JP2003273676A - High frequency power control circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high frequency power control circuit which can be realized with simple configuration and further can be applied to frequencies from microwaves to quasi-millimeter waves as well. <P>SOLUTION: In the high frequency control circuit provided in an amplifier configured by providing bipolar transistors for a plurality of stages for controlling constant an output power outputted form the amplifier, the bipolar transistor has linearity between a collector current and an output power and between the collector current and a forward transmission gain, the output power of the amplifier detected on the basis of the collector current of the bipolar transistor on the final stage among the bipolar transistors is compared with a prescribed output power to be outputted by the amplifier, an a control means is provided for controlling the base current of the bipolar transistor on the first stage on the basis of the compared result. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a high frequency power control circuit used in a wireless communication device and a wire communication device.

[0002]

2. Description of the Related Art Conventionally, an output circuit is provided in an amplifier circuit for amplifying a signal input from an external signal source with a predetermined gain, and the output power output from the amplifier circuit is fed back to make the output power constant. There is a high frequency power control circuit to control. An example of such a high frequency power control circuit is the ALC circuit B shown in FIG. 8, which is the technique disclosed in Japanese Patent Laid-Open No. 11-186863. ALC above
In the circuit B, the input power supplied from the external signal source 100 is attenuated by the variable attenuator 210 by a predetermined value, and the bipolar transistors 221 provided in a plurality of stages (two stages in the figure as an example) are provided. It is supplied to the amplifying circuit X including. The output power amplified and output by the amplifier circuit X to a predetermined output power level is output by the duplexer 230 to 2
One output power is divided into a certain ratio, and one output power is supplied to the external load 300. In addition, the duplexer 2
The other output power of 30 is rectified by the detector 240 and becomes a detection voltage according to the input power. The wave detector 240
The detection voltage from is input to the loop filter 250,
It is preset in the loop filter 250 and compared with a predetermined target detection voltage V1 corresponding to the target output power. Based on the comparison result, when the detected voltage is lower, a control voltage that reduces the loss of the variable attenuator 210 is output, and conversely, when the detected voltage is higher, the loss of the variable attenuator 210 is reduced. A control voltage that increases is output. That is, when the output power supplied to the load 300 is large, the amount of attenuation of the variable attenuator 210 increases, so the supplied power decreases, and conversely, when the output power is small, the variable attenuator 2 increases.
The attenuation of 10 decreases and the supplied power increases. By constructing such a negative feedback circuit, the amplifier circuit X
It is possible to control the output power that is more output so as to always match the target output power.

[0003]

As described above, the conventionally known high frequency power control circuit includes a large number of the variable attenuator 210, the demultiplexer 230, the wave detector 240, or the loop filter 250. It is realized by using the components of. Each of the above components is a PI
It includes a large number of circuit elements such as N-diodes, capacitors, load resistors, etc., and its circuit configuration is complicated, so that it has the drawback of increasing the manufacturing cost or increasing the labor of adjustment. In addition, among the constituent elements, the variable attenuator 210 and the demultiplexer 230, in particular, have a large power loss due to their configurations, and the reduction in the gain of the amplifier circuit X due to the power loss cannot be avoided. . Furthermore, when the frequency handled by the amplifier circuit X is from microwave to quasi-millimeter wave or higher, the circuit element provided in each of the constituent elements becomes expensive, and in addition to the circuit design. With difficulty. As a result, in proportion to the frequency handled by the amplifier circuit X,
The manufacturing cost or design cost of the high frequency power control circuit increases. Therefore, the present invention has been made in view of the above problems, and an object thereof is a high frequency that can be realized by a simple configuration and can be applied to frequencies from microwave to quasi-millimeter wave or higher. It is to provide a power control circuit.

