JPH04310867A - High frequency power measuring device - Google Patents

Abstract

PURPOSE:To obtain an inexpensive high frequency power measuring device capable of being relatively easily repaired even when damage occurs and capable of monitoring high frequency power even during the transmission to a utilization apparatus. CONSTITUTION:A solid plate-shaped dielectric layer 11 is provided on the waveguide 2 from a high frequency oscillator 5 and a cooling medium is circulated to the peripheral edge part of the solid plate-shaped dielectric layer 11 by a cooling medium circulating device 4. By detecting the temp. rise of the cooling medium by a temp. measuring device 6, the temp. rise due to the thermalization quantity of high frequency power is detected to measure high frequency power.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency power measuring instrument.

0002

2. Description of the Related Art FIG.
1 is a configuration diagram showing a high-frequency simulated load, which is a type of conventional high-frequency power measuring device disclosed in the above publication. In the figure, 1
is a hollow triangular pyramid made of ceramic such as alumina, 2 is a waveguide, 3 is a cooling water jacket, 4 is a cooling water circulator, and 5 is a high frequency oscillator.

The high-frequency power generated by the high-frequency oscillator 5 and propagating through the waveguide 2 loses a part of it when it passes through the ceramic hollow triangular pyramid 1 installed in the middle, and the temperature of the ceramic 1 increases. to rise. The transmitted high frequency waves are absorbed by the cooling water 3 while propagating through the cooling water 3. Cooling water 3 is made to flow through a cooling water circulator 4 to cool ceramic 1 . Based on the temperature rise of the cooling water 3, the power absorbed in the high frequency simulated load is converted to calculate the high frequency propagation power.

0004

[Problems to be Solved by the Invention] In the conventional high-frequency power measuring device as described above, as the propagation power increases, the temperature of the ceramic 1 and its creeping layer increases, resulting in thermal stress fracture of the ceramic 1. . Furthermore, there is a risk that the cooling water 3 will bump due to absorption of high-frequency power, causing shock damage to the ceramic 1. For this reason, it is necessary to reduce the power density of heat generation by reducing the apex angle of the triangular pyramid to expand the heat generation area, and the ceramic 1 is required to be integral and larger. There was a problem.

[0005]Furthermore, conventional high-frequency power measuring instruments are inserted into the transmission circuit in a manner that blocks the transmission of high-frequency waves to high-frequency devices, and therefore cannot be used to measure transmitted power while high-frequency waves are being used. For this reason, conventionally, directional couplers have been used to monitor transmitted power, but as transmission waves become larger in power and frequency, it becomes necessary to design directional couplers and accurately monitor transmitted power. There was also the problem that it became difficult.

The present invention has been made to solve these problems, and is inexpensive, can be repaired relatively easily even if damage occurs, and can be used while transmitting high frequency power to the equipment that uses it. The aim is to obtain a high-frequency power measuring device that can monitor transmitted power.

[0007]

[Means for Solving the Problems] A high-frequency power measuring device according to the present invention includes a solid plate-like dielectric layer provided in a high-frequency waveguide, a coolant circulator that cools the dielectric layer by circulating a coolant, and a layer The system is equipped with a temperature measuring device that detects the temperature rise due to the amount of heat generated by high-frequency power.

[0008] In addition, a coolant layer is formed in the high-frequency waveguide by a coolant that cools the surface of the solid plate-like dielectric layer provided in the high-frequency waveguide, and the temperature measuring device is connected to the solid plate-like dielectric layer and the coolant layer. This system detects the temperature rise due to the amount of heat generated by high-frequency power.

[0009]

[Operation] The high frequency power measuring device configured as described above thermalizes and attenuates the high frequency waves by transmitting them through a ceramic flat plate or a ceramic flat plate and a refrigerant layer that cools it. Calculate the high frequency power from the temperature rise. Therefore, it is inexpensive because it uses a small ceramic disc with the same size as the cross section of the waveguide, and it is possible to install multiple solid plate dielectric layers in a high-frequency waveguide and measure with one solid plate dielectric layer. It is also possible to reduce the amount of power. Furthermore, even if damage occurs, it can be repaired by replacing the ceramic plate, and furthermore, the transmitted power can be monitored while the high-frequency power is being transmitted to the device that uses it.

