS local frequency, a diplexer, a PCS duplexer, and a CDMA and AAMP duplexer. First and second LNA and RF SAW filters for low noise amplification and noise cancellation for each RF frequency, and PCS and CDMA and AAMP methods for generating RF and local frequencies through the first and second RF SAW filters. First to third mixers for outputting a receiving side IF frequency having the same band by mixing the PCS local frequency and the CDMA and AMPS local frequencies generated from the negative unit, and the PCS output from the first and second mixers through a switching operation. The first and second IF BPFs for band-passing the receiving-side IF frequency by the CDMA method and the receiving-side IF frequency by the AMPS method output from the third mixer and outputting them to the IFR, and the MSM's swap PCS local frequency and CDMA / AMPS local frequency inputted from local frequency generator and switching IF frequency by PCS method and transmitter IF frequency by CDMA and AMPS method IFT which outputs RF frequency by RF method and RF frequency by CDMA and AMPS method, and RF frequency by PCS method and RF frequency by CDMA and AMPS method which are output from IFT. And a third RF SAW filter and a PA.

Description

Transceiver of mobile terminal for dual band / tree mode {TRANSCEIVER OF MOBILE COMMUNICATION TERMINAL FOR DUAL BAND / TRI MODE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transceiver of a mobile communication terminal for dual band / tri mode. In particular, in a mobile communication terminal for dual band or tree mode, the IF frequency used at the receiving side is Reduce the number of IF Bandpass Filters (hereinafter referred to as 'BPF') used by the receiver by changing each of the IF frequencies used by the transmitter and having different frequency bands. Transceiver of dual band / tree mode mobile communication terminal to simplify circuit design by reducing the number of components and the area occupied by reducing the number of voltage control oscillators (VCOs) that generate local frequency. It is about.

In general, a mobile communication terminal of a mobile communication system is classified into a personal communication service (PCS) method, a code division multiple access (CDMA) method, and an advanced mobile phone (AMPS) method. In this case, the PCS method is 1850 to 1910 MHz. The transmission frequency of the band and the reception frequency of the 1930 to 1990 MHz band are used, and the transmission frequency of the 824 to 894 MHz band and the reception frequency of the 869 to 894 MHz band are used for the CDMA and AMPS systems.

Conventionally, the mobile communication terminal using the PCS method and the CDMA method is called a dual band mobile communication terminal, and the mobile communication terminal using the PCS method, the CDMA method, and the AMPS method is called a tree mode mobile communication terminal. Another method is to design a mobile communication terminal capable of a mobile communication service.

In the transceiver of the conventional dual band / tree mode mobile communication terminal, as shown in the block diagram shown in FIG. 1, the first mixer 31 at the receiving side of the mobile communication terminal is a diplexer 11 and a PCS. RF frequency in the 1930 to 1990 MHz band through a duplexer (12), the PCS method passed through a first Low Noise Amplifier (LNA) 21 and a first RF Surface Acoustic Wave (SAW) filter 23; The receiver IF frequency of 210.38 MHz is output by mixing the PCS local frequencies of the 1719.62 to 1779.62 MHz bands output from the second VCO 42.

The second mixer 32 passes through the diplexer 11 and the CDMA and AMPS duplexers 13 and passes through the second LNA 22 and the second RF SAW filter 24. RF frequency of ˜894 MHz band and CDMA and AMPS local frequencies of 954.38 to 979.38 MHz band output from first VCO 41 are mixed to output a receiving side IF frequency of 85.38 MHz band, and third mixer 33 is RF frequency in the 869 to 894 MHz band and the second frequency, which are passed through the diplexer 11 and the CDMA and AMPS duplexers 13 and passed through the second LNA 22 and the second RF SAW filter 24. 1 Outputs the receiving side IF frequency in the 85.38 MHz band by mixing the CDMA and AMPS local frequencies in the 954.38 to 979.38 MHz band output from the VCO 41.

Subsequently, the first IF BPF 34 having a bandwidth of 1.25 MHz passes the receiving side IF frequency of the 210.38 MHz band by the PCS method output from the first mixer 31 and has a second bandwidth of 1.25 MHz. IF BPF 35 passes the receiving side IF frequency in the 85.38 MHz band by the CDMA method output from the second mixer 32, and the third IF BPF 36 having a bandwidth of 30 KHz is the third mixer ( Pass the IF side of the receiving side of the 85.38MHz band by the AMPS method output from 33).