[0004]

In order to achieve the above object, the present invention comprises a plurality of stages of bipolar transistors, and sequentially amplifies and outputs an input signal input from a first stage bipolar transistor. In a high-frequency control circuit provided in an amplifier for controlling the output power output from the amplifier to be constant, the bipolar transistor has linearity between collector current and output power, and collector current and forward transfer gain. And comparing the output power of the amplifier detected based on the collector current of the last-stage bipolar transistor of the bipolar transistors with a predetermined output power to be output by the amplifier, Equipped with adjusting means for adjusting the base current of the first-stage bipolar transistor based on the comparison result. Be Te configured as a high-frequency power control circuit according to claim. With this configuration, it is possible to control the output power to a constant value without providing a detector or a variable attenuator, which is provided in a conventionally known high-frequency power control circuit and causes power loss. In addition to that, since it can be realized by a simple circuit configuration in which the number of parts is reduced, it is possible to reduce the production cost or the design cost.

Here, it is also possible that the high frequency power control circuit is provided with a temperature compensating means for compensating an output fluctuation with respect to a temperature change of the last-stage bipolar transistor. As a result, even if the collector current of the last-stage bipolar transistor fluctuates due to temperature changes, it becomes possible to control the output power output from the amplifier circuit to a constant level, and the output power output from the amplifying circuit can be kept constant. It is possible to realize a high-frequency power control circuit that can be operated without operation.

Further, a mode in which a plane circuit constituted by a strip line is inserted in the bias circuit provided in the bipolar transistor or a mode in which a choke coil is inserted can be considered. As a result, the impedance seen from the bipolar transistor at a specific frequency can be made sufficiently large, and the input signal to the bipolar transistor or the output signal from the transistor can be prevented from being wasted on the bias circuit side. It is possible to increase the gain of the amplifier circuit at a specific frequency.

Furthermore, it is conceivable that the first-stage bipolar transistor constitutes an oscillation circuit which oscillates by feeding back the collector output of the first-stage bipolar transistor. According to this mode, the amplifier outputs an output signal (oscillation signal) of a predetermined frequency from the oscillation circuit including the first-stage bipolar transistor, and outputs the output signal (oscillation signal) to the latter-stage bipolar transistor. The transistor constitutes an oscillator that amplifies with a predetermined gain. That is, the high frequency power control circuit according to the present invention is an output signal (oscillation signal) of a predetermined frequency.
Can also be applied to an oscillator for outputting

Here, it is conceivable that the frequency of the signal handled by the amplifier is from the microwave to the quasi-millimeter wave or higher.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments and examples of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention. It should be noted that the following embodiments and examples are examples embodying the present invention and do not limit the technical scope of the present invention. 1 is a block diagram showing a schematic configuration of a high frequency power control circuit according to a first embodiment of the present invention, and FIG. 2 is a schematic diagram of a high frequency power control circuit according to a second embodiment of the present invention. Block diagram, Figure 3
Is a block diagram showing a configuration of a grounded-emitter amplifier including a microwave circuit, FIG. 4 is a block diagram showing a configuration of a grounded-emitter amplifier including a choke coil, and FIG. 5 is a high-frequency power control circuit according to another embodiment of the present invention. FIG. 6 is a block diagram showing a schematic configuration, FIG. 6 is a graph showing a relationship between a transistor input power and a collector current, FIG. 7 is a graph showing a relationship between a transistor collector current and a gain, and FIG. 8 is a conventional high frequency power control circuit. It is a block diagram which shows a structure.

