JP2020022021A - Current adjustment method, current adjustment device, and adaptive array antenna - Google Patents

Abstract

To adjust a current flowing through an amplifier with high accuracy.SOLUTION: When a current flows only in a reference current circuit (600), a current detection circuit (400) detects the current flowing on the reference current circuit as a first reference current, and converts the value of the first reference current into a first reference voltage. When the first reference current flows through the reference current circuit and an amplifier (100), respectively, the current detection circuit converts the current flowing through the reference current circuit and the amplifier into a second reference voltage. When a current flows only on the amplifier, the current flowing only to the amplifier is adjusted so that the output voltage from the current detection circuit is the second reference voltage.SELECTED DRAWING: Figure 1

Description

  The technology disclosed in the present specification relates to a current adjustment method, a current adjustment device, and an adaptive array antenna.

  2. Description of the Related Art In mobile communication devices in recent years, in order to increase the communication speed, widening of a signal band, application of a multi-antenna technology, and the like are being promoted.

  In the fifth generation mobile communication system, in order to further improve the communication speed, beamforming is performed using an adaptive array antenna (ie, AAA) having a high directivity and composed of 100 or more antenna elements. The application of multiple-input and multiple-output (MIMO) technology (or massive MIMO) technology, which enables interference avoidance by the above and multiple users to connect simultaneously, is being studied.

  In the adaptive array antenna, the weighting of each antenna element is adaptively controlled according to the propagation environment. By electrically changing the directivity of the antenna, the main lobe of the antenna directivity is directed to the desired desired wave, and a null point (that is, the directivity pattern of the antenna falls in the direction of the unnecessary interference wave). And remove the interference wave.

  By controlling in this way, it is possible to improve the SIR (signal to interference power ratio) ratio of the desired signal power to the interference signal power. Then, the frequency use efficiency can be improved, and as a result, the capacity of the system can be increased.

  In order to control the main lobe and the side lobe of the adaptive array antenna with high accuracy, it is desirable that the characteristics of the individual antenna elements match. To achieve this, it is necessary to adjust the gain characteristics and the saturation characteristics of the amplifiers connected to each antenna element.

The gain characteristics and the saturation characteristics of the amplifier depend on the value of the drain current _Idq in a state where a high-frequency signal is not input (that is, in a non-input state). The value of the drain current _Idq can be adjusted by controlling the gate bias voltage of the amplifier.

It is known that, in an amplifier used for a millimeter wave or the like, a gate bias voltage having a desired value of a drain current _Idq differs for each amplifier.

Therefore, in the adjustment of the amplifier, a procedure of changing the gate bias voltage while measuring the drain current _Idq in the non-input state is taken. Specifically, a drain current I _dq flowing through each amplifier is measured by a current sensor of a shunt resistance element or a non-contact element (for example, a Hall element), and the drain current I _dq becomes a desired value. There is a method of setting the gate bias voltage of each amplifier (for example, see Patent Document 1).

A current sensor using a Hall element theoretically outputs an output voltage V _meas proportional to the measured current (that is, the input current I _IN ) according to the following equation (1).

Here, in the equation (1), a is the sensitivity and is a proportional constant between the input current I _IN and the output voltage V _meas . V _offset is an offset value of the output voltage.

Depending on the individual difference of the current sensor and the mounting state of the current sensor, the sensitivity a and the value of V _offset vary. Further, according to the measurement by the inventor, a long-period noise of several tens of seconds is mixed in the output voltage of the current sensor. Due to these factors, the accuracy of measuring the drain current using the current sensor decreases.

Japanese Patent No. 4429347

Sensitivity and V _offset are determined by measuring currents from two or more current sources having different current values, and the drain is determined using the determined sensitivity, V _offset , and the relationship shown in equation (1). When adjusting the current, it is not possible to absorb variations in the sensitivity a and V _offset of the individual current sensors with respect to equation (1). Therefore, an error occurs in the adjustment of the drain current.

  If the circuit configuration is such that the current flowing through the reference circuit is equal to the value of the drain current to be adjusted in order to accurately adjust the drain current, prepare a reference circuit for each condition of the drain current to be adjusted. And the circuit scale of the current sensor becomes large.

  The technology disclosed in this specification has been made to solve the problems described above, and has as its object to provide a technology for adjusting the current flowing through an amplifier with high accuracy. Things.

  A first aspect of the technology disclosed in the present specification is that at least one amplifier through which a current for performing amplification flows is connected, and the current is connected in parallel with the amplifier, and the current flows in parallel with the current flowing through the amplifier. In a circuit configuration including a flowing reference current circuit, and a current detection circuit that detects the current flowing through the amplifier and the reference current circuit, and converts the value of the current into an output voltage, only the reference current circuit When a current is passed, the current detection circuit detects the current flowing in the reference current circuit as a first reference current, and converts the value of the first reference current into a first reference voltage. When the first reference current flows through the reference current circuit and the amplifier, the current detection circuit determines the value of the first reference current flowing through the reference current circuit and the amplifier. And the value of the first reference current is converted into a second reference voltage, and when the current flows only through the amplifier, the output voltage of the current detection circuit becomes the second reference voltage. Thus, the current flowing only to the amplifier is adjusted.

  According to a second aspect of the technology disclosed in the present specification, an amplifier through which a current for performing amplification flows is connected to the amplifier in parallel, and a current flows in parallel with the current flowing through the amplifier. A reference current circuit, a current detection circuit that detects the current flowing through the amplifier and the reference current circuit, and converts the value of the current into an output voltage, and adjusts the current flowing through the amplifier and the reference current circuit. And an adjusting unit, wherein when the adjusting unit causes the current to flow only to the reference current circuit, the current detection circuit detects the current flowing to the reference current circuit as a first reference current, and Converting the value of the first reference current into a first reference voltage, and when the first reference current is passed through the reference current circuit and the amplifier by the adjustment unit, The current detection circuit converts the value of the first reference current flowing through the reference current circuit and the value of the first reference current flowing through the amplifier into a second reference voltage, and the adjustment unit includes: The current flowing only through the amplifier is adjusted so that the output voltage of the current detection circuit becomes the second reference voltage when the current flows only through the amplifier.

  A third aspect of the technology disclosed in the specification of the present application includes the above-described current adjusting device.

  A first aspect of the technology disclosed in the present specification is that at least one amplifier through which a current for performing amplification flows is connected, and the current is connected in parallel with the amplifier, and the current flows in parallel with the current flowing through the amplifier. In a circuit configuration including a flowing reference current circuit, and a current detection circuit that detects the current flowing through the amplifier and the reference current circuit, and converts the value of the current into an output voltage, only the reference current circuit When a current is passed, the current detection circuit detects the current flowing in the reference current circuit as a first reference current, and converts the value of the first reference current into a first reference voltage. When the first reference current flows through the reference current circuit and the amplifier, the current detection circuit determines the value of the first reference current flowing through the reference current circuit and the amplifier. And the value of the first reference current is converted into a second reference voltage, and when the current flows only through the amplifier, the output voltage of the current detection circuit becomes the second reference voltage. Thus, the current flowing only to the amplifier is adjusted. According to such a configuration, since the current is adjusted stepwise by updating the second reference voltage using the first reference current, an error caused by non-linear variation of the current detection circuit is reduced, The current adjustment accuracy can be improved.