Thereafter, the intermediate frequency receiver (IFR) 38 passes through the first IF BPF 34 and then receives the IF side of the 210.38 MHz band input through the first switch 37 and the second IF BPF ( After receiving 35, the receiving side IF frequency of the 85.38MHz band input through the first switch 37 and the receiving side IF frequency of the 85.38MHz band passing through the third BPF 36 are processed.

The IFT (Intermediate Frequency Transmitter) 51 at the transmitting side mixes the transmitted IF frequency in the 130.38 MHz band, which has been transmitted, with each local frequency input through the second switch 44, thereby providing 1850 through PCS. Outputs RF frequency of 1910MHz band, RF frequency of CDMA, AAMP method and RF frequency of 824-849MHz band respectively.

That is, the IFS of 130.38 MHz band through the mixer (not shown) in the IFT 51 and the PCS local frequency of the 1719.62 to 1779.62 MHz band of the second VCO 42 input through the second switch 44 are adjusted. RF frequency of 1850 to 1910 MHz band by PCS method is mixed, and IF frequency of 130.38 MHz band and CDMA of 954.38 to 979.38 MHz band of the first VCO 41 input through the second switch 44. And the APS local frequency are mixed to output an RF frequency in the 824 to 849 MHz band using the CDMA and AAMP methods.

As described above, the receiving side IF frequency used in the PCS scheme and the receiving side IF frequency used in the CDMA and AMP schemes are different from each other in the 210.38 MHz band and the 85.38 MHz band, respectively, and the transmitting side IF frequency and the CDMA used in the PCS scheme are different. In the AMPS method, the transmitting IF frequency is the same in the 130.38MHz band.

That is, the receiving side of the mobile communication terminal uses different IF frequencies according to the PCS scheme, CDMA, and AMPS schemes, and the transmitting side shares one IF frequency.

The bandwidth of the PCS and CDMA schemes is the same as 1.25 MHz, but the bandwidth of the AMPS scheme is 30 KHz, which is different from that of the PCS and CDMA schemes.

Accordingly, in the conventional dual band / tree mode mobile communication terminal, three different IF BPFs (34, 35, 36) are used at the receiving side because the IF frequencies and bandwidths for the three modes of PCS, CDMA, and AMPS are different. do.

In addition, since the PCS scheme and the CDMA and AMPS schemes are different from each other in the frequency band of the local frequency, two VCOs 41 and 42 are required.

However, as described above, the conventional dual band / tree mode mobile communication terminal uses three IF BPFs and two VCOs, not only takes up a lot of circuit design area in the transceiver design but also consumes a lot of component costs, and also provides a different method. There was a problem that can cause the call drop (Call Drop) problem when the handoff (Handoff) due to the noise problem when switching to.

The present invention has been made to solve the above problems, and its object is to have the same frequency band as the IF frequency of the PCS method and the IF frequency of the CDMA and AMPS types used in the receiving side of the mobile terminal for dual band or tree mode. Change the PC frequency IF frequency and CDMA / AMPS IF frequency used by the transmitter to have different frequency bands, and remove one of the three IF BPFs used by the receiver. The aim is to provide a transceiver for a dual-band / tree mode mobile terminal that can reduce component count and footprint, thereby reducing component cost and simplifying circuit design.

1 is a block diagram of a transceiver of a conventional mobile communication terminal for dual band / tree mode;

2 is a block diagram of a transceiver of a mobile terminal for dual band / tree mode according to an embodiment of the present invention;

3 is a block diagram of a transceiver of a mobile terminal for dual band / tree mode according to another embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