The high frequency power control circuit according to the present invention is shown in FIG.
As shown in, the high frequency power control circuit A1 is embodied. Here, first, the amplifier circuit X whose output is controlled by the high frequency power control circuit A1 will be described. The amplifier circuit X includes bipolar transistors (hereinafter abbreviated as transistors) 223 provided in two stages.
And a transistor 233. Here, a power supply voltage is applied to the collector of the transistor 223 via a load resistor 221a, and a predetermined current determined by the value of the bias resistor 222a is supplied to the base from the collector. A predetermined bias current is supplied to the transistor 223 by such a self-bias circuit. The transistor 233 is also supplied with a predetermined bias current by the same structure as the transistor 223. Since such a configuration is a configuration of a common grounded-emitter type amplifier circuit, detailed description thereof is omitted here. Further, in the amplifier circuit X, the input power supplied from the external signal source 100 passes through the capacitor 224a and the transistor 22 of the first stage.
3 bases are supplied. The input power supplied to the transistor 223 is amplified by the transistor 223 and supplied to the base of the transistor 233 in the subsequent stage via the capacitor 224b. The input power supplied to the transistor 233 is
It is further amplified by 33 and output to the external load 300 via the capacitor 224c. Thus, the output power output from the amplifier circuit X is
3, 233, the signals are sequentially amplified with a predetermined gain. However, the output power level of the output signal output from the amplifier circuit X varies depending on various factors such as variations in the input power supplied from the signal source 100, variations in the load capacity of the load 300, and the like. . Therefore, it is necessary to control the output power level of the output signal output from the amplifier circuit X to be constant by adjusting the gain in the amplifier circuit X according to the fluctuation of the output signal.

Here, in order to control the output signal output from the amplifier circuit X to be constant, it is necessary to detect the output power output from the amplifier circuit X. Therefore, first, a configuration for detecting the output power output from the amplifier circuit X will be considered. In this embodiment, attention is paid to the relationship between the collector current of the transistor 233 in the last stage and the output power of the transistor 233. Here, when the frequency handled by the amplifier circuit X to be controlled by the high frequency power control circuit A1 according to the present embodiment is a frequency from the microwave to the quasi-millimeter wave or more, the transistor to be applied to the amplifier circuit X is Some have linearity between collector current and output power. One example is N
It is a transistor (2SC5761) manufactured and sold by EC (NEC). Here, a graph showing changes in collector current and output power with respect to changes in input power of the transistor is shown in FIG. The graph shown in FIG. 6 is a characteristic curve of the transistor when the frequency of the input power is 2 GHz. From the graph, the collector current changes from 7 mA to 35 mA as the input power increases from -20 dBm to +5 dBm. And the output power increases from 0 dBm to +14 dBm at the same time.
It can be read that it is gradually increasing. Therefore, in the transistor, the input power and the output power can be specified by detecting the collector current. That is, in detecting the output power in the amplifier circuit X to which the transistor having such a property is applied, it is not necessary to provide the detector 240 as in the conventionally known high frequency power control circuit, and the collector current is detected. It can be substituted.

Further, in order to control the output signal output from the amplifier circuit X to be constant, it is necessary to arbitrarily adjust the gain of the amplifier circuit X. Therefore, next, consider a configuration in which the gain of the amplifier circuit X is arbitrarily adjusted. In this embodiment, attention is paid to the relationship between the collector current of the transistor 223 in the first stage and the forward transfer gain of the transistor 223. Here, similarly to the above, when the frequency handled by the amplifier circuit X to be controlled by the high frequency power control circuit A1 according to the present embodiment is a frequency from microwave to quasi-millimeter wave or more, it is applied to the amplifier circuit X. Some power transistors have a linear relationship between the collector current and the forward transfer gain. One example is N
Transistor manufactured and sold by EC (2SC576
1). Here, FIG. 7 is a graph showing changes in the forward transfer gain with respect to changes in the collector current of the transistor. The graph shown in FIG. 7 is a characteristic curve of the transistor when the input power frequency is 2 GHz. From the graph, as the collector current increases from 1 mA to 20 mA, the forward transfer gain | S21 _e | ² Is 8d
It can be read that it gradually increases from B to 18 dB. Therefore, in the transistor, the forward transfer gain can be arbitrarily adjusted by arbitrarily adjusting the collector current. That is, for adjusting the forward transfer gain (output power) in the amplifier circuit X to which the transistor having such a property is applied, it is not necessary to provide the variable attenuator 210 as in the conventionally known high frequency power control circuit. It can be substituted by adjusting the collector current.