  According to a second aspect of the technology disclosed in the present specification, an amplifier through which a current for performing amplification flows is connected to the amplifier in parallel, and a current flows in parallel with the current flowing through the amplifier. A reference current circuit, a current detection circuit that detects the current flowing through the amplifier and the reference current circuit, and converts the value of the current into an output voltage, and adjusts the current flowing through the amplifier and the reference current circuit. And an adjusting unit, wherein when the adjusting unit causes the current to flow only to the reference current circuit, the current detection circuit detects the current flowing to the reference current circuit as a first reference current, and Converting the value of the first reference current into a first reference voltage, and when the first reference current is passed through the reference current circuit and the amplifier by the adjustment unit, The current detection circuit converts the value of the first reference current flowing through the reference current circuit and the value of the first reference current flowing through the amplifier into a second reference voltage, and the adjustment unit includes: The current flowing only through the amplifier is adjusted so that the output voltage of the current detection circuit becomes the second reference voltage when the current flows only through the amplifier. According to such a configuration, since the current is adjusted stepwise by updating the second reference voltage using the first reference current, an error caused by non-linear variation of the current detection circuit is reduced, The current adjustment accuracy can be improved.

  A third aspect of the technology disclosed in the specification of the present application includes the above-described current adjusting device. According to such a configuration, the characteristics of the individual antenna elements in the adaptive array antenna can be matched with high accuracy, so that the main lobe and the side lobe of the adaptive array antenna can be controlled with high accuracy.

  Further, objects, features, aspects, and advantages of the technology disclosed in the present specification will become more apparent from the detailed description given below and the accompanying drawings.

FIG. 5 is a diagram illustrating an example of a configuration of a transmission amplifier in an adaptive array antenna according to the embodiment. 9 is a flowchart illustrating an example of a drain current adjustment operation of a plurality of amplifiers mounted on the transmission amplifier of the adaptive array antenna according to the embodiment. FIG. 3 is a diagram illustrating an example of a relationship between an updated reference gate voltage Vg _-REF and an updated reference drain current when the operation of Step 2A in FIG. 2 is repeated. FIG. 5 is a diagram illustrating an example of a configuration of a transmission amplifier in an adaptive array antenna according to the embodiment. 9 is a flowchart illustrating an example of a drain current adjustment operation of a plurality of amplifiers mounted on a transmission amplifier (in particular, a high-frequency amplifier) of the adaptive array antenna according to the embodiment. FIG. 6 is a diagram illustrating an example of a relationship between an updated reference gate voltage Vg _-REF and an updated reference drain current when the operation of Step 2B in FIG. 5 is repeated. FIG. 5 is a diagram illustrating an example of a configuration of a transmission amplifier in an adaptive array antenna according to the embodiment. 5 is a flowchart illustrating an example of a drain current adjustment operation of a plurality of amplifiers mounted on a transmission amplifier (particularly, a multi-stage amplifier) of the adaptive array antenna according to the embodiment. 2 is a flowchart illustrating an example of a drain current adjustment operation of a plurality of amplifiers mounted on the transmission amplifier of the adaptive array antenna according to the embodiment having the configuration illustrated in FIG. 1. FIG. 3 is a diagram illustrating an example of a configuration of an adaptive array antenna according to the embodiment.

  Hereinafter, embodiments will be described with reference to the accompanying drawings.

  The drawings are schematically shown, and for convenience of explanation, the configuration is omitted or simplified as appropriate. Further, the relationship between the size and the position of the configuration and the like shown in the different drawings is not necessarily accurately described, and can be appropriately changed. Further, hatching may be applied to drawings such as plan views which are not cross-sectional views so as to facilitate understanding of the contents of the embodiments.

  In the following description, the same components are denoted by the same reference numerals, and their names and functions are the same. Therefore, a detailed description thereof may be omitted to avoid duplication.

  Further, in the following description, even when an ordinal number such as “first” or “second” may be used, these terms are used to understand the contents of the embodiments. It is used for convenience for the sake of simplicity, and is not limited to the order that can be generated by these ordinal numbers.

<First embodiment>
Hereinafter, a current adjusting method and a current adjusting device according to the present embodiment will be described.

<About the configuration of the transmission amplifier>
FIG. 1 is a diagram illustrating an example of a configuration of a transmission amplifier in an adaptive array antenna according to the present embodiment. The transmission amplifier includes a current adjustment circuit corresponding to a current adjustment device.

  As shown in FIG. 1, the transmission amplifier includes amplifier 100, amplifier 110... Amplifier 1n0, digital-to-analog converter (DAC) 200, DAC 210. The control circuit unit 300 includes a control circuit unit 300, a current detection circuit 400, a power supply 500 for drain bias, and a reference current circuit 600. In the configuration, the current detection circuit 400 and the reference current circuit 600 correspond to a current adjustment circuit.

  The amplifier 100, the amplifier 110,..., The amplifier 1n0 are connected to the respective antenna elements constituting the adaptive array antenna.

Amplifier 100, the amplifier 110 ... amplifier 1N0, the drain current _{I d0,} the drain current _{I d1} ... drain current _{I dn} for adjusting and controlling the gate voltage is an operating current of the respective amplifier, DAC 200, DAC210... DAC2n0 are connected respectively.

  The drain bias power supply 500 is connected to the drain terminal of each of the amplifiers 100, 110,...

  The reference current circuit 600 includes a resistor 601 and a transistor 602 for generating a reference current. Here, the transistor 602 is connected to the control processing unit 301 in the control circuit unit 300.

  The transistor 602 is used here as a switch. The transistor 602 conducts current between the collector and the emitter (or between the drain and the source) when a predetermined voltage is applied from the control processing unit 301 to the base terminal (or the gate terminal). Further, the transistor 602 performs control so that current does not flow by setting the voltage value of the base (or the gate) to 0 V.

  Assuming that the impedance between the collector and the emitter (or between the drain and the source) when a predetermined voltage is applied to the base terminal (or the gate terminal) of the transistor can be ignored, the reference current circuit 600 The flowing current is represented by the following equation (2).

Here, _{V D} is the voltage of the drain bias power supply 500. As shown in an example in Expression (2), the magnitude of the reference current I _REF can be adjusted based on the resistance R _{REF of the} resistor 601. Here, the value of the reference current I _REF is determined by the current detection. The reference current I _REF-min which is the minimum value of the current value detectable in the circuit 400 is set. Here, the minimum value of the detectable current value is a value determined by device accuracy of a Hall element or the like, and is usually about 5 mA. However, if a high-performance device is used, the value may be smaller. Can also.

  The current detection circuit 400 includes a current sensor circuit 401 and an analog to digital converter (ADC) 402. An output terminal of the ADC 402 is connected to the control processing unit 301.

  The control circuit unit 300 includes a control processing unit 301, a memory 302, and a gate setting voltage output unit 303.

<Configuration of Adaptive Array Antenna>
Here, the configuration of the adaptive array antenna will also be described. FIG. 10 is a diagram illustrating an example of a configuration of an adaptive array antenna according to the present embodiment.

  As shown in FIG. 10, the adaptive array antenna includes an antenna 1, a transmission / reception switch 2 connected to the antenna 1, a transmission amplifier 3 for inputting to the transmission / reception switch 2, and a transmission / reception switch 2. A receiving amplifier 4 for receiving an output, a phase shifter 5a for inputting to the transmitting amplifier 3, a phase shifter 5b for receiving an output from the receiving amplifier 4, an input to the phase shifter 5a, and a phase shifting. A transmitting / receiving circuit 6 for receiving an output from the transmitter / receiver 5b; a control processing unit 8 for communicating with the transmitting / receiving circuit 6; and a baseband signal processing unit 7 for communicating with the transmitting / receiving circuit 6. The control processing unit 8 also performs communication with the transmission amplifier 3, the reception amplifier 4, the phase shifter 5a, and the phase shifter 5b.

<Operation of transmission amplifier>
Next, the operation of the transmission amplifier according to the present embodiment will be described with reference to FIGS. Here, FIG. 2 is a flowchart showing an example of a drain current adjustment operation of a plurality of amplifiers mounted on the transmission amplifier of the adaptive array antenna according to the present embodiment. The control circuit unit 300 including the control processing unit 301 may automatically operate based on a program created in advance or may operate in response to an external instruction. Good.

  First, in Step 1A, a value of a reference current for adjusting a drain current is determined.