11: diplexer 12: PCS duplexer

13: CDMA, AMPS duplexer 21,22: 1st, 2nd LNA

23,24: 1st, 2nd RF SAW filter 31, 32, 33: 1st, 2nd, 3rd mixer

34: first switch 35,36: first and second IF BPF

37: IFR 41: VCO

42: second switch 43-1: multiplexer

43-2: Divider 44: MSM

45: third switch 51: IFT

52,53: third and fourth RF SAW filters 54,55: first and second PAs

In the transceiver of the dual-band / tree mode mobile communication terminal of the present invention for achieving the above object, in the transceiver of the dual-band / tree mode mobile communication terminal respectively operating in accordance with the PCS method, CDMA, AMPS method, Frequency band where the receiving side IF frequency by PCS method and the receiving side IF frequency by CDMA and AMP method have the same frequency band, and the transmitting IF frequency by PCS method and the transmitting IF frequency by CDMA and AMPS method are different. Local noise generator which generates CDMA, AMPS local frequency and PCS local frequency to reduce the noise, attenuates each RF frequency received through diplexer, PCS duplexer and CDMA, AMPS duplexer, and removes noise. RF frequency and local frequency generation by the PCS scheme, the CDMA, and the AMPS scheme passing through the first and second LNA and RF SAW filters and the first and second RF SAW filters. First to third mixers for outputting the receiving side IF frequencies having the same band by mixing the PCS local frequency, the CDMA, and the AMPS local frequencies generated by the respective units, and outputted from the first and second mixers through a switching operation. Switching control of the first and second IF BPFs and the MSM, which pass-band-receives the receiving IF frequency by the PCS method and the CDMA method and the receiving IF frequency by the AMPS method output from the third mixer and outputs them to the IFR. PCS method by mixing PCS local frequency and CDMA, AMPS local frequency and PC-side IF frequency and CDMA / AMPS-based IF frequency input from the local frequency generator through switching operation according to signal. IFT for outputting RF frequency by RF and RF frequency by CDMA and AMPS method, RF frequency by PCS method and RF frequency by CDMA and AMPS method output from the IFT And a third and fourth RF SAW filters and a PA for removing noise and power amplifying each signal.

Hereinafter, a configuration and operation of a transceiver of a mobile communication terminal according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a block diagram of a transceiver of a dual band / tree mode mobile communication terminal according to an embodiment of the present invention, in which a PCS duplexer, a CDMA, and an AMPS operate in accordance with a PCS scheme or a CDMA / AMPS scheme, respectively. A diplexer 11 for coupling a duplexer, a PCS duplexer 12 for transmitting and receiving signals by the PCS method, and a CDMA and AAMP duplexer 13 for transmitting and receiving signals according to the CDMA and AMPS methods. do.

First and second LNAs 21 and 22 for low noise amplifying each RF frequency received from the PCS duplexer 12 and the CDMA and AAMP duplexers 13, and the first and second LNAs 21 and 22. RF frequencies in the 1930 to 1990 MHz band by the first and second RF SAW filters (23 and 24) for removing the noise of each RF frequency amplified by the PCS) and the PCS scheme passed through the first RF SAW filter (23). And a first mixer 31 for mixing a PCS local frequency in a 2106 to 2174 MHz band input through a multiplexer and outputting a receiving side IF frequency in an 183.6 MHz band, and a second CDMA scheme passing through the second RF SAW filter 24. A second mixer 32 which outputs a receiving side IF frequency of 183.6 MHz by mixing RF frequencies of 869 to 894 MHz band and CDMA and AAMP local frequencies of 1053 to 1087 MHz band input through the second switch; The RF frequency of the 869 to 894 MHz band by the AMPS method passed through the second RF SAW filter 24 is input through the second switch. A third mixer 33 for mixing CDMA and AAMP local frequencies in the 1053 to 1087 MHz band and outputting a receiving side IF frequency in the 183.6 MHz band; and an IF frequency by the PCS method output from the first mixer 31 and the The first switch 34 for switching the receiving side IF frequency by the CDMA method output from the second mixer 32, and the band-passing pass through the receiving side IF frequency input through the first switch 34 1 IF BPF 35, a second IF BPF 36 for band-passing the receiving side IF frequency by the AMPS method output from the third mixer 33, and the first and second IF BPF ( And an IFR 37 for receiving and processing the receiving IF frequency passed through 35 and 36.

In addition, the receiving IF frequency of the PCS method and the receiving IF frequency of the CDMA and AAMP methods have the same frequency band, and the transmitting IF frequency of the PCS method and the transmitting IF frequency of the CDMA and AMPS methods are different from each other. In order to have a frequency band, the VCO 41 generating the CDMA and AMPS local frequencies in the 1053 to 1087 MHz band and the CDMA and AMPS local frequencies in the 1053 to 1087 MHz band generated in the VCO 41 are switched to the second and the second. The second switch 42, which is output to the third mixers 31 and 32, and the CDMA and AMPS local frequencies of the 1053 to 1087 MHz band inputted through the second switch 42, are multiplied by two, and the PCS of the 2106 to 2174 MHz band are doubled. A multiplexer (43-1) for outputting a local frequency to the first mixer (31), a mobile station modem (MSM) 44 for outputting a switching control signal for generating a local frequency, and the MSM ( The second according to the switching control signal output from A third switch 45 for switching the CDMA, AMPS local frequency in the 1053 to 1087 MHz band input through the position 42 and the PCS local frequency in the 2106 to 2174 MHz band output from the multiplexer 43-1; 3 RF frequency in the 1850 to 1910 MHz band according to the PCS method by mixing the local frequency input according to the switched path in the switch 45 and the transmitting side IF frequency using the PCS method and the transmitting side IF frequency using the CDMA and AMPS methods, respectively. And an IFT 51 for outputting an RF frequency in the 824 to 849 MHz band by the CDMA and AMPS schemes.