Based on the characteristics of the transistor described above, the high frequency power control circuit A1 according to the present embodiment detects the output power of the amplifier circuit X detected based on the collector current of the transistor 233 in the last stage, and Amplifier circuit X
Loop for adjusting the collector current of the transistor 223 by comparing the collector current of the transistor 223 with the desired output power to be output, and adjusting the base current of the transistor 223 in the first stage based on the control signal obtained from the comparison result. A filter 250 (corresponding to an example of a comparison unit) is provided and configured. As a result, it becomes possible to control the output level of the output power output from the amplifier circuit X to a constant level with a simple configuration having a smaller number of parts than the conventionally known high frequency power control circuit. The loop filter 250 is
As shown in FIG. 1, it is composed of a two-stage operational amplifier. Here, since the collector current of the transistor 233 passes through the load resistor 221b, a voltage proportional to the collector current is generated at both ends of the load resistor 221, and this voltage passes through the load resistor 225a and the load resistor 253a. It is input to the inverting input terminal of the operational amplifier 251. On the other hand, the reference power V1 corresponding to the output power to be output from the amplification circuit X from the reference voltage generator (not shown) is input to the non-inverting input terminal via the load resistor 254. That is, the operational amplifier 251 includes the transistor 233.
The error signal obtained by differentially amplifying the voltage proportional to the collector current of the above and the reference voltage V1 is output to the operational amplifier 252 in the subsequent stage. In addition, the operational amplifier 25
The error signal from the operational amplifier 251 is input to the inverting input terminal of No. 2 via the load resistor 253, and the non-inverting input terminal is grounded. That is, the operational amplifier 252 is
The load resistor 225 supplies the control voltage obtained by subjecting the error signal input from the operational amplifier 251 to anti-phase amplification.
It is output to the transistor 223 via b. Accordingly, the loop filter 250 lowers the control voltage when the voltage proportional to the collector current of the transistor 233 input to the loop filter 250 is higher than the reference power V1, and raises the control voltage when it is lower. Calculate. The control voltage obtained by this logical operation is applied to the transistor 223 via the load resistor 225b.
Since it is input to the base of the transistor 223, the current flowing into the base of the transistor 223 can be increased or decreased according to the increase or decrease of the control voltage. Here, the transistor 22
The base current Ib of No. 3 and the collector current Ic have a relationship as shown in the following Expression 1. Ic = Ib × β (Equation 1) where β is the current amplification factor of the transistor. Due to this relationship, the collector current of the transistor 223 can be increased or decreased according to the increase or decrease of the control voltage from the loop filter 250, and the forward transfer gain can be increased or decreased. As described above, in the high frequency power control circuit A1 according to the embodiment of the present invention, the output power can be controlled to be constant without providing the detector or the variable attenuator that causes the power loss. It is possible to reduce the number of parts, which has an effect of reducing the production cost or the design cost.

By the way, since the current amplification factor β of the transistor in the above equation 1 changes with temperature,
Even when operated under the same bias condition, the collector current of the transistor varies with temperature. Therefore, in the above embodiment, the transistor 233 changes due to temperature change.
If the collector current fluctuates, the output power detected based on the collector current is inaccurate.
Therefore, FIG. 2 is used for an embodiment in which a temperature compensating transistor 243 (corresponding to an example of temperature compensating means) for keeping the output power output from the amplifier circuit X constant even when the temperature changes is used. Explain. In FIG. 2, the voltage from the temperature compensating transistor 243 is supplied to the loop filter 250 via the load resistor 225c. Here, the temperature compensating transistor 2
Reference numeral 43 denotes a transistor which is thermally coupled to the transistor 233 and whose base is grounded by a capacitor 226 in terms of high frequency. Further, the transistor 233 and the temperature compensating transistor 243 are adjusted so that the same collector current flows when there is no input signal from the signal source. Therefore, the collector current of the temperature compensating transistor 243 has a predetermined current value that depends only on the temperature, and further, the variation amount of the current value with respect to the temperature change depends on the temperature change of the collector current of the transistor 233. It becomes the same value as the fluctuation amount for. Therefore, in this embodiment, the temperature compensating transistor 243 is used.
The voltage corresponding to the collector current of the transistor 233 is input to the non-inverting input terminal of the operational amplifier 251 via the load resistor 255, so that the transistor 233 caused by the temperature change is generated.
It is possible to correct the reference electric power V1 corresponding to the output electric power to be output by the amplifier circuit X by the variation amount of the collector current. As a result, even when the collector current of the transistor 233 fluctuates due to temperature change, the output power output from the amplifier circuit X can be controlled to be constant, and the amplifier circuit can be operated regardless of the temperature of the surrounding environment. The high frequency power control circuit A2 is capable of controlling the output power of X with high accuracy.