Specifically, in step ST1A-1, the control processing unit 301 outputs the output voltages of the DAC 200, DAC 210,... DAC 2n0 connected to the gate terminals of the respective amplifiers via the gate setting voltage output unit 303. The drain current I _d0 and the drain current I _{d1 of the} amplifier 100, the amplifier 110,..., The amplifier 1n0, and the drain current I _dn .

  At the same time, the control processing unit 301 applies a predetermined voltage to the base terminal (or gate terminal) of the transistor 602 so that the transistor 602 of the reference current circuit 600 is turned on.

In this state, the reference current I _REF-min that satisfies the relationship of the expression (2) and is the minimum detectable current value flows through the reference current circuit 600.

Next, in step ST1A-2, the reference current I _REF-min flowing in the reference current circuit 600 is detected by the current sensor circuit 401.

The output voltage V _det obtained by detecting the reference current I _REF-min in the current sensor circuit 401 is converted into a digital signal in the ADC 402. Then, in the control processing unit 301, the output voltage V _det converted into a digital signal is stored in the memory 302 as a reference voltage V _REF for drain current adjustment.

  Next, in step ST1A-3, the control processing unit 301 controls the voltage applied to the base terminal (or the gate terminal) of the transistor 602 so that the transistor 602 in the reference current circuit 600 is turned off. , The detection of the reference current is completed.

Subsequently, in Step 2A, the drain current I _d0 , the drain current I _d1, ..., The drain current I _dn of each of the amplifiers 100, 110,.

It is assumed that the set drain current _Id-target , which is the set value of the drain current, is stored in the memory 302 in advance. Here, the control processing unit 301 has a function of counting the number of adjustments J of the drain current (J = 1 to m, where m is an integer).

First, in step ST2A-1, only the DAC for gate voltage adjustment corresponding to any one of the amplifiers 100, 110,..., 1n0 (I = 0) is controlled, and the corresponding amplifier is controlled. Make the drain current flow. At the same time, the control processing unit 301 reads the output voltage V _det output from the current detection circuit 400.

The control processing unit 301 compares the reference voltage V _REF stored in the memory 302 with the output voltage V _det, and controls the gate setting voltage output unit so that the value of the output voltage V _det becomes equal to the reference voltage V _REF. The gate voltage of the corresponding DAC and the corresponding amplifier via 303 are adjusted.

Next, in step ST2A-2, the output voltage of the DAC, which is the gate voltage of one amplifier adjusted in step ST2A-1, is stored in the memory 302 as the reference gate voltage Vg _-REF of the amplifier.

Next, in step ST2A-3, whether the difference between the reference drain current corresponding to the reference gate voltage Vg- _REF obtained by the above adjustment and the set drain current Id- _target is within a predetermined range. Determine whether or not. Specifically, the control processing unit 301 determines whether or not the following expression (3) is satisfied.

[J × I _REF-min ] in the above equation (3) is the value of the drain current for each adjustment of one amplifier. For example, when the adjustment of the drain current of one amplifier is the first time, the control processing unit 301 substitutes the set drain current I _d-target and the reference drain current while substituting J = 1 in Expression (3). It is determined whether the difference is equal to or less than the reference drain current.

Usually, the set drain current _Id-target is a sufficiently large value with respect to the reference drain current. Therefore, in the first adjustment, the above expression (3) cannot be satisfied, and the drain current is readjusted.

  In step ST2A-3, when the equation (3) is satisfied, that is, when it corresponds to “YES” branched from step ST2A-3 shown in FIG. 2, the process proceeds to Step 3A. On the other hand, if equation (3) is not satisfied in step ST2A-3, that is, if “NO” branches off from step ST2A-3 shown in FIG. 2, the substitution in equation (3) is performed. The process proceeds to step ST2A-4 while setting J to be performed to J + 1.

Next, in step ST2A-4, the second and subsequent adjustments of the drain current are performed. That is, the reference voltage V _REF for drain current adjustment is updated.

Specifically, the gate voltage of the amplifier is set to the reference gate voltage Vg _-REF stored in the memory 302 in step ST2A-2, and the transistor 602 in the reference current circuit 600 is turned on to set the reference current I _REF By flowing _−min , the current detection circuit 400 detects the sum of the currents flowing through the amplifier and the reference current circuit 600, that is, the sum of the reference current I _REF-min and the reference current I _REF-min . Then, the value of the reference voltage V _REF stored in the memory 302 is updated based on the output voltage V _det detected in this state.

Then, in step ST2A-5, after the reference voltage V _REF is updated, the transistor 602 of the reference current circuit 600 is turned off.

Then, the process returns to step ST2A-1 to adjust the drain current again based on the updated reference voltage V _REF . In step ST2A-1, only the gate voltage adjustment DAC corresponding to the same amplifier is controlled again so that the drain current flows to the corresponding amplifier. At the same time, the control processing unit 301 reads the output voltage V _det output from the current detection circuit 400.

In the control processing section 301 performs comparison between the updated reference voltage _{V REF} is stored in the memory 302 and the output voltage _{V det,} as the value of the output voltage _{V det} is equal to the reference voltage _{V REF} which is updated , Adjust the gate voltage of the corresponding amplifier.

Next, in step ST2A-2, the output voltage of the DAC which is the gate voltage of one amplifier adjusted in step ST2A-1 is stored in the memory 302 as the updated reference gate voltage Vg _-REF of the amplifier. You.

Each time the number of times the drain current is adjusted in the above-described procedure overlaps, the reference drain current corresponding to the updated reference gate voltage _Vg-REF increases by the reference current I _REF-min . Then, the difference from the set drain current _Id-target also decreases.

  Then, Step ST2A-1, Step ST2A-2, and Step ST2A-3 are performed until Expression (3) in Step ST2A-3 is satisfied.

FIG. 3 is a diagram illustrating an example of the relationship between the updated reference gate voltage Vg _-REF and the updated reference drain current when the operation of Step 2A in FIG. 2 is repeated. In FIG. 3, the vertical axis indicates a current value, and the horizontal axis indicates a voltage value.

As shown in the example in FIG. 3, each time the reference gate voltage _Vg-REF of one amplifier is adjusted once, the reference drain current of the amplifier increases by the reference current I _REF-min .

  Next, when a reference drain current that satisfies Expression (3) in Step ST2A-3 is obtained, the process proceeds to Step 3A.

Then, in step ST3A-1 of Step 3A, the reference gate voltage Vg- _REF stored in the memory 302 is stored in the memory 302 as a gate voltage set value of the corresponding amplifier.

  Subsequently, when the amplifier whose gate voltage is adjusted corresponds to I = n (n is the number of all amplifiers), that is, corresponds to "YES" branched from step ST3A-1 shown in FIG. If so, the operation ends. On the other hand, if the amplifier whose gate voltage has been adjusted is I ≠ n, that is, if it corresponds to “NO” branched from step ST3A-1 shown in FIG. 2, the next amplifier (I + 1) In order to adjust the gate voltage of (Step ST3A-3), the process returns to Step 1A.

  As described above, the gate voltage set values adjusted for all the amplifiers 100, 110,..., 1n0 can be set.

Note that the reference current circuit 600 can generate a current having a minimum value that can be detected by the current detection circuit 400 (that is, the reference current I _REF-min ), and the reference current circuit 600 can be controlled by the control processing unit 301. _Any circuit may be used as long as it can turn ON / OFF generation of I _REF-min .

As described above, in the present embodiment, the reference current circuit 600 is provided as a means for calibrating the current detection circuit 400 for adjusting the drain current of the amplifier. Then, the current generated by the reference current circuit 600 is set as a reference current I _REF-min which is a minimum value detectable by the current detection circuit 400, and the drain current of the amplifier is adjusted stepwise by the reference current I _REF-min .

