JP4008451B2 - Cascode connection amplifier circuit and communication apparatus using the same - Google Patents

Description

  The present invention relates to a cascode connection amplifier circuit in which a plurality of transistors are continuously connected (hereinafter referred to as cascode connection) and a communication device (for example, a communication terminal) using the amplifier circuit.

  Conventionally, many cascode-connected amplifier circuits having excellent high-frequency characteristics have been used for amplifier circuits and variable gain amplifier circuits. FIG. 19 shows a cascode connection amplifier circuit described in Patent Document 1. In FIG. The circuit of FIG. 19 has a grounded-emitter bipolar transistor 1903 that receives an input voltage from an input terminal 1901 at its base terminal, a field effect transistor 1904 that is cascode-connected to the bipolar transistor 1903 and has a gate terminal connected to a bias power supply 1905. An output terminal 1902 for extracting an output from the drain terminal of the effect transistor 1904 is provided.

  In general, a cascode-connected amplifier circuit has better high frequency characteristics than a grounded emitter amplifier circuit. In the grounded emitter amplifier circuit, the input capacitance Ci is the sum of the base-emitter capacitance Cbe and the base-collector capacitance Cbc multiplied by (Av + 1) by the mirror effect when the amplification degree is Av. However, in the cascode connection circuit, since the amplification factor Av of the grounded-emitter transistor is 0, the input capacitance Ci is the sum of Cbc and Cbe and is not affected by the mirror effect, so that the frequency characteristics can be improved.

  In the cascode-connected amplifier circuit, when the circuit operation (amplification operation) is stopped, the base terminal of the common emitter bipolar transistor 1903 is controlled by a current or the like, and the operation of the common emitter bipolar transistor 1903 is stopped. The operation of the amplifier circuit was stopped.

  The operation of a general cascode-connected amplifier circuit will be described using the prior art circuit of FIG. By changing the amount of current flowing through the base terminal of the bipolar transistor 1903, the amount of collector current is changed to adjust the gain. In order to stop the amplification operation of the cascode-connected amplifier circuit, the amount of current flowing through the base terminal of the common emitter bipolar transistor 1903 is reduced, and the voltage between the base and the emitter of the bipolar transistor 1903 is made less than the threshold voltage of the transistor. The operation is stopped.

  In the following description, it is expressed that the transistor is operating when the transistor is operating, and that the transistor is operating when the transistor is not operating.

When the grounded-emitter bipolar transistor 1903 is turned off, the potential of the collector terminal of the bipolar transistor 1903 increases. Since the collector terminal of the common emitter bipolar transistor 1903 is connected to the source terminal of the common gate field effect transistor 1904, the collector terminal of the bipolar transistor 1903 and the common terminal of the common gate field effect transistor 1904 are at the same potential. . That is, when the grounded-emitter bipolar transistor 1903 is turned off, the potential of the source terminal of the common-gate field-effect transistor 1904 also increases. When the potential of the source terminal of the grounded-gate field effect transistor 1904 increases, the voltage between the gate and the source of the grounded-gate field-effect transistor 1904 becomes lower than the threshold voltage of the transistor, and the grounded-field field-effect transistor 1904 is turned off.
JP 10-308634 A (publication date: November 17, 1998)

  However, when a large input signal enters the input terminal of the grounded-emitter bipolar transistor 1903, the grounded bipolar transistor 1903 is temporarily turned on by the signal power, and the potential of the collector terminal of the bipolar transistor 1903 decreases. Accordingly, the gate-source voltage of the grounded-gate field effect transistor 1904 becomes equal to or higher than the threshold voltage of the transistor, and the grounded-field field-effect transistor 1904 is turned on. As a result, the cascode connection amplifier circuit that should be turned off temporarily is temporarily turned on, causing a problem that sufficient isolation cannot be obtained.

  Further, when the cascode-connected amplifier circuit is multi-stage like a variable gain amplifier circuit, the following problem occurs. When the circuit of FIG. 19 is multistaged, for example, the circuit of FIG. 20 is obtained. Even if the operation of the grounded-emitter bipolar transistor 2003 is stopped to stop the first-stage cascode-connected amplifier circuit, the voltage is always applied to the gate terminal of the grounded-gate field-effect transistor 2004. It affects the operating state of the connection amplifier circuit. The same applies to the case where the first stage is in the operating state and the second stage is in the non-operating state. That is, there is a problem that signal leakage occurs from each amplification stage, and as a result, the degree of gain suppression and linearity deteriorate.

  The present invention can more reliably stop the operation state of the cascode-connected amplifier circuit, and is not affected by other stages that have stopped operating even when connected in multiple stages, and as a result, gain suppression degree Another object of the present invention is to provide a cascode connection amplifier circuit with good linearity and a communication device (for example, a communication terminal) using the same.

  In order to solve the above problems, a cascode-connected amplifier circuit according to the present invention includes a grounded-emitter bipolar transistor in which a signal is input to a base terminal, a source-grounded field effect transistor in which a signal is input to a gate terminal, a collector In an amplifier circuit in which a grounded base bipolar transistor that outputs a signal from a terminal or a grounded gate field effect transistor that outputs a signal from a drain terminal is cascode-connected, a grounded emitter bipolar transistor or a grounded source field effect transistor is The base current of the base-grounded bipolar transistor or the gate of the gate-grounded field effect transistor is prevented so that the grounded-base bipolar transistor or the gate-grounded field effect transistor does not operate when not operating. It is characterized by controlling the voltage.

  According to the above configuration, the bipolar transistor operates when the voltage between the base and the emitter becomes equal to or higher than the threshold voltage of the transistor, and the field effect transistor operates when the voltage between the gate and the source becomes equal to or higher than the threshold voltage of the transistor. Therefore, in the present invention, the operation of the transistor means that a voltage higher than the threshold voltage is applied between the base and emitter of the bipolar transistor or the gate and source of the field effect transistor, and conversely, the transistor does not operate. It means that a voltage lower than the threshold voltage is applied.

  Therefore, in the above configuration, when the common emitter bipolar transistor or the common source field effect transistor does not operate, the base current of the common base bipolar transistor or the gate voltage of the common gate field effect transistor is controlled. The operation of the grounded bipolar transistor or the gate grounded field effect transistor can be stopped.

  In order to solve the above problems, another cascode-connected amplifier circuit according to the present invention includes a grounded-emitter bipolar transistor in which a signal is input to a base terminal, or a source-grounded field effect transistor in which a signal is input to a gate terminal; In an amplifier circuit in which a grounded base bipolar transistor that outputs a signal from a collector terminal or a grounded gate field effect transistor that outputs a signal from a drain terminal is cascode-connected, a grounded emitter bipolar transistor or a source grounded field effect transistor When the is operating, the voltage across the base terminal of the common base bipolar transistor or the gate terminal of the common gate field effect transistor is higher than the voltage across the common emitter bipolar transistor or common source field effect. When the transistor does not operate, the voltage applied to the gate terminal of the base the base terminal of the ground bipolar transistor or grounded gate field effect transistor, it is characterized in that low.