Here, in the situation where a general amplifier circuit X is used, the frequency of the input power supplied from the signal source 100 is known, and further, the frequency of the input power to be amplified by the amplifier circuit X is known. Frequencies are often specified. In that case, by inserting a microwave circuit or a choke coil between the base and collector of the transistors 223 and 224 and the bias circuit, the gain at a specific frequency can be increased. FIG. 3 shows an embodiment in which a plane circuit 229 using a strip line having a line length of 1/4 with respect to the wavelength (λ) of the input power input is inserted in a bias circuit for the base and collector of the transistor. ing. Such a planar circuit 229
By inserting, the impedance seen from the transistor 223 can be made sufficiently large at a specific frequency, most of the input signal to the transistor can be input to the base side, and most of the output signal of the transistor can be input. Can be supplied to the load side, the input signal can be prevented from being wasted on the bias circuit side, and the gain of the amplifier circuit X can be increased. FIG. 4 shows an embodiment in which the choke coil 229 is used. Here, since the impedance of the choke coil 229 becomes extremely large at a high frequency, by inserting such a choke coil 229, the impedance seen from the transistor 223 in a high frequency signal can be made extremely large. As in the case of the planar circuit described above, the gain of the amplifier circuit X can be increased at a specific frequency.

[0016]

[Embodiment] In the embodiment described above, the case where the output power of the amplifier circuit X is controlled by the high frequency power control circuit A to a constant value has been described. However, the transistor 223 at the first stage feeds back the output signal of the transistor 223. Output power (oscillation signal) of the oscillation circuit that constitutes an oscillation circuit that oscillates by using the input signal as an input signal, and the transistor 233 in the subsequent stage functions as a buffer amplifier for amplifying the oscillation signal from the transistor.
The same effect can be obtained when constant control is performed. FIG. 5 shows an example in which the high frequency power control circuit A3 according to the embodiment of the present invention is applied to the oscillator circuit Y. First,
A schematic configuration of the oscillator circuit Y will be described. In the oscillator circuit Y, a part of the collector output of the transistor 223 is passed through the capacitor 224 to, for example, LC
Resonator 40 comprising a resonator and a capacitor
Sent to 0. Here, according to the setting, the resonator 400 passes a signal of a specific frequency f with almost no attenuation,
Since other frequencies are greatly attenuated, only the signal of the specific frequency f is selected and the capacitor 2
It is possible to feed back to the transistor 223 via 24. With such a configuration, the oscillation circuit Y
Then, after amplifying an oscillation signal according to the number of loop gains of a feedback loop constituted by the transistor 223 and the resonator 400, the oscillation signal is further amplified by the transistor 233 with a predetermined gain and output. Is. Since such a configuration is a general oscillation circuit, detailed description thereof is omitted here. In order to control the output power (oscillation signal) of the oscillator circuit Y to be constant, the high frequency power control circuit A3 can be applied. That is, as in the case of applying to the amplifier circuit X described above, the voltage corresponding to the output power (oscillation signal) is the reference voltage V2 corresponding to the target output power (oscillation signal) to be oscillated by the oscillation circuit Y. When it is smaller, the output of the loop filter 250 is increased and the base current supplied to the transistor 223 through the load resistor 225 is increased, so that the forward transfer gain of the transistor 223 can be increased. This increases the loop gain of the loop formed by the transistor 223 and the resonator 400, so that the output power level (oscillation amplitude) of the output power (oscillation signal) can be increased.
On the contrary, when the voltage according to the output power (oscillation signal) is larger than the reference voltage V2 according to the target output power (oscillation signal), the output of the loop filter 250 is decreased, and the load resistor 225 causes the transistor to pass through. By reducing the base current supplied to 223, the transistor 2
The forward transfer gain of 23 can be reduced. This reduces the loop gain of the loop formed by the transistor 223 and the resonator 400, so that the output power level (oscillation amplitude) of the output power (oscillation signal) can be reduced. In this way, the transistor 2
The output power level (oscillation amplitude) of the output power (oscillation signal) of the buffer amplifier composed of 33 is compared with the reference voltage corresponding to the predetermined output power (oscillation signal) to be oscillated by the oscillation circuit Y. Accordingly, the output power (oscillation signal) output from the oscillation circuit Y can be controlled to be constant by controlling the loop gain of the loop formed by the transistor 223 and the resonator 400.