By doing so, the drain current is adjusted stepwise by updating the reference voltage obtained based on the reference current. Therefore, the sensitivity a of the current detection circuit 400 and the value of V _offset for the current detection circuit 400 with respect to the equation (1) are obtained. An error caused by non-linear variation can be reduced, and the accuracy of adjusting the drain current can be improved.

  Also, when changing the drain current of the amplifier, the smaller the current value detected by the current detection circuit 400 (that is, the finer the resolution), the more flexibly the response can be made.

  In addition, since the configuration of the reference current circuit 600 can be configured by one resistor and a control transistor, the size of the circuit can be reduced.

<Second embodiment>
A current adjustment method and a current adjustment device according to the present embodiment will be described. In the following description, the same components as those described in the above-described embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted as appropriate. .

<About the configuration of the transmission amplifier>
In the first embodiment, the reference current circuit 600 includes a resistor 601 for generating a current corresponding to a minimum value detectable by the current detection circuit 400, and a transistor 602 for performing ON / OFF control of the reference current I _REF-min. And On the other hand, in the configuration described in this embodiment, the reference current circuit 600A includes the resistor 611 that generates an offset current and the transistor 612 that performs ON / OFF control of the offset current.

  FIG. 4 is a diagram illustrating an example of a configuration of a transmission amplifier in an adaptive array antenna according to the present embodiment. The transmission amplifier includes a current adjustment circuit.

  As shown in FIG. 4, the transmission amplifier includes amplifier 100, amplifier 110... Amplifier 1n0, DAC 200, DAC 210... DAC 2n0, control circuit unit 300, current detection circuit 400, and drain bias. A power supply 500 and a reference current circuit 600A are provided.

  The reference current circuit 600A includes a reference current source circuit including a resistor 601 and a transistor 602, and an offset current source circuit including a resistor 611 and a transistor 612.

Here, the offset current flowing in the offset current source circuit is an arbitrary fixed current having a current value smaller than the set drain current _Id-target .

  The transistor 602 and the transistor 612 are both connected to the control processing unit 301 in the control circuit unit 300.

  The transistors 602 and 612 are used here as switches. The transistor 602 and the transistor 612 conduct current between a collector and an emitter (or between a drain and a source) when a predetermined voltage is applied from the control processing unit 301 to a base terminal (or a gate terminal). Further, the transistor 602 and the transistor 612 are controlled so that current does not flow by setting a voltage value of a base (or a gate) to 0 V.

The resistance value of the resistor 611 and the resistor _{R OFFSET,} when the voltage value of the drain bias power supply 500 and _{V D,} referring to Equation (2), to generate the offset current _{I OFFSET} represented by the following formula (4) be able to.

<Operation of transmission amplifier>
Next, the operation of the transmission amplifier according to the present embodiment will be described with reference to FIGS. Here, FIG. 5 is a flowchart showing an example of a drain current adjustment operation of a plurality of amplifiers mounted on a transmission amplifier (particularly, a high-frequency amplifier) of the adaptive array antenna according to the present embodiment.

  First, in Step 1B, a value of a reference current for adjusting a drain current is determined.

Specifically, in step ST1B-1, the control processing unit 301 outputs the output voltages of the DAC 200, DAC 210,... DAC 2n0 connected to the gate terminals of the respective amplifiers via the gate setting voltage output unit 303. The drain current I _d0 and the drain current I _{d1 of the} amplifier 100, the amplifier 110,..., The amplifier 1n0, and the drain current I _dn .

  At the same time, the control processing unit 301 sends a signal to the base terminal (or gate terminal) of the transistor 602 and the base terminal (or gate terminal) of the transistor 612 so that the transistor 602 and the transistor 612 of the reference current circuit 600A are turned on. Apply a predetermined voltage.

In this state, a reference current I _REF-min that satisfies the relationship of Expression (2) and is the minimum detectable current value flows through the reference current source circuit of the reference current circuit 600A. In this state, in the offset current source circuit of the reference current circuit 600A, the offset current I _OFFSET which is an arbitrary fixed current that satisfies the relationship of the expression (4) and is smaller than the set drain current I _d-target is provided. Flows.

Next, in step ST1B-2, the current detection circuit 400 detects the sum of the reference current I _REF-min and the offset current I _OFFSET flowing in the reference current circuit 600A.

The output voltage V _det obtained by detecting the sum of the reference current I _REF-min and the offset current I _OFFSET by the current sensor circuit 401 of the current detection circuit 400 is converted into a digital signal by the ADC 402. Then, in the control processing unit 301, the output voltage V _det converted into a digital signal is stored in the memory 302 as a reference voltage V _REF for drain current adjustment.

  Next, in step ST1B-3, the control processing unit 301 causes the base terminal (or gate terminal) of the transistor 602 and the base terminal of the transistor 612 so that the transistor 602 and the transistor 612 in the reference current circuit 600A are turned off. By controlling the voltage applied to (or the gate terminal), detection of the reference current and detection of the offset current are completed.

Subsequently, in Step 2B, the drain current I _d0 , the drain current I _d1, ..., The drain current I _dn of each of the amplifier 100, the amplifier 110,.

First, in step ST2B-1, only the DAC for adjusting the gate voltage corresponding to any one of the amplifiers 100, 110,..., 1n0 (I = 0) is controlled, and the corresponding amplifier is controlled. Make the drain current flow. At the same time, the control processing unit 301 reads the output voltage V _det output from the current detection circuit 400.

The control processing unit 301 compares the reference voltage V _REF stored in the memory 302 with the output voltage V _det, and controls the gate setting voltage output unit so that the value of the output voltage V _det becomes equal to the reference voltage V _REF. The gate voltage of the corresponding DAC and the corresponding amplifier via 303 are adjusted.

Next, in step ST2B-2, the output voltage of the DAC that is the gate voltage of one amplifier adjusted in step ST2B-1 is stored in the memory 302 as the reference gate voltage Vg _-REF of the amplifier.

Next, in step ST2B-3, is the difference between the reference drain current corresponding to the reference gate voltage Vg- _REF obtained by the above adjustment and the set drain current Id- _target within a predetermined range? Determine whether or not. Specifically, the control processing unit 301 determines whether or not the following expression (5) is satisfied.

  In step ST2B-3, when the equation (5) is satisfied, that is, when it corresponds to “YES” branched from step ST2B-3 shown in FIG. 5, the process proceeds to Step 3B. On the other hand, if equation (5) is not satisfied in step ST2B-3, that is, if it corresponds to “NO” branched from step ST2B-3 shown in the example of FIG. 5, substitution in equation (5) is performed. The process proceeds to step ST2B-4 while setting J to be performed to J + 1.

Next, in step ST2B-4, the second and subsequent adjustments of the drain current are performed. That is, the reference voltage V _REF for drain current adjustment is updated.

Specifically, the gate voltage of the amplifier is set to the reference gate voltage Vg _-REF stored in the memory 302 in step ST2B-2, and only the transistor 602 in the reference current circuit 600A is turned on. The current detection circuit 400 detects the sum of the currents flowing through the amplifier and the reference current circuit 600A. Then, the value of the reference voltage V _REF stored in the memory 302 is updated based on the output voltage V _det detected in this state.

Then, in step ST2B-5, after the reference voltage V _REF is updated, the transistor 602 of the reference current circuit 600A is turned off.

Then, the process returns to step ST2B-1 to adjust the drain current again based on the updated reference voltage V _REF . In step ST2B-1, only the DAC for gate voltage adjustment corresponding to the same amplifier is controlled again so that the drain current flows to the corresponding amplifier. At the same time, the control processing unit 301 reads the output voltage V _det output from the current detection circuit 400.

In the control processing section 301 performs comparison between the updated reference voltage _{V REF} is stored in the memory 302 and the output voltage _{V det,} as the value of the output voltage _{V det} is equal to the reference voltage _{V REF} which is updated , Adjust the gate voltage of the corresponding amplifier.