In addition, the third and fourth RF SAW filters for removing noise of RF signals of the 1850 to 1910 MHz band by the PCS scheme and RF frequencies of the 824 to 849 MHz band by the CDMA and AAMP schemes, which are output from the IFT 51. First and second power amplifiers 52 and 53 and the RF frequencies passed through the third and fourth RF SAW filters 52 and 53 and output to the PCS duplexer 12 and the CDMA duplexer 13. And second PA (Power Amplifier) 54, 55.

FIG. 3 is a block diagram of a transceiver of a dual band / tree mode mobile communication terminal according to another embodiment of the present invention, in which a PCS duplexer, a CDMA, and an APS are operated so that the mobile communication terminal operates in accordance with a PCS scheme or a CDMA / AMPS scheme, respectively. A diplexer 11 for coupling a duplexer, a PCS duplexer 12 for transmitting and receiving signals by the PCS method, and a CDMA and AAMP duplexer 13 for transmitting and receiving signals according to the CDMA and AMPS methods. do.

First and second LNAs 21 and 22 for low noise amplifying each RF frequency received from the PCS duplexer 12 and the CDMA and AAMP duplexers 13, and the first and second LNAs 21 and 22. RF frequencies in the 1930 to 1990 MHz band by the first and second RF SAW filters (23 and 24) for removing the noise of each RF frequency amplified by the PCS) and the PCS scheme passed through the first RF SAW filter (23). And a first mixer 31 for mixing the PCS local frequency of the 2106 to 2174 MHz band input through the second switch and outputting the receiving side IF frequency of the 183.6 MHz band, and the second RF SAW filter 24. A second mixer 32 for mixing the RF frequency of the 869 to 894 MHz band with the CDMA and AAMP local frequencies of the 1053 to 1087 MHz band output by the divider and outputting the receiving side IF frequency of the 183.6 MHz band; 2 RF band of 869 ~ 894MHz band by AMPS method which passed 2 RF SAW filter 24 and 1053 ~ 1087MHz output from the divider A third mixer 33 for outputting a receiving side IF frequency in an 183.6 MHz band by mixing the inverse CDMA and AAMP local frequencies, and a receiving side IF frequency and the first IF in accordance with the PCS method output from the first mixer 31; The first switch 34 for switching the receiving side IF frequency by the CDMA method output from the mixer 32, and the first pass for limiting the passing of the receiving side IF frequency input through the first switch 34 An IF BPF 35 and a second IF BPF 36 for band-passing a receiving side IF frequency by the AMPS method output from the third mixer 33; and the first and second IF BPFs 35 And an IFR 37 for receiving and processing the receiving side IF frequency passed by 36.

In addition, the receiving IF frequency of the PCS method and the receiving IF frequency of the CDMA and AAMP methods have the same frequency band, and the transmitting IF frequency of the PCS method and the transmitting IF frequency of the CDMA and AMPS methods are different from each other. A VCO 41 for generating a PCS local frequency in the 2106 to 2174 MHz band to have a frequency band,

A second switch 42 for switching the PCS local frequency in the 2106 to 2174 MHz band generated by the VCO 41 to the first mixer 31, and 2106 to 212 inputted through the second switch 42; Divider (43) for dividing the PCS local frequency in the 2174 MHz band by half and outputting the CDMA and AAMP local frequencies in the 1053 to 1087 MHz band by the CDMA and AAMP methods to the second and third mixers 32 and 33. -2), an MSM 44 for outputting a switching control signal for generating a local frequency, and 2106 to 2174 MHz input through the second switch 42 according to the switching control signal output from the MSM 44. According to the third switch 45 for switching the PCS local frequency of the band and the CDMA, AMPS local frequency of the 1053 to 1087 MHz band output from the divider 43-2, and the path switched by the third switch 45 Local frequency to be inputted, IF side by PCS method, CDMA, AMPS method Mixing the IF frequency sincheuk respectively provided with the IFT (51) for outputting a frequency of the RF band by the RF frequency and 824~849MHz CDMA, AMPS scheme 1850~1910MHz band by the PCS method.