  According to the above configuration, the voltage applied to the base terminal of the grounded base bipolar transistor or the gate terminal of the grounded gate field effect transistor is operated by the grounded emitter bipolar transistor or the grounded source field effect transistor. By making the voltage lower than the voltage applied at times, the voltage between the base and the emitter of the grounded-base bipolar transistor or the voltage between the gate and the source of the gate-grounded field effect transistor becomes lower than the threshold voltage of the transistor. The operation of the grounded bipolar transistor or the gate grounded field effect transistor can be stopped.

  Still another cascode-connected amplifier circuit according to the present invention provides a grounded-emitter bipolar transistor in which a signal is input to a base terminal or a source-grounded field effect transistor in which a signal is input to a gate terminal. Are connected to the base-grounded bipolar transistor that outputs a signal from the collector terminal or the gate-grounded field effect transistor that outputs a signal from the drain terminal, and the emitter-grounded bipolar transistor or the source-grounded field effect transistor operates. In order to prevent the grounded base bipolar transistor or the grounded gate field effect transistor from operating, the base current of the grounded base bipolar transistor or the gate voltage of the grounded gate field effect transistor is Amplifying section that your is provided with a plurality, it is characterized in that the drain terminal of the collector terminal or gate grounded field-effect transistor, the common base bipolar transistor of each amplifier section are connected to each other.

  According to the above configuration, when the range of various characteristics such as gain and linearity of the amplifier circuit becomes wide, it is difficult to control the entire range with a single stage amplifier circuit, and the range can be increased by connecting an attenuator and a plurality of amplifier circuits. It is necessary to spread. Therefore, by connecting the collector terminal of the base-grounded bipolar transistor of the cascode-connected amplifier section or the drain terminal of the gate-grounded field effect transistor to each other, the amplifier section can be multi-staged, and gain, linearity, etc. The range of various characteristics can be widened.

  In the cascode-connected amplifier circuit, the collector terminal of the common base bipolar transistor or the drain terminal of the common gate field effect transistor of each amplifier section may be connected with a capacitor interposed therebetween.

  According to the above configuration, when the range of various characteristics such as gain and linearity of the amplifier circuit becomes wide, it is difficult to control the entire range with a single stage amplifier circuit, and the range can be increased by connecting an attenuator and a plurality of amplifier circuits. It is necessary to spread. Therefore, by connecting the collector terminal of the grounded-base bipolar transistor of each cascode-connected amplifier circuit or the drain terminal of the gate-grounded field effect transistor with a capacitance between them, the amplifier circuit can be multistaged, and gain and linearity can be achieved. The range of various characteristics such as can be widened.

  In the cascode-connected amplifier circuit, the voltage between the base and the emitter of the common emitter bipolar transistor or the voltage between the gate and the source of the common source field effect transistor becomes less than the threshold voltage of the transistor and does not operate. The voltage between the base and the emitter of the base-grounded bipolar transistor, or the gate ground is controlled by changing the current or voltage of the base terminal of the base-grounded bipolar transistor or the gate terminal of the gate-grounded field effect transistor. You may have the control part which controls the voltage between the gate-source of a field effect transistor to less than the threshold voltage of a transistor.

  According to the above configuration, the base-grounded bipolar transistor before the base-emitter voltage of the common-emitter bipolar transistor or the gate-source voltage of the common-source field-effect transistor becomes less than the threshold voltage of the transistor. By making the voltage between the base and emitter of the transistor or the gate-source voltage of a grounded-gate field effect transistor less than the threshold voltage of the transistor, the characteristics of the amplifier circuit such as gain suppression and linearity can be reduced. Can be improved.

  Moreover, according to the above configuration, the cascode-connected amplifier circuit described in any of the above can be used for a differential circuit, a variable gain amplifier circuit, and the like. Further, since the above-described various characteristics including the high-frequency characteristics of the amplifier circuit are improved, the amplifier circuit can be used for a high-frequency amplifier circuit such as a low-noise amplifier or a power amplifier, and these amplifier circuits can be mounted on a communication terminal. Here, the communication terminal is a terminal that transmits, receives, or transmits / receives radio waves, such as a mobile phone terminal, a stationary type, a vehicle-mounted and mobile TV tuner, a wireless LAN, and the like.

  In order to solve the above-described problem, the cascode-connected amplifier circuit of the present invention is configured such that a signal is input to the control terminal and one conduction terminal is grounded, and the cascode-connected amplifier circuit is cascode-connected to the first transistor. And a transistor control circuit that controls a current flowing through the control terminal of the second transistor or a voltage applied to the second transistor in accordance with a conduction state between the conduction terminals of the first transistor.

  According to the above configuration, for example, the operating state of the second transistor is accurately controlled in accordance with conduction / non-conduction between the collector and emitter of the first transistor or between the source and drain (ON / OFF of the first transistor). Therefore, it is possible to realize a cascode-connected amplifier circuit that has no signal leakage and has sufficient isolation.

  In the above configuration, the transistor control circuit preferably controls the current flowing through the control terminal of the second transistor or the voltage applied thereto so that the conduction terminals of the second transistor are disconnected when the first transistor is not conducting.

  For example, the transistor control circuit may set the voltage applied to the control terminal of the second transistor when the first transistor is not conducting lower than the voltage applied to the control terminal of the second transistor when the first transistor is conducting.

  In the above configuration, the first and second transistors are NPN transistors having a control terminal as a base terminal. The emitter terminal of the first transistor is grounded and the base terminal of the second transistor is grounded in an alternating manner. In addition, the transistor control circuit can be configured to control the base current of the second transistor.

  In the above configuration, the first and second transistors are N-channel field effect transistors having a control terminal as a gate terminal, the source terminal of the first transistor is grounded, and the gate terminal of the second transistor May be grounded in an alternating manner, and the transistor control circuit may be configured to control the gate voltage of the second transistor.

  In the above structure, the first transistor is an NPN bipolar transistor having a control terminal as a base terminal, and the second transistor is an N-channel field effect transistor having a control terminal as a gate terminal. The emitter terminal of one transistor is grounded and the gate terminal of the second transistor is grounded in an alternating manner, and the transistor control circuit can be configured to control the gate voltage of the second transistor.

  In the above structure, the first transistor is an N-channel field effect transistor having a control terminal as a gate terminal, and the second transistor is an NPN bipolar transistor having a control terminal as a base terminal. The source terminal of one transistor is grounded and the base terminal of the second transistor is grounded in an alternating manner, and the transistor control circuit can be configured to control the base current of the second transistor.

  In the present invention, a plurality of the cascode-connected amplifier circuits may be provided, and the amplifier circuits may be connected to each other at the conduction terminal of the second transistor that is not connected to the first transistor.

  According to the above configuration, it is possible to realize a multistage amplifier circuit in which isolation of each amplification stage is ensured.