Next, in step ST2B-2, the output voltage of the DAC that is the gate voltage of one amplifier adjusted in step ST2B-1 is stored in the memory 302 as the updated reference gate voltage Vg _-REF of the amplifier. You.

Each time the number of times the drain current is adjusted in the above-described procedure overlaps, the reference drain current corresponding to the updated reference gate voltage _Vg-REF increases by the reference current I _REF-min . Then, the difference from the set drain current _Id-target also decreases.

  Then, steps ST2B-1, ST2B-2, and ST2B-3 are performed until Expression (5) in step ST2B-3 is satisfied.

FIG. 6 is a diagram illustrating an example of the relationship between the updated reference gate voltage Vg _-REF and the updated reference drain current when the operation of Step 2B in FIG. 5 is repeated. In FIG. 6, the vertical axis indicates a current value, and the horizontal axis indicates a voltage value.

As shown in the example in FIG. 6, first, the reference drain current of the amplifier is set to be equal to the sum of the reference current I _REF-min and the offset current I _OFFSET . Then, thereafter, each time the reference gate voltage V _g-REF of one amplifier is adjusted once, the reference drain current of the amplifier is increased by the reference current I _REF-min .

By performing such an adjustment, the number of adjustments required to approach the set drain current _Id-target can be reduced.

  Next, when a reference drain current satisfying the expression (5) in Step ST2B-3 is obtained, the process proceeds to Step 3B.

Then, in step ST3B-1 of Step 3B, the reference gate voltage Vg- _REF stored in the memory 302 is stored in the memory 302 as a gate voltage set value of the corresponding amplifier.

  Subsequently, when the amplifier whose gate voltage has been adjusted corresponds to I = n (n is the number of all amplifiers), that is, corresponds to "YES" branched from step ST3B-1 shown in FIG. If so, the operation ends. On the other hand, if the amplifier whose gate voltage has been adjusted is I ≠ n, that is, if it corresponds to “NO” branched from step ST3B-1 shown in FIG. 5, the next amplifier (I + 1) (Step ST3B-3), the process returns to Step 1B.

  As described above, the gate voltage set values adjusted for all the amplifiers 100, 110,..., 1n0 can be set.

As described above, in the present embodiment, the reference current circuit 600A is provided as a means for calibrating the current detection circuit 400 for adjusting the drain current of the amplifier. Then, the current generated by the reference current circuit 600A is defined as the sum of the reference current I _REF-min and the offset current I _OFFSET, and the drain current of the amplifier is adjusted stepwise by the reference current I _REF-min .

By doing so, it is possible to reduce errors caused by nonlinear variations in the values of the sensitivity a and V _offset of the current detection circuit 400, and improve the accuracy of adjusting the drain current. In addition, since the adjustment is started from the current value to which the offset current I _OFFSET is added, the number of times of adjustment of the drain current can be reduced.

<Third embodiment>
A current adjustment method and a current adjustment device according to the present embodiment will be described. In the following description, the same components as those described in the above-described embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted as appropriate. .

<About the configuration of the transmission amplifier>
In the first embodiment and the second embodiment, the amplifier 100, the amplifier 110,..., And the amplifier 1n0 are single-stage amplifiers. On the other hand, in the present embodiment, a case will be described in which the amplifiers connected to the respective antenna elements have a multi-stage configuration. In the present embodiment, a three-stage amplifier is shown as an example, but the multi-stage amplifier is not limited to a three-stage amplifier.

  FIG. 7 is a diagram illustrating an example of a configuration of a transmission amplifier in an adaptive array antenna according to the present embodiment. The transmission amplifier includes a current adjustment circuit.

  As shown in FIG. 7, the transmission amplifier includes amplifier 100B, amplifier 110B... Amplifier 1n0B, DAC 200, DAC 201, DAC 202, DAC 210, DAC 211, DAC 212. 300, a current detection circuit 400, a power supply 500 for drain bias, and a reference current circuit 600A.

  The amplifier 100B is an amplifier having a three-stage configuration including an amplifier 101, an amplifier 102, and an amplifier 103. DAC 200, DAC 201, and DAC 202 for adjusting the gate voltage are connected to the gate terminals of amplifier 101, amplifier 102, and amplifier 103, respectively.

  The amplifier 110B is an amplifier having a three-stage configuration including an amplifier 111, an amplifier 112, and an amplifier 113. DAC 210, DAC 211, and DAC 212 for adjusting the gate voltage are connected to the gate terminals of the amplifier 111, the amplifier 112, and the amplifier 113, respectively.

  The amplifier 1n0B is an amplifier having a three-stage configuration including an amplifier 1n1, an amplifier 1n2, and an amplifier 1n3. DACs 2n0, DAC2n1, and DAC2n2 for adjusting gate voltages are connected to gate terminals of the amplifiers 1n1, 1n2, and 1n3, respectively.

  The control processing unit 301 controls output voltages of the DAC 200, DAC 201, DAC 202, DAC 210, DAC 211, DAC 212,... DAC 2n0, DAC 2n1, and DAC 2n2 via the gate setting voltage output unit 303.

<Operation of transmission amplifier>
Next, the operation of the transmission amplifier according to the present embodiment will be described with reference to FIG. Here, FIG. 8 is a flowchart showing an example of a drain current adjustment operation of a plurality of amplifiers mounted on a transmission amplifier (particularly, a multi-stage amplifier) of the adaptive array antenna according to the present embodiment.

  First, in Step 1B, a value of a reference current for adjusting a drain current is determined.

Subsequently, in Step 2C, the drain current I _d0 , the drain current I _d1, ..., The drain current I _dn of each of the amplifiers 100B, 110B,.

First, in step ST2C-1, only the DAC for gate voltage adjustment corresponding to one stage (K = 1) of any one of the amplifiers 100B, 110B... 1n0B (I = 0) , So that the drain current flows to the corresponding amplifier. At the same time, the control processing unit 301 reads the output voltage V _det output from the current detection circuit 400.

The control processing unit 301 compares the reference voltage V _REF stored in the memory 302 with the output voltage V _det, and controls the gate setting voltage output unit so that the value of the output voltage V _det becomes equal to the reference voltage V _REF. The gate voltage of the corresponding DAC via the 303 and the amplifier of the corresponding stage are adjusted.

Next, in step ST2C-2, the output voltage of the DAC, which is the gate voltage of one amplifier adjusted in step ST2C-1, is stored in the memory 302 as the reference gate voltage Vg _-REF of the amplifier.

Next, in step ST2C-3, is the difference between the reference drain current corresponding to the reference gate voltage Vg- _REF obtained by the above adjustment and the set drain current Id- _target within a predetermined range? Determine whether or not. Specifically, the control processing unit 301 determines whether Expression (5) is satisfied.

  In step ST2C-3, if the equation (5) is satisfied, that is, if it corresponds to “YES” branched from step ST2C-3 shown in FIG. 8, the process proceeds to step ST2C-6. On the other hand, if equation (5) is not satisfied in step ST2C-3, that is, if it corresponds to “NO” branched from step ST2C-3 shown in the example of FIG. 8, substitution in equation (5) is performed. The process proceeds to step ST2C-4 while setting J to be performed to J + 1.

Next, in step ST2C-4, the second and subsequent adjustments of the drain current are performed. That is, the reference voltage V _REF for drain current adjustment is updated.

Specifically, the gate voltage of the amplifier is set to the reference gate voltage Vg _-REF stored in the memory 302 in step ST2C-2, and only the transistor 602 in the reference current circuit 600A is turned on. The current detection circuit 400 detects the sum of the currents flowing through the amplifier and the reference current circuit 600A. Then, the value of the reference voltage V _REF stored in the memory 302 is updated based on the output voltage V _det detected in this state.

Then, in step ST2C-5, after the reference voltage V _REF is updated, the transistor 602 of the reference current circuit 600A is turned off.