Although the number of transistor stages is two in the above embodiments and examples, the number of transistor stages may be three or more depending on the gain required for the amplifier circuit X or the oscillator circuit Y. It is possible. In that case, all the amplifiers do not have to be bipolar transistor amplifiers, and an FET amplifier or the like may be used as an intermediate amplifier.

Furthermore, in the above-described embodiments and examples, the self-bias circuit is used as the bias circuit of the transistor, but it may be a fixed bias circuit. In this case, the bias resistor 222 may be inserted between the base of the transistor 223 (233) and the power supply. The bias circuits of all the transistors do not have to be the same, and different bias circuits can be used for each transistor as needed.

[0019]

As described above, the present invention is configured to include bipolar transistors provided in a plurality of stages,
In a high-frequency control circuit provided in an amplifier that sequentially amplifies and outputs an input signal input from a first-stage bipolar transistor, and in which the bipolar transistor has a collector current and a collector current, The output power of the amplifier, which has linearity between the output power and the collector current and the forward transfer gain, and is detected based on the collector current of the last bipolar transistor among the bipolar transistors. A high frequency power control circuit comprising an adjusting means for comparing a predetermined output power to be output by the amplifier and adjusting the base current of the first-stage bipolar transistor based on the comparison result. Configured as. With this configuration, it is possible to control the output power to a constant value without providing a detector or a variable attenuator, which is provided in a conventionally known high-frequency power control circuit and causes power loss. In addition to that, since it can be realized by a simple circuit configuration in which the number of parts is reduced, it is possible to reduce the production cost or the design cost.

Here, it is also conceivable that the high frequency power control circuit includes a temperature compensating means for compensating an output fluctuation with respect to a temperature change of the last-stage bipolar transistor. As a result, even if the collector current of the last-stage bipolar transistor fluctuates due to temperature changes, it becomes possible to control the output power output from the amplifier circuit to a constant level, and the output power output from the amplifying circuit can be kept constant. It is possible to realize a high-frequency power control circuit that can be operated without operation.

Further, a mode in which a plane circuit constituted by a strip line is inserted into the bias circuit provided in the bipolar transistor or a form in which a choke coil is inserted can be considered. As a result, the impedance seen from the bipolar transistor at a specific frequency can be made sufficiently large, and the input signal to the bipolar transistor or the output signal from the transistor can be prevented from being wasted on the bias circuit side. It is possible to increase the gain of the amplifier circuit at a specific frequency.