  In the present invention, it is also possible to provide a plurality of the cascode-connected amplifier circuits, and connect the amplifier circuits to each other via a capacitor at a conduction terminal that is not connected to the first transistor. is there.

  According to the said structure, the isolation of each cascode connection amplification stage can be ensured more reliably.

  In addition, a communication device of the present invention includes the cascode connection amplifier circuit.

  The communication device of the present invention includes the cascode connection amplifier circuit and a received signal strength indicator circuit, and is configured such that control by the transistor control circuit is performed based on a signal from the received signal strength indicator circuit. It is also possible to do.

  By using the cascode-connected amplifier circuit of the present invention, the operation of the grounded base bipolar transistor or the gate-grounded field effect transistor can be stopped, and the amplification operation of the cascode-connected amplifier circuit can be stopped more reliably.

  In addition, when there are a plurality of cascode-connected amplifier circuits of the present invention, by connecting each cascode amplifier circuit directly or by connecting a capacitor, the amplifier circuit can be multistaged and various characteristics such as gain and linearity can be obtained. The characteristics of the amplifier circuit such as gain suppression and linearity can be improved.

  The cascode connection amplifier circuit of the present invention can be replaced with a conventional cascode connection amplifier circuit. In addition, since the variable range of gain and linearity can be increased, there is an effect that it can be used in a variable gain amplifier circuit.

Reference embodiments and embodiments of the present invention will be described with reference to FIGS. 1 to 18 as follows. That is, hereinafter, reference embodiments and embodiments of the present invention will be described with reference to the drawings. In the second and subsequent reference embodiments of the present invention, members having the same functions in the description of the first reference embodiment and the drawings are given the same reference numerals, and descriptions thereof are omitted.

( First reference form )
FIG. 1 shows a circuit diagram of the first reference embodiment of the present invention. FIG. 1 shows a cascode connection amplifier circuit in which the collector terminal of a grounded emitter bipolar transistor 131 (first transistor) and the emitter terminal of a grounded bipolar transistor 132 (second transistor) are connected. A control circuit 111 controls the base current of the bipolar transistor 131. The resistor 151 serves as an AC component block to the control circuit (control unit) 111. The capacitor 161 works as a DC component block to the input terminal 101.

  The control circuit 112 (transistor control circuit) controls the base current of the bipolar transistor 132, and the capacitor 162 grounds the base terminal of the bipolar transistor 132 in an alternating manner. Note that the capacitor 162 can be omitted when the output impedance of the control circuit 112 is sufficiently low. The collector terminal of the bipolar transistor 132 is connected to the output terminal, and is connected to the power source 103 through the resistor 152.

  In the present invention, the control circuit 111 controls the base current of the common emitter bipolar transistor 131 to turn off the common emitter bipolar transistor 131. At that time, the control circuit 112 controls the base current of the common base bipolar transistor 132 (second transistor) to turn off the common base bipolar transistor 132.

  When the base current of the grounded-emitter bipolar transistor 131 is decreased by the control circuit 111 and the voltage between the base and the emitter of the grounded-emitter bipolar transistor 131 becomes lower than the threshold voltage of the transistor, the grounded-emitter bipolar transistor is turned off. The control circuit 112 reduces the base current of the common base bipolar transistor 132 so that the voltage applied to the base terminal of the common base bipolar transistor 132 is equal to the threshold voltage of the transistor. When the voltage is equal to or higher than the voltage and the common emitter bipolar transistor 131 is on, the voltage applied to the base terminal of the common base bipolar transistor 132 is set lower than that of the transistor. By less than value voltage, it is possible to turn off the common base bipolar transistor 132.

  Thereby, the operation of the cascode connection amplifier circuit can be stopped. In particular, if the voltage applied to the base terminal of the common base bipolar transistor 132 is set to 0 V, for example, if no voltage is applied to the base terminal of the common base bipolar transistor 132, the common base bipolar transistor 132 is more reliably turned off. be able to.

  In particular, if the voltage applied to the base terminal of the common base bipolar transistor 132 is set to be lower than the threshold voltage of the transistor, the common emitter bipolar transistor 131 is temporarily turned on, that is, the potential of the collector terminal of the bipolar transistor 131, that is, Even when the emitter terminal potential of the common base bipolar transistor 132 becomes 0V, the common base bipolar transistor 132 is not turned on, and deterioration of isolation can be prevented.

  Further, if the voltage applied to the base terminal of the common base bipolar transistor 132 is lower than the threshold voltage of the transistor, the base-emitter of the common base bipolar transistor 132 is reverse-biased, and the base-emitter capacitance is reduced. Higher isolation is obtained.

  In the circuit of FIG. 1, even when a large input signal momentarily enters the grounded-emitter bipolar transistor 131 when the grounded-emitter bipolar transistor 131 is off, the control circuit 112 causes the grounded bipolar transistor 132 to By keeping the voltage applied to the base terminal sufficiently small, the base-grounded bipolar transistor is not turned on, so that the cascode-connected amplifier circuit does not temporarily operate.

  In FIG. 1, a cascode-connected amplifier circuit is formed by a grounded-emitter bipolar transistor 131 and a grounded-base bipolar transistor 132. However, in cascode-connected amplifier circuits of different circuit types as shown in FIGS. There is a similar effect. 2, 3, and 4, the resistor 152 and the power source 103 in FIG. 1 are omitted.

  FIG. 2 shows a cascode connection circuit in which a common emitter bipolar transistor 231 and a common gate field effect transistor 232 are connected. FIG. 3 shows a cascode-connected amplifier circuit in which a common source field effect transistor 331 and a common gate field effect transistor 332 are connected. FIG. 4 shows a cascode-connected amplifier circuit in which a common source field effect transistor 431 and a common base bipolar transistor 432 are connected.

  1 to 4, the control circuit 111 and the control circuit 112 desirably control the field effect transistor with voltage and the bipolar transistor with current.

  If the cascode-connected amplifier circuit shown in FIGS. 2, 3 and 4 is used, since a grounded-gate or source-grounded field effect transistor is used, the field-effect transistor can be controlled by voltage to reduce current consumption and reduce power consumption. Can be realized. Further, when the power supply voltage cannot be increased as in an integrated circuit, the power supply voltage can be afforded by using a field effect transistor, so that the characteristics are less affected by manufacturing variations and the characteristics are stabilized. In particular, the use of the cascode-connected amplifier circuit of FIG. 2 is most desirable because the amplification factor can be increased because the common emitter bipolar transistor 231 is used.

( Second reference form )
FIG. 5 shows a circuit diagram according to the second embodiment of the present invention. FIG. 5 shows a cascode-connected amplifier circuit formed of a grounded-emitter bipolar transistor 531 and a grounded-gate field effect transistor 532, and a cascode-connected amplifier circuit formed of a grounded-emitter bipolar transistor 533 and a grounded-field field-effect transistor 534. There are two cascode-connected amplifier circuits, and the drain terminals of the grounded gate field-effect transistor 532 and the field-effect transistor 534 are connected.