Then, the process returns to step ST2C-1 to adjust the drain current again based on the updated reference voltage V _REF . In step ST2C-1, only the gate voltage adjustment DAC corresponding to the same amplifier is controlled again so that the drain current flows to the corresponding amplifier. At the same time, the control processing unit 301 reads the output voltage V _det output from the current detection circuit 400.

In the control processing section 301 performs comparison between the updated reference voltage _{V REF} is stored in the memory 302 and the output voltage _{V det,} as the value of the output voltage _{V det} is equal to the reference voltage _{V REF} which is updated , Adjust the gate voltage of the corresponding amplifier.

Next, in step ST2C-2, the output voltage of the DAC, which is the gate voltage of one amplifier adjusted in step ST2C-1, is stored in the memory 302 as the updated reference gate voltage Vg _-REF of the amplifier. You.

Each time the number of times the drain current is adjusted in the above-described procedure overlaps, the reference drain current corresponding to the updated reference gate voltage _Vg-REF increases by the reference current I _REF-min . Then, the difference from the set drain current _Id-target also decreases.

  Steps ST2C-1, ST2C-2, and ST2C-3 are performed until Expression (5) in step ST2C-3 is satisfied.

  Next, when the reference drain current satisfying the expression (5) in Step ST2C-3 is obtained, the process proceeds to Step ST2C-6.

Then, in step ST2C-6, the reference gate voltage Vg- _REF stored in the memory 302 is stored in the memory 302 as a gate voltage set value of the corresponding amplifier.

Subsequently, the number of stages of the amplifier the gate voltage is adjusted K = n _{2 (n} 2 is the number of stages of the amplifier) may correspond to, i.e., branches from step ST2C-7 of example in FIG. 8 is shown "YES" If it corresponds to, the process proceeds to Step 3C. On the other hand, if the number of stages of the amplifier gate voltage is adjusted is K ≠ n _2, that is, when corresponding to "NO" branching from step ST2C-7 of example in FIG. 8 is indicated, the same amplifier The process proceeds to step ST2C-8 to adjust the gate voltage of the next stage (K + 1).

Next, in step ST2C-8, the previously adjusted gate voltage of the amplifier is set to the gate voltage set value stored in the memory 302 in step ST2C-6, and the transistors 602 and 612 in the reference current circuit 600A are turned off. By turning on, the current detection circuit 400 detects the sum of the currents flowing through the amplifier and the reference current circuit 600A. Then, the value of the reference voltage V _REF stored in the memory 302 is updated based on the output voltage V _det detected in this state.

Then, in step ST2C-9, after the reference voltage V _REF is updated, the transistors 602 and 612 in the reference current circuit 600A are turned off.

Then, the process returns to step ST2C-1 in order to adjust the drain current of the amplifier in the next stage based on the updated reference voltage V _REF . In step ST2C-1, the DAC for gate voltage adjustment corresponding to the amplifier including the already adjusted stage and the next stage is controlled so that the drain current flows through the amplifier of the corresponding stage. At the same time, the control processing unit 301 reads the output voltage V _det output from the current detection circuit 400.

  In a multi-stage amplifier, if the drain current of the next-stage amplifier is adjusted while the previous-stage amplifier is not operating, an error may occur in the gate voltage value at the time of drain current adjustment due to mismatch of input impedance. Therefore, when adjusting the amplifiers in the second and subsequent stages, the amplifiers up to the previous stage are operated with the already adjusted reference drain current, and the next-stage amplifier is adjusted in this state.

The control processing unit 301 compares the reference voltage V _REF stored in the memory 302 with the output voltage V _det, and controls the gate setting voltage output unit so that the value of the output voltage V _det becomes equal to the reference voltage V _REF. The gate voltage of the corresponding DAC and the corresponding amplifier via 303 are adjusted.

Next, in step ST2C-2, the output voltage of the DAC, which is the gate voltage of the stage amplifier adjusted for the first time in step ST2C-1, is stored in the memory 302 as the reference gate voltage Vg _-REF of the stage amplifier. You.

  Steps ST2C-1, ST2C-2, and ST2C-3 are performed until Expression (5) in step ST2C-3 is satisfied.

On the other hand, in Step 3C, when the amplifier whose gate voltage has been adjusted corresponds to I = n ₁ (n ₁ is the number of all amplifiers), that is, the process branches from step ST3C-2 shown in FIG. If the answer is "YES", the operation is terminated. On the other hand, if the amplifier gate voltage is adjusted is I ≠ n _1, that is, when corresponding to "NO" branching from Step ST3c-2 of Example 8 is shown, the next amplifier (I + 1 )) (Step ST3C-3), the process returns to Step 1B.

  As described above, the gate voltage set values adjusted for all the amplifiers 100B, 110B,..., And 1n0B can be set.

  According to the configuration according to the present embodiment, even when an amplifier having a multi-stage configuration is used, the drain current of each amplifier can be adjusted.

<Fourth embodiment>
A current adjustment method and a current adjustment device according to the present embodiment will be described. In the following description, the same components as those described in the above-described embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted as appropriate. .

  In the first embodiment, the second embodiment, and the third embodiment, a method using a reference current circuit has been described as a method of adjusting the drain current of each amplifier constituting the adaptive array antenna.

  In the above method, the long-term error of the current detection circuit 400 can be suppressed by using the reference current circuit for comparison each time each amplifier is adjusted.

  On the other hand, since the reference current circuit is used for comparison each time each amplifier is adjusted, the number of adjustments may increase.

<Operation of transmission amplifier>
The operation of the transmission amplifier according to the present embodiment will be described with reference to FIG. Here, FIG. 9 is a flowchart illustrating an example of a drain current adjustment operation of a plurality of amplifiers mounted on the transmission amplifier of the adaptive array antenna according to the present embodiment having the configuration illustrated in FIG. .

  First, in Step 1A, a value of a reference current for adjusting a drain current is determined (for details, see FIG. 2).

Subsequently, in Step2A, adjusting the drain current _{I d0} of the amplifier 100.

Next, in step ST3D-1, after the adjustment of the drain current of the first amplifier is completed, the reference gate voltage Vg- _REF stored in the memory 302 is stored in the memory 302 as the gate voltage set value of the amplifier. save.

  Then, the control processing unit 301 controls the voltage applied to the base terminal (or the gate terminal) of the transistor 602 so that the transistor 602 of the reference current circuit 600 is turned off.

  Subsequently, in Step 4D, the gate voltage of the next amplifier (I + 1) is adjusted.

  First, in step ST4D-1, all the amplifiers other than the amplifiers already adjusted are in the pinch-off state. Then, the gate voltage set value stored in the memory 302 is applied to the already adjusted amplifier in step ST3D-1.

In this state, the reference drain current flows through the already adjusted amplifier. The current sensor circuit 401 detects the current, and sets the output voltage V _det as the reference voltage V _REF (step ST4D-2). Thereafter, the already adjusted amplifier is brought into a pinch-off state (step ST4D-3).

Next, the current sensor circuit 401 detects a drain current flowing through the amplifier to be adjusted next. Then, the gate voltage of the amplifier is adjusted so that the output voltage V _det obtained by detecting the drain current by the current sensor circuit 401 becomes equal to the reference voltage V _REF (step ST4D-4).

Then, in step ST4D-5, the gate voltage when the output voltage V _det is equal to the reference voltage V _REF is stored in the memory 302 as a gate voltage set value of the amplifier. Then, the amplifier is brought into a pinch-off state.

  Next, when the amplifier whose gate voltage is adjusted corresponds to I = n (n is the number of all amplifiers), that is, corresponds to "YES" branched from step ST3D-2 shown in FIG. If so, the operation ends. On the other hand, if the amplifier whose gate voltage has been adjusted is I ≠ n, that is, if it corresponds to “NO” branched from step ST3D-2 shown in FIG. 9, the next amplifier (I + 1) In order to adjust the gate voltage, the process returns to step ST3D-3.