Further, it is conceivable that the first-stage bipolar transistor constitutes an oscillation circuit which oscillates by feeding back the collector output of the first-stage bipolar transistor. According to this mode, the amplifier outputs an output signal (oscillation signal) of a predetermined frequency from the oscillation circuit including the first-stage bipolar transistor, and outputs the output signal (oscillation signal) to the latter-stage bipolar transistor. The transistor constitutes an oscillator that amplifies with a predetermined gain. That is, the high frequency power control circuit according to the present invention is an output signal (oscillation signal) of a predetermined frequency.
Can also be applied to an oscillator for outputting

Here, it is conceivable that the frequency of the signal handled by the amplifier is from the microwave to the quasi-millimeter wave or higher.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a high frequency power control circuit according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a high frequency power control circuit according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a grounded-emitter amplifier including a microwave circuit.

FIG. 4 is a block diagram showing a configuration of a grounded-emitter amplifier including a choke coil.

FIG. 5 is a block diagram showing a schematic configuration of a high frequency power control circuit according to another embodiment of the present invention.

FIG. 6 is a graph showing the relationship between input power and collector current of a transistor.

FIG. 7 is a graph showing the relationship between the collector current and the gain of a transistor.

FIG. 8 is a block diagram showing a configuration of a high frequency power control circuit according to a conventional technique.

[Explanation of symbols] A: High frequency power control circuit B: High frequency power control circuit X ... Amplification circuit Y ... Oscillation circuit 100 ... Signal source 200 ... High frequency power control circuit 300 ... load 210 ... Variable attenuator 230 ... duplexer 240 ... Detector 250 ... Loop filter 221 ... resistance 222 ... resistance 223 ... Transistor 224 ... Capacitor 225 ... resistance 226 ... Capacitor 233 ... Transistor 243 ... Transistor for temperature compensation 228 ... Microwave planar circuit 229 ... Choke coil 400 ... Resonator

Continued front page    F term (reference) 5J067 AA01 AA04 AA41 CA02 CA61                       CA81 FA10 FA17 HA02 HA25                       HA29 HA33 KA01 KA12 KA13                       KA23 KA32 KA41 KA55 KA68                       KS01 KS25 MA11 MA21 QS02                       SA13                 5J090 AA01 AA04 AA41 CA02 CA11                       CA61 CA81 CN01 FA10 FA17                       FN10 FN12 HA02 HA25 HA29                       HA33 HN16 HN23 KA01 KA12                       KA17 KA68 MA08 MA11 MA21                       SA13                 5J100 JA01 JA09 LA01 MA00                 5J500 AA01 AA04 AA41 AC02 AC11                       AC61 AC81 AF10 AF17 AH02                       AH25 AH29 AH33 AK01 AK12                       AK17 AK68 AM08 AM11 AM21                       AS13 NC01 NF10 NF12 NH16                       NH23

Claims (6)

[Claims] 1. An amplifier configured to include a plurality of stages of bipolar transistors, which is provided in an amplifier for sequentially amplifying and outputting an input signal input from the first stage bipolar transistor, and a constant output power output from the amplifier. In the high-frequency control circuit for controlling, the bipolar transistor has linearity between the collector current and the output power, and the collector current and the forward transfer gain. The output power of the amplifier detected based on the collector current of the bipolar transistor is compared with a predetermined output power to be output by the amplifier, and based on the comparison result,
A high frequency power control circuit comprising an adjusting means for adjusting a base current of the first-stage bipolar transistor. 2. The high frequency power control circuit according to claim 1, wherein the high frequency power control circuit comprises a temperature compensating means for compensating for an output fluctuation with respect to a temperature change of the last-stage bipolar transistor. 3. The high frequency power control circuit according to claim 1, wherein a planar circuit constituted by a strip line is inserted in a bias circuit provided in the bipolar transistor. 4. The high frequency power control circuit according to claim 1, wherein a choke coil is inserted in a bias circuit provided in the bipolar transistor. 5. The first-stage bipolar transistor comprises:
The high frequency power control circuit according to any one of claims 1 to 4, comprising an oscillation circuit that oscillates by feeding back a collector output of the first-stage bipolar transistor. 6. The high frequency power control circuit according to claim 1, wherein the frequency of the signal handled by the amplifier is from microwave to quasi-millimeter wave or higher.