0010

[Example] Example 1. FIG. 1 is a block diagram showing a high frequency power measuring device according to an embodiment of the present invention. In the figure, 2
is a waveguide made of copper and constitutes a high frequency waveguide, 3 is a cooling water jacket, 4 is a cooling water circulator, 5 is a high frequency oscillator, 6 is a cooling water temperature measuring device, and 7 is provided at both ends. It is a flange. Further, 10 is a first high-frequency attenuator, 11 is a solid plate-like dielectric layer, for example, a circular ceramic plate, 20 is a second high-frequency attenuator, and 30 is a large number of high-frequency attenuators. The devices 10, 20, and 30 are fixed to the waveguide 2 by the flange 7 and installed in the high-frequency waveguide. Note that in this example, the ceramic plate 1
Water is used as a refrigerant to cool the

FIG. 2 is a block diagram showing one unit of a high frequency attenuator according to an embodiment of the present invention. In the figure, 9
is an arrow indicating the direction of incidence of high frequency waves.

The high frequency wave generated by the high frequency generator 5 and propagating through the waveguide 2 is guided to a first high frequency attenuator 10 provided in the middle. When passing through the ceramic plate 11, some of it is lost and the temperature of the ceramic plate 11 increases. The cooling water 3 is in contact with the ceramic plate 11 at the peripheral edge,
The temperature rise of the ceramic plate 11 is absorbed. By measuring the temperature rise of the cooling water 3 with the cooling water temperature measuring device 6,
The power absorbed in the high frequency simulated load is converted, and the high frequency propagation power can be calculated.

In this embodiment, a plurality of high-frequency attenuators are used, and the high-frequency propagation power can be calculated by calculating the sum of the outputs from all the cooling water temperature detectors.

The high-frequency attenuators 10, 20, and 30 that constitute the high-frequency power measuring device of the first embodiment are individually based on the same principle as a conventional high-frequency window that transmits high frequencies. The high-frequency window is configured to have a ceramic plate or a surface-cooled refrigerant layer with low high-frequency loss in order to suppress attenuation. The ceramic, refrigerant material, and thickness of the unit high-frequency attenuator constituting the high-frequency power measuring device in this embodiment are selected so as to generate high-frequency loss to the extent that it can maintain its integrity. The high frequency waves are thermalized in the process of passing through a plurality of units of high frequency attenuators.

The loss Q per unit volume when a high frequency wave having a frequency f and an electric field strength E is incident on a medium having a dielectric constant ε and a dielectric loss coefficient tan δ is evaluated by the following equation 1.

[0016]

[Math 1]

Furthermore, in order to avoid impedance mismatch on the surface of the ceramic plate 1, the thickness t of the ceramic plate 1 is
is selected to have a thickness that does not cause stress failure, taking into account the limitations of Equation 2 below.

[0018]

[Math 2]

In Equation 2, β is the propagation constant of the ceramic plate 1,
n is an integer. Conventionally, a high frequency attenuator having a structure like this embodiment has been used as a high frequency window. However, in order to function as a high-frequency window, the ceramic plate must have a structure with low high-frequency loss in order to suppress attenuation. That is, a medium is selected that can reduce the loss Q, and therefore a medium that can also reduce the layer thickness t. On the other hand, in the high frequency attenuators 10, 20, and 30 according to the first embodiment of the present invention, a medium having a large loss Q within a cooling range is used. As the material for the dielectric layer 1, a ceramic disk is commonly used in consideration of thermal and mechanical conditions.

According to this embodiment, the high frequency attenuator can be obtained by combining the high frequency attenuators of the same standard using small disc-shaped ceramic plates, and furthermore, since the high frequency attenuator only needs to absorb a part of the transmitted power, , the device can be provided at low cost. Further, since the unit high frequency attenuator can be easily attached to the high frequency waveguide 2 by the flange 7, it is easy to repair it when it is damaged.

Furthermore, since the unit high-frequency attenuator is a high-frequency attenuator that has the function of a conventional high-frequency window, if it is inserted in the middle of transmitting high-frequency power to the device that uses it, the high-frequency power can be Needless to say, the transmitted power can be monitored even during transmission to the device being used. When monitoring transmission power, it is sufficient to configure one high-frequency attenuator. By making the refrigerant flow rate variable and compensating for temperature rise and fall at low output, accuracy at low output can be improved compared to monitoring with a high-frequency window.

Furthermore, even if the high-frequency attenuator on the inner side of the high-frequency attenuator on the high-frequency oscillator 5 side is damaged, the effect on the high-frequency oscillator 5 side is reduced.

Example 2. In Example 1, water was used to cool the peripheral edge of the solid plate dielectric layer 11 made of a ceramic plate. A double disk type high frequency attenuator may be constructed in which the formed layer attenuates high frequencies. FIG. 3 shows the configuration of a high frequency power measuring device according to the second embodiment. FIG. 4 is a configuration diagram showing a double disk type high frequency attenuator according to the second embodiment. In the figure, reference numeral 8 denotes a coolant layer, and 11a and 11b indicate solid plate-like dielectric layers, such as disk-shaped ceramic plates.
It has a configuration in which there is an intervention. Further, 12 is a refrigerant jacket.