  As described above, in the present embodiment, the first amplifier performs the drain current adjustment using the reference current circuit 600. The drain current adjustment of the second and subsequent amplifiers is performed using the already adjusted first amplifier in place of the reference current circuit 600.

  By adjusting the drain currents of the second and subsequent amplifiers while comparing with the adjusted drain currents of the first amplifier, it is possible to prevent an increase in the number of adjustments while suppressing a long cycle error of the current detection circuit 400. be able to.

<About the effect produced by the embodiment described above>
Next, examples of effects produced by the above-described embodiment will be described. In the following description, the effect is described based on the specific configuration illustrated in the above-described embodiment. However, an example is described in the specification of the present application as long as the same effect is generated. May be replaced with another specific configuration shown.

  Further, the replacement may be performed over a plurality of embodiments. That is, a configuration in which the same effects are obtained by combining the respective configurations illustrated in the different embodiments may be employed.

According to the above-described embodiment, the current adjustment method includes a method of connecting at least one amplifier 100 through which a current for performing amplification (ie, an operation current) flows, and the amplifier 100 in parallel with the amplifier 100. This is performed in a circuit configuration including a reference current circuit 600 in which a current flows in parallel with a current flowing through the circuit and a current detection circuit 400. Here, the current detection circuit 400 detects a current flowing through the amplifier 100 and the reference current circuit 600. The current detection circuit 400 converts the detected value of the current into an output voltage. In the current adjustment method, when a current flows only in the reference current circuit 600, the current detection circuit 400 detects the current flowing in the reference current circuit 600 as a first reference current, and detects the current of the first reference current. Convert the value to a first reference voltage. Here, the first reference current corresponds to, for example, the reference current I _REF-min . The first reference voltage corresponds to, for example, the reference voltage V _REF . When the reference current I _REF-min flows through the reference current circuit 600 and the amplifier 100, respectively, the current detection circuit 400 determines the value of the reference current I _REF-min flowing through the reference current circuit 600 and the reference current flowing through the amplifier 100. The value is converted into a second reference voltage by _adding the value of I _REF-min . Here, the second reference voltage corresponds to, for example, the updated reference voltage V _REF . Then, the current flowing only to the amplifier 100 is adjusted so that the output voltage of the current detection circuit 400 becomes the updated reference voltage V _REF when the current flows only to the amplifier 100.

According to such a configuration, since the drain current is adjusted stepwise by updating the reference voltage V _REF using the reference current I _REF-min , the sensitivity a of the current detection circuit 400 and the value of V _offset An error caused by non-linear variation can be reduced, and the accuracy of adjusting the drain current can be improved. That is, the drain current can be adjusted without using the theoretical formulas of the values of the sensitivity a and V _offset of the current detection circuit 400.

  It should be noted that other configurations whose examples are described in the specification of the present application other than these configurations can be omitted as appropriate. That is, if at least these configurations are provided, the effects described above can be produced.

  However, when at least one of the other configurations exemplified in the specification of the present application is appropriately added to the above-described configuration, that is, in the specification of the present application which is not mentioned as the above-described configuration. The same effects can be obtained even when other configurations as shown in FIG.

  If there is no particular limitation, the order in which the processes are performed can be changed.

Further, according to the embodiment described above, reference current circuit 600 includes transistor 602. Then, a gate voltage applied to the transistor 602 when a current flows only in the reference current circuit 600 and the reference voltage V _REF is output from the current detection circuit 400 is set as a first gate voltage. Here, the first gate voltage corresponds to, for example, a predetermined voltage applied to a base terminal (or a gate terminal) of the transistor 602 so that the transistor 602 is turned on. Further, a gate voltage applied to the amplifier 100 when a current flows only through the amplifier 100 and the reference voltage V _REF is output from the current detection circuit 400 is defined as a second gate voltage. Here, the second gate voltage corresponds to, for example, the reference gate voltage _Vg-REF . When the first gate voltage is applied to the transistor 602 and the second gate voltage is applied to the amplifier 100, the current detection circuit 400 outputs the current flowing through the reference current circuit 600 (the reference current I _{REF− min} ) and the current (reference current I _REF-min ) flowing through the amplifier 100 are converted into an output voltage, and the reference voltage V _REF is updated. According to such a configuration, since the drain current is adjusted stepwise by updating the reference voltage V _REF using the reference current I _REF-min , the sensitivity a of the current detection circuit 400 and the value of V _offset An error caused by non-linear variation can be reduced, and the accuracy of adjusting the drain current can be improved.

Further, according to the embodiment described above, the value of reference current I _REF-min is the minimum value that can be detected by current detection circuit 400. According to such a configuration, the drain current can be adjusted at a fine stage, so that the current adjustment can be performed using a common circuit configuration for the set drain current _{Id-target under} various conditions. it can.

According to the embodiment described above, reference current circuit 600A includes a reference current source circuit and an offset current source circuit connected in parallel with the reference current source circuit. When a current flows through the reference current source circuit and the offset current source circuit, the current detection circuit 400 combines the current flowing through the reference current source circuit and the current flowing through the offset current source circuit as a second reference current. Detecting and converting the value of the second reference current into a third reference voltage. Here, the second reference current corresponds to, for example, the sum of the reference current I _REF-min and the offset current I _OFFSET . Further, the third reference voltage corresponds to, for example, the reference voltage V _REF . When the reference current I _REF-min flows through the reference current source circuit and the second reference current flows through the amplifier 100, the current detection circuit 400 outputs the reference current I _REF− The value of _{min and} the value of the second reference current flowing through the amplifier 100 are converted into a fourth reference voltage. Here, the fourth reference voltage corresponds to, for example, the updated reference voltage V _REF . Then, the current flowing only to the amplifier 100 is adjusted so that the output voltage of the current detection circuit 400 becomes the updated reference voltage V _REF when the current flows only to the amplifier 100. According to such a configuration, since the second reference current is a current including the offset current I _OFFSET , the number of adjustments required to approach the set drain current I _d-target can be reduced.

  According to the above-described embodiment, the amplifier 100B is a multi-stage amplifier. In the multistage amplifier 100B, the current is adjusted in order from the preceding stage. Further, after adjusting the current flowing through the first-stage amplifier 101 of the multi-stage amplifier 100B, the current is supplied to the second-stage amplifier 102, which is a stage subsequent to the first stage of the multi-stage amplifier 100B. When adjusting the flowing current, it is assumed that the adjusted current has been passed through the amplifier 101 of the first stage. According to such a configuration, even when an amplifier having a multi-stage configuration is used, the drain current of each amplifier can be adjusted.

Further, according to the above-described embodiment, the plurality of amplifiers 100 are connected in parallel with each other. Then, the current flowing only to each of the amplifiers 100 is adjusted so that the output voltage obtained by converting the value of the current flowing only to each of the amplifiers 100 by the current detection circuit 400 becomes equal among the plurality of amplifiers 100. Specifically, the gate voltage set value is applied to the already adjusted amplifier, and the output voltage V _det converted by the current detection circuit 400 becomes the reference voltage V _REF . When adjusting the drain current of another amplifier, the applied gate voltage is adjusted such that the output voltage V _det of the current detection circuit 400 becomes equal to the reference voltage V _REF . According to such a configuration, by adjusting the drain currents of the second and subsequent amplifiers while comparing them with the adjusted drain currents of the first amplifier, a long-period error of the current detection circuit 400 is suppressed. In addition, it is possible to prevent the number of adjustments from increasing.