In addition, the third and fourth RF SAW filters to remove noise of the RF frequency of the 1850 to 1910 MHz band by the PCS scheme and the RF frequency of the 824 to 849 MHz band by the CDMA / AMPS scheme output from the IFT 51. (52,53), and the power to amplify each RF frequency signal passing through the third and fourth RF SAW filter (52,53) and outputs to the PCS duplexer (12) and CDMA, APS duplexer (13) And second and second PAs 54 and 55.

As described above, the transceiver of the mobile communication terminal for dual band / tree mode according to the present invention uses only two IF BPFs 35 and 36, one of which is reduced in comparison with the related art.

That is, the first IF BPF 35 having a bandwidth of 1.25 MHz passes the receiving side IF frequency of the 183.6 MHz band by the PCS scheme and the receiving side IF frequency of the 183.6 MHz band by the CDMA scheme. It is shared and used by PCS method.

And, since the PCS local frequency is approximately twice the local frequency of CDMA and AMPS, in the present invention, the VCO 41 generating the CDMA and AMPS local frequencies in the 1053 to 1087 MHz band without using two VCOs as in the prior art and The multiplexer 43-1, which generates the PCS local frequency in the 2106 to 2174 MHz band by multiplying the CDMA and AMPS local frequencies in the 1053 to 1087 MHz band generated by the VCO 41, is used.

In another method, the VCO 41 generating the PCS local frequency in the 2106 to 2174 MHz band and the PCS local frequency in the 2106 to 2174 MHz band generated in the VCO 41 are divided by 1/2 to divide the CDMA in the 1053 to 1087 MHz band. The divider 43-2 for generating the APS local frequency is used.

Referring to the operation of the transceiver of the dual-band / tree mode mobile communication terminal according to the present invention configured as described above are as follows.

First, the operation of the transceiver of the mobile terminal for the dual band / tree mode shown in FIG.

The diplexer 11 in the transceiver of the mobile communication terminal combines the PCS duplexer 12 and the CDMA, AMPS duplexer 13 so that the mobile communication terminal operates in accordance with the PCS method or CDMA, AMPS method, respectively, wherein the PCS duplexer ( 12) is responsible for the transmission and reception of signals by the PCS scheme, and the CDMA, AAMP duplexer 13 is responsible for the transmission and reception of signals by the CDMA, AMPS scheme.

The first and second LNAs 21 and 22 low-noise amplify respective RF frequencies received from the PCS duplexer 12 and the CDMA and AMPS duplexers 13, and then the first and second RF SAW filters 23 and 24. ) Removes noise of each RF frequency amplified by the first and second LNAs 21 and 22.

On the other hand, when the VCO 41 generates the CDMA and AMPS local frequencies in the 1053 to 1087 MHz band according to the CDMA and AMPS schemes, the multiplexer 43-1 inputs the CDMA in the 1053 to 1087 MHz band input through the second switch 42. To multiply the APS local frequency by two, the PCS local frequency in the 2106 to 2174 MHz band is generated by the PCS method.

That is, the VCO 41 has the same frequency band as the receiving side IF frequency by the PCS scheme and the receiving side IF frequency by the CDMA / AMPS scheme as 183.6 MHz band, and the transmitting side IF frequency by the PCS scheme and CDMA, AAMPs. In order to ensure that the transmitting side IF frequencies have different frequency bands, CDMA and AMPS local frequencies in the 1053 to 1087 MHz band are generated.

Subsequently, the first mixer 31 has an RF frequency of 1930 to 1990 MHz band by the PCS scheme passed through the first RF SAW filter 23 and a PCS of 2106 to 2174 MHz band input through the multiplexer 43-1. Mixing the local frequencies and outputting the receiving side IF frequency of 183.6MHz band, the second mixer 32 is the RF frequency of 869 ~ 894MHz band by the CDMA method passed through the second RF SAW filter 24 and the first The receiver IF frequency of 183.6 MHz is output by mixing the CDMA and AMPS local frequencies of the 1053 to 1087 MHz band input through the second switch 42, and the third mixer 33 is the second RF SAW filter 24. RF frequency of 869 ~ 894MHz band by AMPS method and CDMA, AMPS local frequency of 1053 ~ 1087MHz band input through the second switch 42 are mixed to output the receiving IF frequency of 183.6MHz band. .