The operation in this second embodiment is almost the same as that in the first embodiment, but the high frequency is also absorbed by the refrigerant layer 8. That is, the high frequency wave generated by the high frequency oscillator 5 and propagating through the waveguide 2 is guided to the first high frequency attenuator 10 installed in the middle. Ceramic plate 11a, coolant layer 8
, when passing through the ceramic plate 11b, some of it is lost and their temperature increases. Coolant layer 8 is ceramic plate 1
1a and 1b are surface cooled, and the temperature increase is also absorbed. By measuring the temperature rise of the refrigerant 12 with the temperature measuring device 6, the power absorbed during the high frequency simulated load is converted,
High frequency propagation power can be calculated.

In this example, the loss Q is evaluated in the same manner as in Example 1, with the thickness of the coolant layer 8 being t' and the propagation constant being β.
', then the thickness t' is selected using Equation 3, where n' is an integer. As the dielectric material, a ceramic disk is commonly used in consideration of thermal and mechanical conditions.

[0026]

[Math 3]

[0027] The output characteristics of a high-frequency oscillator are affected by the voltage standing wave ratio (VSWR) of the transmission circuit, and if this value is high and the reflected wave is large, there is a risk of causing discharge in the transmission circuit. There is. By inserting a unit of high-frequency attenuator into the transmission circuit, the VSWR changes each time. Since the thickness t' of the double-disk type coolant layer 8 can be adjusted, it is possible to optimize the VSWR for the oscillator 5, including the reflected waves from the subsequent transmission circuit system.

Furthermore, in this embodiment, by making the refrigerant flow rate variable and compensating for temperature rise and fall at low output, accuracy at low output can be improved. In Example 1, if the temperature rise of the ceramic plate 11 is small and power measurement is difficult, a high frequency power measuring device that absorbs high frequency waves in the coolant layer 8 is effective. That is, depending on the oscillation mode, the single-disk type high-frequency power measuring device of Example 1, which uses a low-loss material for the high-frequency oscillator, is effective, and when the temperature rise of the cooling water is small and power measurement is difficult. The double-disc type high-frequency power measuring device shown in Example 2 is effective for this purpose.

In addition, when the waveguide of the transmission circuit is made into a vacuum, the single disk type shown in Example 1 is installed on the high frequency oscillator 5 side, and the double disk type shown in Example 2 is installed on the subsequent stage side. This can be expected to have the effect of reducing the spread of the influence on the high frequency oscillator 5 side due to leakage of refrigerant into the waveguide at the time of breakage.

[0030]

As described above, according to the present invention, there is provided a solid plate dielectric layer provided in a high frequency waveguide, a refrigerant circulator that cools the dielectric layer by circulating a refrigerant, and a high frequency power supply in the layer. Equipped with a temperature measuring device that detects the temperature rise due to the amount of heatization of
The present invention has the advantage of providing a high-frequency power measuring instrument that is easy to repair in the event of damage and that can monitor the transmitted power even while the high-frequency power is being transmitted to the device that uses it.

[0031] Furthermore, a coolant layer is formed in the high-frequency waveguide by a coolant that cools the surface of the solid plate-like dielectric layer provided in the high-frequency waveguide, and the temperature measuring device is connected to the solid plate-like dielectric layer and the coolant layer. Since the temperature rise due to the amount of thermalization of the high-frequency power is detected at , there is an effect that a high-frequency power measuring instrument that can improve accuracy at low outputs can be obtained.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing a high frequency power measuring device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a high frequency attenuator related to the high frequency power measuring device according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram showing a high frequency power measuring device according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram showing a high frequency attenuator related to a high frequency power measuring device according to a second embodiment of the present invention.

FIG. 5 is a configuration diagram showing a conventional high frequency power measuring device.

[Explanation of symbols]

2 Waveguide 4 Refrigerant circulator 5 High frequency oscillator 6 Temperature measuring device 8 Refrigerant layer 11 Solid plate dielectric layer

Claims (2)

[Claims] Claim 1: A solid plate-shaped dielectric layer provided in a high-frequency waveguide, a refrigerant circulator that circulates a refrigerant to cool the dielectric layer, and a temperature rise due to the amount of heat generated by the high-frequency power in the layer. A high frequency power measuring device characterized by being equipped with a temperature measuring device for detecting temperature. 2. A coolant layer is formed in the high-frequency waveguide by a coolant that cools the surface of the solid plate-like dielectric layer provided in the high-frequency waveguide, and the temperature measuring device is connected to the solid plate-like dielectric layer and the above-mentioned solid plate-like dielectric layer. 2. The high-frequency power measuring device according to claim 1, wherein the high-frequency power measuring device detects a temperature rise due to the amount of heat generated by the high-frequency power in the refrigerant layer.