According to the embodiment described above, the current adjustment device detects the amplifier 100, the reference current circuit 600 connected in parallel with the amplifier 100, the current flowing through the amplifier 100 and the reference current circuit 600, and A current detection circuit 400 that converts the value of the current into an output voltage, and an adjustment unit that adjusts the current flowing through the amplifier 100 and the reference current circuit 600. Here, the adjustment unit corresponds to, for example, the control circuit unit 300. When a current flows only in the reference current circuit 600 by the control circuit unit 300, the current detection circuit 400 detects the current flowing in the reference current circuit 600 as the reference current I _REF-min and outputs the reference current I _REF− The value of _min is converted to a reference voltage V _REF . Further, when the reference current I _REF-min flows through the reference current circuit 600 and the amplifier 100 by the control circuit unit 300, the current detection circuit 400 determines the value of the reference current I _REF-min flowing through the reference current circuit 600 and the amplifier. The reference voltage V _REF is converted into an updated reference voltage V _REF together with the value of the reference current I _REF-min flowing through the reference voltage V _REF . Further, the control circuit 300 adjusts the current flowing only to the amplifier 100 so that the output voltage of the current detection circuit 400 becomes the updated reference voltage V _REF when the current flows only to the amplifier 100.

According to such a configuration, since the drain current is adjusted stepwise by updating the reference voltage V _REF using the reference current I _REF-min , the sensitivity a of the current detection circuit 400 and the value of V _offset An error caused by non-linear variation can be reduced, and the accuracy of adjusting the drain current can be improved.

  It should be noted that other configurations whose examples are described in the specification of the present application other than these configurations can be omitted as appropriate. That is, if at least these configurations are provided, the effects described above can be produced.

  However, when at least one of the other configurations exemplified in the specification of the present application is appropriately added to the above-described configuration, that is, in the specification of the present application which is not mentioned as the above-described configuration. The same effects can be obtained even when other configurations as shown in FIG.

  Further, according to the embodiment described above, the adaptive array antenna includes the above current adjusting device. According to such a configuration, the characteristics of the individual antenna elements in the adaptive array antenna can be matched with high accuracy, so that the main lobe and the side lobe of the adaptive array antenna can be controlled with high accuracy.

<Modifications of the above-described embodiment>
In the embodiments described above, the materials, materials, dimensions, shapes, relative arrangement relations, or the conditions of implementation of the respective components may be described, but these are all examples. , And is not limited to those described in the specification of the present application.

  Thus, innumerable variations and equivalents, not shown, are envisioned within the scope of the techniques disclosed herein. For example, when modifying, adding or omitting at least one component, or extracting at least one component in at least one embodiment and combining it with components of other embodiments. Shall be included.

  Unless inconsistency arises, "one or more" of the components described as being provided in "one" in the above-described embodiment may be provided.

  Further, each component in the above-described embodiment is a conceptual unit, and one component includes a plurality of structures within the scope of the technology disclosed in this specification. And a case where one component corresponds to a part of a structure, and a case where a plurality of components are provided in one structure.

  Each component in the above-described embodiment includes a structure having another structure or shape as long as the same function is exhibited.

  Further, the description in the specification of the present application is referred to for all purposes related to the present technology, and none of them is admitted to be prior art.

  Further, each component described in the embodiment described above is assumed to be software or firmware, or hardware corresponding thereto, and in both concepts, each component is referred to as a “unit”. Or, it is called a “processing circuit”.

  Reference Signs List 1 antenna, 2 transmission / reception changeover switch, 3 transmission amplifier, 4 reception amplifier, 5a, 5b phase shifter, 6 transmission / reception circuit, 7 baseband signal processing unit, 8, 301 control processing unit, 100, 100B, 101, 102, 103 , 110, 110B, 111, 112, 113, 1n0, 1n0B, 1n1, 1n2, 1n3 amplifier, 200, 201, 202, 210, 211, 212, 2n0, 2n1, 2n2 DAC, 300 control circuit section, 302 memory, 303 Gate setting voltage output section, 400 current detection circuit, 401 current sensor circuit, 402 ADC, 500 power supply for drain bias, 600, 600A reference current circuit, 601, 611 resistance, 602, 612 transistor.

Claims (8)

At least one amplifier through which a current for performing amplification flows;
A reference current circuit connected in parallel with the amplifier, and in which a current flows in parallel with the current flowing through the amplifier;
A current detection circuit that detects the current flowing through the amplifier and the reference current circuit, and converts the value of the current into an output voltage;
When the current flows only in the reference current circuit, the current detection circuit detects the current flowing in the reference current circuit as a first reference current, and determines the value of the first reference current as a first reference current. 1 to the reference voltage,
When the first reference current flows through the reference current circuit and the amplifier, the current detection circuit determines a value of the first reference current flowing through the reference current circuit and the first current flowing through the amplifier. The value is converted into a second reference voltage by adding the value of the reference current,
Adjusting the current flowing only to the amplifier so that the output voltage of the current detection circuit becomes the second reference voltage when the current flows only to the amplifier;
Current adjustment method. The reference current circuit includes a transistor,
When the current flows only in the reference current circuit, and the first reference voltage is output from the current detection circuit, a gate voltage applied to the transistor is a first gate voltage,
The gate voltage applied to the amplifier when the current flows through only the amplifier and the first reference voltage is output from the current detection circuit is a second gate voltage,
When the first gate voltage is applied to the transistor and the second gate voltage is applied to the amplifier, the current detection circuit converts the reference voltage to the second reference voltage. Converting the value of the current flowing through the current circuit and the value of the current flowing through the amplifier into the second reference voltage;
The current adjustment method according to claim 1. The value of the first reference current is a minimum value detectable by the current detection circuit.
The current adjustment method according to claim 1 or 2. The reference current circuit includes a reference current source circuit, and an offset current source circuit connected in parallel with the reference current source circuit,
When the current is passed through the reference current source circuit and the offset current source circuit, the current detection circuit combines the current flowing through the reference current source circuit and the current flowing through the offset current source circuit to generate a current. 2, and the value of the second reference current is converted to a third reference voltage.
When the first reference current is passed through the reference current source circuit and the second reference current is passed through the amplifier, the current detection circuit outputs the first current flowing through the reference current source circuit. Converting the value of the reference current and the value of the second reference current flowing through the amplifier into a fourth reference voltage,
Adjusting the current flowing only to the amplifier so that the output voltage of the current detection circuit becomes the fourth reference voltage when the current flows only to the amplifier;
The current adjustment method according to any one of claims 1 to 3. The amplifier is a multi-stage amplifier,
Adjust the current flowing through the amplifier in order from the front stage of the multi-stage amplifier,
Adjusting the current flowing through the first stage of the multi-stage amplifier;
When adjusting the current flowing through the amplifier of the second stage which is a stage subsequent to the first stage of the multistage amplifier, the amplifier of the first stage has the adjusted current. Is in a state of being washed away,
The current adjustment method according to any one of claims 1 to 4. A plurality of said amplifiers are connected in parallel with each other;
Adjusting the current flowing only to each of the amplifiers so that the output voltage obtained by converting the value of the current flowing only to each of the amplifiers by the current detection circuit is equal among a plurality of the amplifiers;
The current adjustment method according to any one of claims 1 to 5. An amplifier through which a current for performing amplification flows;
A reference current circuit connected in parallel with the amplifier, and in which a current flows in parallel with the current flowing through the amplifier;
A current detection circuit that detects the current flowing through the amplifier and the reference current circuit, and converts the value of the current into an output voltage;
An adjustment unit that adjusts the current flowing through the amplifier and the reference current circuit,
When the current flows only through the reference current circuit by the adjustment unit, the current detection circuit detects the current flowing through the reference current circuit as a first reference current, and Is converted to a first reference voltage,
When the first reference current flows through the reference current circuit and the amplifier respectively by the adjustment unit, the current detection circuit determines the value of the first reference current flowing through the reference current circuit and the current flowing through the amplifier. Converting the value of the first reference current into a second reference voltage,
The adjustment unit adjusts the current flowing only to the amplifier so that the output voltage of the current detection circuit becomes the second reference voltage when the current flows only to the amplifier.
Current regulator. A current regulating device according to claim 7,
Adaptive array antenna.

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