Then, the first IF BPF 35 band-limits and passes the receiving side IF frequency by the PCS scheme inputted through the first switch 34 or the receiving side IF frequency by the CDMA scheme and passes the second IF BPF ( 36) band-limits the receiving side IF frequency by the AMPS method output from the third mixer 33.

Then, the IFR 37 on the receiving side receives and processes the receiving IF frequency signals passing through the first and second IF BPFs 35 and 36.

On the other hand, the IFT 51 of the transmitting side has a CDMA and AAMP local frequency in the 1053 to 1087 MHz band in which the third switch 45 is input through the second switch 42 according to the switching control signal output from the MSM 44. And switching the PCS local frequency in the 2106 to 2174 MHz band output from the multiplexer 43-1, the local frequency input according to the switched path in the third switch 45 and the transmitting side IF frequency by the PCS scheme; The IF side of the CDMA and AMPS systems is mixed to output RF frequencies of the 1850 to 1910 MHz band of the PCS scheme and the RF frequencies of the 824 to 849 MHz band of the CDMA and AMPS schemes.

Subsequently, the third and fourth RF SAW filters 52 and 53 each have an RF frequency in the 1850 to 1910 MHz band using the PCS scheme output from the IFT 51 and an RF frequency in the 824 to 849 MHz band using the CDMA and AAMP schemes. The noise of the signal is removed, and the first and second PAs 54 and 55 power amplify each RF frequency passed through the third and fourth RF SAW filters 52 and 53 to the PCS duplexer 12 and Output to the CDMA, AAMP duplexer (13).

Next, when the operation of the transceiver of the mobile terminal for the dual band / tree mode shown in FIG. 3 will be described, the operation differs only in the portion generating the local frequency, and the remaining operations are the same as described above.

That is, the VCO 41 has the same frequency band as the receiving side IF frequency by the PCS scheme and the receiving side IF frequency by the CDMA / AMPS scheme as 183.6 MHz band, and the transmitting side IF frequency by the PCS scheme and the CDMA / AMPS scheme. If the transmitting side IF frequencies by the PCS local frequency is generated in the 2106 to 2174 MHz band by the PCS scheme in order to have different frequency bands, the divider 43-2 is inputted via the second switch 42 to 2106 to The PCS local frequency in the 2174 MHz band is divided by 1/2 to generate the CDMA and AMPS local frequencies in the 1053 to 1087 MHz band according to the CDMA and AMPS schemes, respectively.

Subsequently, the first mixer 31 has an RF frequency of 1930 to 1990 MHz band by the PCS scheme passed through the first RF SAW filter 23 and a PCS local of 2106 to 2174 MHz band input through the second switch 42. The frequency is mixed to output a receiving side IF frequency in the 183.6 MHz band, and the second mixer 32 divides the RF frequency of the 869 to 894 MHz band by the CDMA scheme passed through the second RF SAW filter 24 and the divider 43. -2) mixes the CDMA and AMPS local frequencies of the 1053 to 1087 MHz band and outputs the receiving IF frequency of the 183.6 MHz band, and the third mixer 33 passes through the second RF SAW filter 24. The receiver IF frequency in the 183.6 MHz band is output by mixing the RF frequencies in the 869 to 894 MHz band according to the AMPS method and the CDMA and AAMP local frequencies in the 1053 to 1087 MHz band output from the divider 43-2.

Thereafter, the first IF BPF 35 band-limits the receiving side IF frequency by the PCS scheme inputted through the first switch 34 or the receiving side IF frequency by the CDMA scheme, and passes the second IF BPF 36. ) Band-limits the receiving IF frequency by the AMPS method output from the third mixer 33.

Since the operation is the same as that described in FIG.

As described above, the present invention changes the IF frequency of the PCS method and the IF frequency of the CDMA and AMPS methods used on the receiving side of the mobile terminal for dual band or tree mode, and uses the PCS method on the transmitting side. By changing the IF frequency of CDMA and AMPS method differently and removing one of the three IF BPFs used at the receiving side, only two IF BPFs are used, and only one VCO is used as a multiplexer and divider are used. This reduces the number of components and the area they occupy, reducing component costs and simplifying circuit design.