  In the following description, the cascode-connected amplifier circuit formed by the transistor Q1a (first transistor) and the transistor Q1b (second transistor) shown in the drawings is formed by the first-stage cascode-connected amplifier circuit, the transistor Q2a, and the transistor Q2b. The cascode-connected amplifier circuit is a second-stage cascode-connected amplifier circuit, the cascode-connected amplifier circuit formed by the transistors Qxa and Qxb is an x-th cascode-connected amplifier circuit, and x is defined as an integer.

  When the variable range of various characteristics of the amplifier circuit such as variable gain width and variable width of the linearity becomes wide, it is difficult to control the entire range with a single stage amplifier circuit, and the range is expanded by connecting attenuators and multiple amplifier circuits. There is a need.

  Therefore, by connecting the drain terminals of the grounded-gate field effect transistor 532 and the grounded-gate field effect transistor 534 as shown in FIG. 5, the amplification circuit can be multistaged. Here, the linearity means a third-order input intercept point called IIP3.

  The circuit of FIG. 6 is shown as a comparative example of the present invention. FIG. 6 shows a circuit in which a conventional cascode connection amplifier circuit is multistaged. In FIG. 6, the drain terminals of the gate-grounded field effect transistor 632 and the gate-grounded field effect transistor 634 are connected to each other, and the cascode-connected amplifier circuit is multi-staged. A constant voltage is supplied to the gate terminal using a resistor 651 and a resistor 652 and a resistor 653 and a resistor 654, respectively.

  However, when it is desired to operate a specific amplifier circuit among the amplifier circuits connected in multiple stages, for example, when it is desired to operate the second stage cascode connection amplifier circuit without operating the first stage cascode connection amplifier circuit. For example, a signal leaks from the first-stage cascode-connected amplifier circuit to the second-stage cascode-connected amplifier circuit, and the gain cannot be suppressed and the linearity deteriorates.

  Therefore, in the circuit format as shown in FIG. 5 of the present invention, when it is desired to operate the second-stage cascode connection amplifier circuit without operating the first-stage cascode connection amplifier circuit, the control circuit 511 When the base terminal of the grounded-emitter bipolar transistor 531 is controlled by current and the bipolar transistor 531 is turned off, the control circuit 512 controls the gate terminal of the grounded-field field-effect transistor 532 by voltage so that the grounded-emitter bipolar The voltage applied to the gate terminal of the grounded gate field effect transistor 532 is lower than the voltage applied to the gate terminal of the grounded gate field effect transistor 532 when the type transistor 531 is on, and is less than the threshold voltage of the transistor. Thus, the grounded gate field effect transistor 53 is It is possible to turn off, it is possible to stop the operation of the cascode-connected amplifier circuit of the first stage more reliably.

  The operation of the first stage cascode connection amplifier circuit has stopped more reliably, and there is almost no signal leakage from the first stage cascode connection amplifier circuit to the second stage cascode connection amplifier circuit, so that the gain can be suppressed, Almost no distortion occurs and the linearity is improved.

  In FIG. 5, two cascode-connected amplifier circuits exist, but the same effect can be obtained even when a plurality of cascode-connected amplifier circuits exist as shown in FIG. Further, in FIG. 5, the same kind of cascode connection amplifier circuit is multi-staged, but as shown in FIG. 8, the cascode connection amplifier circuit of the first stage and the second stage cascode connection amplifier circuit have different circuit formats. The same effect can be obtained even if the amplifier circuit is multistaged.

( Third reference form )
FIG. 9 shows a circuit diagram according to the third embodiment of the present invention. FIG. 9 is characterized in that there are two cascode-connected amplifier circuits of FIG. 2 and their drain terminals are connected with a capacitor interposed therebetween. When the cascode-connected amplifier circuits are multistaged, if the amplification factors of the respective cascode-connected amplifier circuits are different, the multistage can be achieved by connecting them with a capacitance interposed therebetween. For example, as shown in FIG. 9, when resistors having different resistance values such as a resistor 951 and a resistor 952 are used to multistage a cascode connection amplifier circuit, the direct current connection between the wiring 901 and the wiring 902 is different, so that direct connection is possible. Can not. Therefore, the DC potentials can be separated by connecting the respective drain terminals with the capacitors interposed therebetween, so that multistages can be achieved.

The multistage circuit also has the effect of the second reference form . In FIG. 9, when the second-stage cascode connection amplifier circuit is operated without operating the first-stage cascode connection amplifier circuit, the control circuit 511 controls the base terminal of the common emitter bipolar transistor 531 with current. When the bipolar transistor 531 is off, the control circuit 512 controls the gate terminal of the grounded-gate field effect transistor 532 with voltage, and when the grounded emitter bipolar transistor 531 is on, the gate-grounded field effect The gate grounded field effect transistor 532 is turned off by making the voltage applied to the gate terminal of the grounded gate field effect transistor 532 lower than the voltage applied to the gate terminal of the transistor 532 to be lower than the threshold voltage of the transistor. The first stage It can stop operation of the code-connected amplifier circuit more reliably.

  The operation of the first stage cascode connection amplifier circuit has stopped more reliably, and there is almost no signal leakage from the first stage cascode connection amplifier circuit to the second stage cascode connection amplifier circuit, so that the gain can be suppressed, Almost no distortion occurs and the linearity is improved.

  In FIG. 9, two cascode-connected amplifier circuits exist, but the same effect can be obtained even if two or more cascode-connected amplifier circuits exist. In FIG. 9, the same type of cascode connection amplifier circuit is multi-staged, but the circuit formats of the cascode connection amplifier circuits at each stage may be different from each other.

( First embodiment)
FIG. 10 shows a circuit diagram for explaining the first embodiment. In FIG. 10, there are six cascode-connected amplifier circuits of FIG. 2 and their drain terminals are connected. The bipolar transistors 1031, 1033, 1035, 1037, 1039, and 1041 having a common emitter are connected to a control circuit (control unit). ) Is controlled by current. The operating cascode-connected amplifier circuit stage is switched depending on the voltage to be controlled, and the variable range of various characteristics of the amplifier circuit such as gain and linearity is widened.

  In addition, each of the field-effect transistors 1032, 1034, 1036, 1038, 1040, and 1042 that are grounded on the gate is also controlled with a voltage by another control circuit. When connecting multiple cascode-connected amplifier circuits, as shown above, the operating emitter-grounded bipolar transistor or gate-grounded field effect transistor is controlled by the control circuit with current or voltage and operated. By more reliably stopping the operation of the cascode connection amplifier circuit other than the cascode connection amplifier circuit stage, there is almost no signal leakage from the non-operating cascode connection amplifier circuit to the cascode connection amplifier circuit to be operated. Suppression is possible, almost no distortion occurs, and linearity is improved.

A circuit as shown in FIG. 11 is conceivable as an example of a circuit for controlling the grounded emitter bipolar transistor used in the circuit of FIG. 10 with a current. FIG. 11 shows a bias circuit for supplying a current to the common emitter bipolar transistor of each cascode-connected amplifier circuit.
A current mirror circuit including a field effect transistor 1110 and a field effect transistor 1111 converts the current into a sink current of the field effect transistor 1111. The source terminals of the field effect transistor 1112 and the field effect transistor 1113 are connected to the drain terminal of the field effect transistor 1111 to form a differential circuit.

  The drain terminals of the field effect transistor 1113 are connected to the source terminals of the field effect transistor 1114 and the field effect transistor 1115, respectively, and similarly form a differential circuit. Similarly, five stages of differential circuits are configured. The gate terminals of the field effect transistors 1113, 1115, 1117, 1119, and 1121 on one side of each differential circuit are connected to a power source 1102 that applies a control voltage. In addition, the gate terminals of the other field effect transistors 1112, 1114, 1116, 1118, and 1120 of each differential circuit not connected to the power source 1102 are connected to a reference voltage generation circuit including resistors 1152 to 1157. It is connected.

  Next, the operation of the circuit of FIG. 11 will be described. When the reference voltage V67 generated by the resistors 1156 and 1157 is higher than the control voltage, that is, when the control voltage is sufficiently low, in the differential circuit configured by the field effect transistor 1112 and the field effect transistor 1113 Since the field effect transistor 1114 is turned off and the field effect transistor 1113 is turned on, all the current flows into the field effect transistor 1113.

  The current flowing through the field effect transistor 1113 is folded back by a current mirror circuit composed of the field effect transistor 1131 and the field effect transistor 1132, and a current as much as the current flowing into the field effect transistor 1112 is connected to the terminal. It flows to 1186. The current flowing to the terminal 1186 flows to the terminal 1086 connected to the base terminal of the common emitter bipolar transistor 1041 of the sixth stage cascode connection amplifier circuit, and becomes the base current of the common emitter bipolar transistor 1041.

  When the control voltage is increased and the control voltage and the reference voltage V67 become equal, the currents flowing in the field effect transistor 1112 and the field effect transistor 1113 become equal to each other. At this time, when the reference voltage V56 generated by the resistor 1155 and the resistor 1156 is compared with the control voltage, the reference voltage V56 is higher, so that the differential circuit configured by the field effect transistor 1114 and the field effect transistor 1115 , The field effect transistor 1115 is turned off and the field effect transistor 1114 is turned on, so that the current flowing through the field effect transistor 1113 flows through the field effect transistor 1114.

  The current flowing through each field effect transistor 1113, 1114 is folded back by a current mirror circuit composed of the field effect transistor 1133 and the field effect transistor 1134, and the amount is the same as that of each field effect transistor 1113, 1114. Current flows to the terminal 1185. When the control voltage and the reference voltage V67 are equal, the amounts of current flowing through the terminal 1185 and the terminal 1186 are equal to each other. Since the total amount of the folded current is the same as the amount of current sucked by the field effect transistor 1111, the amount of current flowing through the terminal 1186 is decreased by increasing the control voltage.

  As the control voltage is further increased, the current flowing through the field effect transistor 1112 further decreases, and most of the current flows through the field effect transistor 1113. Similarly, when the control voltage is increased, the control voltage and the reference voltage are compared, and the current flows through the field effect transistor having the higher voltage. By changing the control voltage, each of the terminals 1181 to 1186 is supplied. The amount of current that flows changes. The currents flowing through the terminals 1181 to 1186 flow to the terminals 1081 to 1086 shown in FIG. 10, and become the base currents of the cascode connection amplifier circuits at the respective stages. Therefore, by changing the control voltage, it is possible to switch the operating cascode-connected amplifier circuit stage of FIG.

  The circuit for controlling the grounded-emitter bipolar transistor of FIG. 10 has been described above. Next, the circuit for controlling the gate-grounded field effect transistor used in the circuit of FIG. 10 with a voltage will be described. As an example, a circuit as shown in FIG. 12 can be considered. FIG. 12 shows a bias circuit for supplying a voltage to the gate-grounded field effect transistor of each cascode connection amplifier circuit.

  The basic operation of the circuit is the same as that of the circuit of FIG. A difference from the circuit of FIG. 11 is that the current is converted into a voltage by using each of the resistors 1258 to 1269 after being turned back by a current mirror circuit. The converted voltage is applied to the terminals 1091 to 1096 shown in FIG. 10, and is a voltage applied to the gate terminal of each cascode-connected amplifier circuit. Since the basic operation is the same as the circuit of FIG. 11, the voltage applied to the gate-grounded field effect transistor of the cascode-connected amplifier circuit shown in FIG. 10 is switched at each cascode-connected amplifier circuit stage by changing the control voltage.

  The circuit shown in FIG. 10 controls the common emitter bipolar transistor and the common gate field effect transistor with current and voltage by the control circuit shown in FIG. 11 and FIG. The circuits shown in FIGS. 11 and 12 form a differential circuit with n-type field effect transistors, but may be formed with p-type field effect transistors as shown in FIGS. 11 to 14 are configured by n-type or p-type field effect transistors, but may be configured by bipolar transistors.

  In FIG. 10, the control circuit for the grounded-emitter bipolar transistor or the grounded-gate field effect transistor may be controlled by a separate power source, but the grounded-emitter bipolar transistor and the grounded-gate field effect transistor are controlled in relation to each other. For this purpose, it is better to share the power supply 1102 of the control circuit.

  FIG. 15 shows changes of the base current of the common emitter bipolar transistor shown in FIG. 10 and the voltage applied to the gate terminal of the common gate field effect transistor with respect to the control voltage. As the control voltage Va changes to Vb, but Va <Vb, the maximum value of the base current of the common emitter bipolar transistor changes to I6, I5, I4, I3, I2, and I1.

  Here, I1 to I6 correspond to the base currents of the first-stage cascode-connected amplifier circuit to the sixth-stage cascode-connected amplifier circuit, respectively. This indicates that the operation of the cascode connection amplifier circuit is switched from the first-stage cascode connection amplifier circuit to the sixth-stage cascode connection amplifier circuit as the control voltage Va changes to Vb. Similarly, as the control voltage Va changes from Vb, the maximum value of the voltage applied to the gate terminal of the common-gate field effect transistor also changes to V6, V5, V4, V3, V2, and V1. Here, V1 to V6 correspond to gate voltages applied from the first-stage cascode-connected amplifier circuit to the sixth-stage cascode-connected amplifier circuit, respectively.

  Vth shown in FIG. 15 is a threshold voltage of the gate-grounded field effect transistor. When the voltage applied to the gate terminal of the grounded-gate field effect transistor becomes less than Vth, the grounded-gate field effect transistor is turned off.

  In the circuit of FIG. 10, the operating cascode-connected amplifier circuit is switched by the control voltage, and the range of various characteristics of the amplifier circuit such as gain and linearity is increased. If the base current of the grounded-emitter bipolar transistor that is turned on is reduced, the current density is reduced, which causes distortion. Then, when switching to the next-stage grounded-emitter bipolar transistor with distortion, the linearity of IIP3 and the like deteriorates.