In addition, by sharing one IF BPF for the 1.9GHz PCS scheme and the 800MHz CDMA scheme at the receiving side of the mobile communication terminal, it is possible to reduce interference with each other.

Claims (5)

delete In the transceiver of the mobile communication terminal for dual band / tree mode operating in accordance with the PCS method or CDMA, AMPS method, respectively, Frequency band where the receiving side IF frequency by PCS method and the receiving side IF frequency by CDMA and AMP method have the same frequency band, and the transmitting IF frequency by PCS method and the transmitting IF frequency by CDMA and AMPS method are different. Local frequency generator for generating CDMA, AMPS local frequency and PCS local frequency in order to have a, First and second LNA and RF SAW filters for low noise amplifying each noise frequency received through a diplexer, a PCS duplexer and a CDMA and AAMP duplexer, and removing noise; Receive the same band by mixing the PCS method and the CDMA, AMPS method and the PCS local frequency generated by the local frequency generator and the CDMA, AMPS local frequency respectively passed through the first and second RF SAW filters First to third mixers for outputting a side IF frequency; Band-limiting and passing the receiving side IF frequency by the PCS method and the CDMA method and the receiving side IF frequency by the AMPS method output from the third mixer through the switching operation The first and second IF BPFs, The PCS local frequency and the CDMA / AMPS local frequency and the PC-side IF frequency and the CDMA / AMPS transmission-side IF frequency inputted from the local frequency generator are switched through the switching operation according to the switching control signal of the MSM. IFT which mixes and outputs RF frequency by PCS method and RF frequency by CDMA and AMPS method, A third and fourth RF SAW filters and PAs for removing noise and amplifying power of the RF frequency by the PCS method and the RF frequency by the CDMA and AMPS signals output from the IFT; The local frequency generator, VDMA generating CDMA, AMPS local frequency, A switch for switching the local frequency generated by the VCO to output the second and third mixers; And a multiplexer for outputting the PCS local frequency by the PCS scheme to the first mixer by multiplying the CDMA and APS local frequencies inputted through the switch to the first mixer. In the transceiver of the mobile communication terminal for dual band / tree mode operating in accordance with the PCS method or CDMA, AMPS method, respectively, Frequency band where the receiving side IF frequency by PCS method and the receiving side IF frequency by CDMA and AMP method have the same frequency band, and the transmitting IF frequency by PCS method and the transmitting IF frequency by CDMA and AMPS method are different. Local frequency generator for generating CDMA, AMPS local frequency and PCS local frequency in order to have a, First and second LNA and RF SAW filters for low noise amplifying each noise frequency received through a diplexer, a PCS duplexer and a CDMA and AAMP duplexer, and removing noise; Receive the same band by mixing the PCS method and the CDMA, AMPS method and the PCS local frequency generated by the local frequency generator and the CDMA, AMPS local frequency respectively passed through the first and second RF SAW filters First to third mixers for outputting a side IF frequency; Band-limiting and passing the receiving side IF frequency by the PCS method and the CDMA method and the receiving side IF frequency by the AMPS method output from the third mixer through the switching operation The first and second IF BPFs, The PCS local frequency and the CDMA / AMPS local frequency and the PC-side IF frequency and the CDMA / AMPS transmission-side IF frequency inputted from the local frequency generator are switched through the switching operation according to the switching control signal of the MSM. IFT which mixes and outputs RF frequency by PCS method and RF frequency by CDMA and AMPS method, A third and fourth RF SAW filters and PAs for removing noise and amplifying power of the RF frequency by the PCS method and the RF frequency by the CDMA and AMPS signals output from the IFT; The local frequency generator, A VCO generating a PCS local frequency, A switch for switching the PCS local frequency generated in the VCO to output the first mixer; Dual band / tree mode, characterized in that the divider for dividing the PCS local frequency input through the switch by 1/2 to output the CDMA, AMPS local frequency by the CDMA, AMPS method to the second and third mixers. Transceiver for mobile communication terminal. The transceiver of claim 2 or 3, wherein the CDMA and AAMPs local frequencies are in the 1053 to 1087 MHz band and the PCS local frequencies are in the 2106 to 2174 MHz band. 4. The transceiver of claim 2 or 3, wherein the reception side IF frequency by the PCS scheme and the reception side IF frequency by the CDMA / AMPS scheme are 183.6 MHz bands. .