  Therefore, before the distortion occurs in the grounded emitter bipolar transistor, the gate terminal of the grounded field effect transistor is controlled to turn off the grounded field effect transistor, thereby stopping the operation of the cascode-connected amplifier circuit. Is less likely to occur.

  For example, consider the case where the operation is switched from the second-stage cascode connection amplifier circuit to the first-stage cascode connection amplifier circuit in FIG. The control circuit shown in FIG. 11 operates the second-stage cascode connection amplifier circuit by maximizing the base current of the second-stage cascode connection amplifier circuit.

  Next, when switching from the second-stage cascode-connected amplifier circuit to the first-stage cascode-connected amplifier circuit, the control voltage is increased to increase the current flowing through the terminal 1181 of the control circuit shown in FIG. By reducing the current, the base current of the grounded-emitter bipolar transistor 1033 of the second-stage cascode-connected amplifier circuit is reduced, and the base current of the grounded-emitter bipolar transistor 1031 of the first-stage cascode-connected amplifier circuit is increased. The second-stage cascode connection amplifier circuit is switched to the first-stage cascode connection amplifier circuit.

  However, when the base current of the common emitter bipolar transistor 1033 of the second-stage cascode-connected amplifier circuit is reduced, the current density is reduced and distortion occurs. Therefore, before the distortion occurs, the control terminal shown in FIG. 12 controls the gate terminal of the grounded-gate field effect transistor 1034 of the second-stage cascode-connected amplifier circuit to turn off the grounded-field field effect transistor 1034. Since the gate-grounded field effect transistor 1034 is turned off, the operation of the second-stage cascode connection amplifier circuit is stopped, and the occurrence of distortion can be suppressed.

  FIG. 16 shows changes in the base current of the common emitter bipolar transistor and the voltage applied to the gate terminal of the common gate field effect transistor with respect to the control voltage at that time. By changing the control voltage Vc to Vd (Vc <Vd), the base current I2 of the common emitter bipolar transistor 1033 of the second-stage cascode-connected amplifier circuit is reduced, and the common-emitter bipolar transistor of the first-stage cascode-connected amplifier circuit is reduced. The base current I1 of 1031 is increased.

  At this time, if I2 is reduced, distortion occurs. Therefore, when the control voltage becomes Vd, the voltage V2 applied to the gate terminal of the gate-grounded field effect transistor 1034 of the second-stage cascode-connected amplifier circuit is changed to the transistor The threshold voltage Vth is set to less than the threshold voltage Vth to turn off the grounded-gate field effect transistor 1034 to suppress the occurrence of distortion. Since the gate-grounded field effect transistor 1034 is turned off, the second-stage cascode-connected amplifier circuit is turned off and only the first-stage cascode-connected amplifier circuit is turned on, so that the linearity of the circuit is improved.

  In FIG. 16, when the control voltage is increased, the gate-grounded field effect transistor is turned off in conjunction with the reduction of the base current of the common emitter bipolar transistor of the cascode-connected amplifier circuit at the stage before switching. Conversely, as shown in FIG. 17, the gate-grounded field effect transistor can be turned off when the base current of the common emitter bipolar transistor of the cascode-connected amplifier circuit of the next stage to be switched is increased.

  Such on / off timing may be set by detecting the base current or the gate voltage, or may be set by a desired constant time lag if the timing is substantially constant.

  In FIG. 17, consider a case where the operation is switched from the sixth-stage cascode connection amplifier circuit to the fifth-stage cascode connection amplifier circuit. By changing the control voltage Ve to Vf (Ve <Vf), the base current I6 of the common emitter bipolar transistor 1041 of the sixth-stage cascode-connected amplifier circuit is reduced, and the common emitter bipolar transistor of the fifth-stage cascode-connected amplifier circuit. The base current I5 of 1039 is increased.

  When the base current I5 increases, the current density of the common emitter bipolar transistor 1039 of the fifth-stage cascode-connected amplifier circuit is still small, which causes distortion. Therefore, until the base current I5 is increased and the control voltage Vf is reached, the voltage V5 applied to the gate terminal of the gate-grounded field effect transistor 1040 of the fifth-stage cascode-connected amplifier circuit is set to be less than the threshold voltage Vth of the transistor. The ground field effect transistor 1040 is turned off to suppress the generation of distortion.

  Since the gate-grounded field effect transistor 1040 is turned off, the fifth-stage cascode-connected amplifier circuit is turned off and only the sixth-stage cascode-connected amplifier circuit is turned on, so that the linearity of the circuit is improved.

  16 and 17 consider the case where the control voltage is raised, but consider the case where the control voltage is lowered. For example, in FIG. 16, when switching the operation from the first-stage cascode-connected amplifier circuit to the second-stage cascode-connected amplifier circuit, the control voltage is lowered and the emitter-grounded bipolar of the first-stage cascode-connected amplifier circuit. The base current I1 of the type transistor 1031 is reduced, and the base current I2 of the common emitter bipolar transistor 1033 of the second-stage cascode-connected amplifier circuit is increased. After that, the same idea as described in FIG. 17 can be made.

  When the base current I2 increases, the current density of the common emitter bipolar transistor 1033 of the second-stage cascode-connected amplifier circuit is still small, which causes distortion. Therefore, until the base current I2 is increased and the control voltage Vd is reached, the voltage V2 applied to the gate terminal of the gate-grounded field effect transistor 1034 of the second-stage cascode-connected amplifier circuit is made less than the threshold voltage Vth of the transistor, The ground field effect transistor 1034 is turned off to suppress the generation of distortion.

  Since the gate-grounded field effect transistor 1034 is turned off, the second-stage cascode-connected amplifier circuit is turned off and only the first-stage cascode-connected amplifier circuit is turned on, so that the linearity of the circuit is improved.

  In FIG. 10, there are six cascode-connected amplifier circuits. However, if there are two or more cascode-connected amplifier circuits and they are multistaged, the same effect is obtained. In FIG. 10, cascode connection amplifier circuits of the same circuit type are multistaged, but cascode connection amplifier circuits of different circuit types may be multistaged.

In the circuit diagrams used in the description of the first to third reference embodiments and the first embodiment, a cascode-connected amplifier circuit is formed using an npn bipolar transistor and an n-type field effect transistor. Alternatively, a p-type field effect transistor and a p-type field effect transistor may be used. Further, a common source field effect transistor may be used instead of the common emitter bipolar transistor. Further, a common base bipolar transistor may be used instead of the common gate field effect transistor.

  The base of the common emitter bipolar transistor and the gate of the common source field effect transistor are connected to the control circuit after being connected to the resistor, but instead of the resistor, a coil, a diode, a field effect transistor, or a bipolar transistor is connected. Etc. may be used. For example, a circuit such as a coil, a diode, or a transistor can be used instead of the resistor 151 in FIG. Further, although the resistor 151 is used as the load, a coil or the like may be used instead of the resistor. For example, a coil or the like may be used instead of the resistor 553 in FIG. Further, although the emitter terminal of the common emitter bipolar transistor and the source terminal of the common source field effect transistor are directly grounded, they may be grounded after connecting a resistor or a coil to the emitter terminal and the source terminal.

In the first to third reference embodiments and the first embodiment, the bipolar transistor refers to an npn bipolar transistor, a pnp bipolar transistor, an IGBT (insulated gate bipolar transistor), and the like, and a field effect transistor refers to a MOSFET ( A metal-oxide-semiconductor field effect transistor), MESFET (metal-semiconductor field effect transistor), MISFET (metal-insulator-semiconductor field effect transistor), JFET (junction field effect transistor), etc. are said.

( Second embodiment)
In terminals that transmit or receive radio waves, such as mobile phone terminals, stationary types, in-vehicle and mobile TV tuners, and wireless LANs, there are situations where the received power changes significantly or the transmission power must be adjusted. Therefore, it is necessary to vary various characteristics such as gain and linearity in the amplifier circuit. If the variable range is narrow, a single-stage amplifier circuit such as a single-ended or differential amplifier circuit may be possible, but the cascode-connected amplifier circuit of the present invention can be replaced with a conventional cascode-connected amplifier circuit, so It can be used as an amplifier circuit.

  In addition, since the cascode-connected amplifier circuit of the present invention has good gain controllability, distortion can be suppressed and linearity such as IIP3 can be increased, so that the variable range of various characteristics such as gain and linearity of the amplifier circuit can be increased. When it is desired to increase the width, it is preferable to use a multi-stage amplifier circuit. In particular, in a receiving circuit, high gain is required when reception power is low, and linearity such as no distortion caused by a high reception signal is important when reception power is high.

FIG. 18 shows a block diagram of the second embodiment in the case where the cascode connection amplifier circuit of the present invention is used in a low noise amplifier of a portable terminal which is an example of a communication terminal. In the mobile phone shown in FIG. 18, FILTER indicates a filter 10, LNA indicates a low noise amplifier 12, MIX indicates a mixer 14, VCO indicates a voltage control oscillator 16, and DEMOD indicates a demodulation circuit 18. A signal that enters from the antenna 20 passes through a filter 10 such as a low-pass filter or a band-pass filter, extracts only a desired frequency, and enters a low-noise amplifier 12.

  When the cascode connection amplifier circuit of the present invention is used for a low noise amplifier, a signal is output to a circuit connected next, such as the mixer 14, while maintaining high linearity. Further, the cascode-connected amplifier circuit of the present invention can be used for a low-noise amplifier composed of a single-ended circuit or a differential amplifier circuit, and can be used for a mobile phone terminal, a stationary type, a vehicle-mounted type, and a portable television equipped with a low-noise amplifier. When used for a terminal that transmits or receives radio waves, such as a tuner and a wireless LAN, a highly sensitive terminal can be realized.

  Further, the cascode connection amplifier circuit of the present invention can be used not only for portable or mobile terminals but also for stationary terminals. For example, the cascode connection amplifier circuit of the present invention can be used as a low noise amplifier in a stationary television. When watching a TV on a stationary TV, a taxi that generates a radio wave different from the TV frequency passes near the house, and a strong radio wave such as a taxi radio enters the TV antenna, causing temporary distortion. However, when the cascode connection amplifier circuit of the present invention is used, it is difficult to be distorted by such a temporary strong radio wave, so that a highly sensitive terminal can be realized.

  In addition, when the cascode connection amplifier circuit of the present invention is used as a low noise amplifier for a stationary television or a portable television, when a strong radio wave is generated by a mobile phone or the like when watching the television, the radio wave is tuned to the tuner. However, when the cascode connection amplifier circuit of the present invention is used, it is difficult to distort with such a temporary strong radio wave, so it is possible to realize a highly sensitive terminal. It is.

  The cascode-connected amplifier circuit and the variable gain amplifier circuit according to the present invention have a cascode-connected amplifier in which a plurality of transistor elements that are output by controlling the flow of electricity that is input according to a current value or a voltage value with respect to a control terminal are cascode-connected to each other. It can be said that the circuit is provided with a control circuit (control unit / transistor control circuit) for controlling a current value or a voltage value for a control terminal of at least one transistor element other than the transistor element connected to the input terminal.

  Moreover, as said control, what is based on a received signal strength index value (RSSI) is mentioned. RSSI is a DC voltage value obtained by, for example, detecting an envelope of a received signal, which is band-limited by an IF filter, in a mobile phone having an IQ modulator / demodulator or the like. The RSSI is input to a baseband processing circuit and used to generate each control signal.

  The cascode connection amplifier circuit according to the present invention is excellent in high frequency characteristics and can improve various characteristics of the amplifier circuit such as gain suppression and linearity, thereby enabling communication in the communication field such as a communication terminal (for example, a portable terminal) and the computer field. It can be used suitably.

It is a circuit diagram of the cascode connection amplifier circuit in the first reference form of the present invention. It is a circuit diagram of another example of the cascode connection amplifier circuit of said 1st reference form . It is a circuit diagram of another example of the cascode connection amplifier circuit of the first reference form . It is a circuit diagram of another example of the cascode connection amplifier circuit of the first reference form . It is a circuit diagram of the cascode connection amplifier circuit in the 2nd reference form of this invention. It is a circuit diagram of another example of the cascode connection amplifier circuit of said 2nd reference form . It is a circuit diagram of another example of the cascode connection amplifier circuit of the second reference embodiment . It is a circuit diagram of another example of the cascode connection amplifier circuit of the second reference embodiment . It is a circuit diagram of the cascode connection amplifier circuit in the 3rd reference form of this invention. It is a circuit diagram of a cascode connection amplifier circuit in a first embodiment of the present invention. FIG. 3 is a circuit diagram of a control circuit that supplies current to a grounded-emitter bipolar transistor of the cascode-connected amplifier circuit according to the first embodiment of the present invention. FIG. 3 is a circuit diagram of a control circuit that supplies a voltage to a gate terminal of a grounded-gate field effect transistor of the cascode-connected amplifier circuit according to the first embodiment of the present invention. It is a circuit diagram of another example of the control circuit for supplying current to the common emitter bipolar transistor of the cascode-connected amplifier circuit according to the first embodiment of the present invention. It is a circuit diagram of another example of the control circuit which supplies a voltage to the gate terminal of the gate grounded field effect transistor of the cascode connection amplifier circuit in the first embodiment of the present invention. (A) is a graph showing a change in current flowing through the base terminal of the bipolar transistor in the circuit diagram of FIG. 10, and (b) is a change in voltage applied to the gate terminal of the field effect transistor in the circuit diagram of FIG. It is the graph showing. (A) is a graph showing a change in current flowing through the base terminal of the bipolar transistor in the circuit diagram of FIG. 10, and (b) is a change in voltage applied to the gate terminal of the field effect transistor in the circuit diagram of FIG. FIG. 4 is a diagram illustrating switching of an operating cascode connection amplifier circuit. (A) is a graph showing a change in current flowing through the base terminal of the bipolar transistor in the circuit diagram of FIG. 10, and (b) is a change in voltage applied to the gate terminal of the field effect transistor in the circuit diagram of FIG. FIG. 6 is a graph illustrating another example of switching of an operating cascode connection amplifier circuit. It is a block diagram of the portable terminal which concerns on this invention. It is a circuit diagram of the conventional cascode connection amplifier circuit. It is the circuit diagram which multistaged the conventional cascode connection amplifier circuit.

Explanation of symbols

101, 1901, 2001 Input terminal 102, 1902, 2002 Output terminal 103, 1101 Power supply voltage terminal 1102 Control voltage power supply terminal 111, 112, 511-514, 711-718 Control circuit 131, 231, 531, 533, 631, 633 731,733,735,737,831,833,1031,1033,1035,1037,1039,1041,1903,2003,2005 Common emitter bipolar transistor 232,332,532,534,632,634,732,734, 736, 738, 832, 1032, 1034, 1036, 1038, 1040, 1042, 1904, 2004, 2006 Grounded gate field effect transistor 132, 432 Grounded base bipolar transistor 331, 4 1 source grounded field effect transistors 1110 to 1121, 1210 to 1221 n-type field effect transistors 1131 to 1142, 1231 to 1242, 1310 to 1321, 1410 to 1421 p-type field effect transistors 151, 152, 551 to 553, 651 -654,751-755,951,952,1051,1151-1157,1251-1269,1351-1357,1451-1469 Resistor 161,162,561-564,761-768,961,1061-11072,2009 Capacitor 1091 -1096 Voltage control circuit connection terminals 1081 to 1086 Current control circuit connection terminals 1181 to 1186 and 1381 to 1386 Common emitter bipolar transistor connection terminals 1291 to 1296, 1481 to 14 6 common gate field effect transistor connected terminals 1905,2007,2008 bias power supply

Claims (5)

A signal is input from a grounded bipolar bipolar transistor that receives a signal to the base terminal, or a source grounded field effect transistor that receives a signal to the gate terminal, a grounded bipolar transistor that outputs a signal from the collector terminal, or a signal from the drain terminal. In the amplification circuit in which the grounded gate field effect transistor to be output is cascode-connected,
When the grounded emitter bipolar transistor or the source grounded field effect transistor does not operate, the grounded base bipolar transistor or the gate grounded field effect transistor does not operate.
Control the base current of the common base bipolar transistor or the gate voltage of the common gate field effect transistor ,
Before the voltage between the base and the emitter of the common emitter bipolar transistor or the voltage between the gate and the source of the common source field effect transistor becomes lower than the threshold voltage of the transistor and becomes inoperative,
By controlling the base terminal of the grounded base bipolar transistor or the gate terminal of the grounded gate field effect transistor by changing the current or the voltage, the voltage between the base and the emitter of the grounded base bipolar transistor or the grounded gate electric field is controlled. A cascode-connected amplifier circuit comprising a control unit that controls a voltage between a gate and a source of an effect transistor to be lower than a threshold voltage of the transistor . A signal is input from a grounded bipolar bipolar transistor that receives a signal to the base terminal, or a source grounded field effect transistor that receives a signal to the gate terminal, a grounded bipolar transistor that outputs a signal from the collector terminal, or a signal from the drain terminal. In the amplifier circuit in which the grounded gate field effect transistor to be output is cascode-connected,
When the grounded emitter bipolar transistor or the source grounded field effect transistor is operating, than the voltage applied to the base terminal of the grounded base bipolar transistor or the gate terminal of the grounded gate field effect transistor,
When the common emitter bipolar transistor or the common source field effect transistor does not operate, the voltage applied to the base terminal of the common base bipolar transistor or the gate terminal of the common gate field effect transistor is low .
Before the voltage between the base and the emitter of the common emitter bipolar transistor or the voltage between the gate and the source of the common source field effect transistor becomes lower than the threshold voltage of the transistor and becomes inoperative,
By controlling the base terminal of the common base bipolar transistor or the gate terminal of the common gate field effect transistor by changing the current or voltage, the voltage between the base and the emitter of the common base bipolar transistor or the common gate electric field is controlled. A cascode-connected amplifier circuit comprising a control unit that controls a voltage between a gate and a source of an effect transistor to be lower than a threshold voltage of the transistor . A signal is input from a grounded bipolar bipolar transistor that receives a signal to the base terminal, or a source grounded field effect transistor that receives a signal to the gate terminal, a grounded bipolar transistor that outputs a signal from the collector terminal, or a signal from the drain terminal. When the grounded field effect transistor to be output is cascode-connected and the grounded emitter bipolar transistor or the source grounded field effect transistor does not operate, the grounded base bipolar transistor or the gate grounded field effect transistor does not operate. A plurality of amplifying units for controlling the base current of the common base bipolar transistor or the gate voltage of the common gate field effect transistor;
The collector terminal of the base-grounded bipolar transistor of each amplification unit or the drain terminal of the gate-grounded field effect transistor is connected to each other ,
Before the voltage between the base and the emitter of the common emitter bipolar transistor or the voltage between the gate and the source of the common source field effect transistor becomes lower than the threshold voltage of the transistor and becomes inoperative,
By controlling the base terminal of the common base bipolar transistor or the gate terminal of the common gate field effect transistor by changing the current or voltage, the voltage between the base and the emitter of the common base bipolar transistor or the common gate electric field is controlled. A cascode-connected amplifier circuit comprising a control unit that controls a voltage between a gate and a source of an effect transistor to be lower than a threshold voltage of the transistor . A signal is input from a grounded bipolar bipolar transistor that receives a signal to the base terminal, or a source grounded field effect transistor that receives a signal to the gate terminal, a grounded bipolar transistor that outputs a signal from the collector terminal, or a signal from the drain terminal. When the grounded field effect transistor to be output is cascode-connected and the grounded emitter bipolar transistor or the source grounded field effect transistor does not operate, the grounded base bipolar transistor or the gate grounded field effect transistor does not operate. A plurality of amplifying units for controlling the base current of the common base bipolar transistor or the gate voltage of the common gate field effect transistor;
The collector terminal of the base-grounded bipolar transistor of each amplification unit or the drain terminal of the gate-grounded field effect transistor is connected across a capacitor ,
Before the voltage between the base and the emitter of the common emitter bipolar transistor or the voltage between the gate and the source of the common source field effect transistor becomes lower than the threshold voltage of the transistor and becomes inoperative,
By controlling the base terminal of the grounded base bipolar transistor or the gate terminal of the grounded gate field effect transistor by changing the current or the voltage, the voltage between the base and the emitter of the grounded base bipolar transistor or the grounded gate electric field is controlled. A cascode-connected amplifier circuit comprising a control unit that controls a voltage between a gate and a source of an effect transistor to be lower than a threshold voltage of the transistor . A communication apparatus using the cascode connection amplifier circuit according to claim 1 .

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