JP2001007653A - High-frequency power amplifier circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a power consumption efficiency when controlling transmission power (decreasing the transmission power) of a mobile station in mobile radio equipment. SOLUTION: Power control data 1 are made correspond to the strength of a signal from a base station and are inputted to a switch control signal conversion section 2 and a bias voltage conversion section 3. When data 1 are 0 dB, a signal from the switch control signal conversion section 2 throws switches 5, 8 to a position of (b). A power amplifier 6 amplifies a transmission signal with 0.5 W amplified by a pre-stage amplifier 4 into a signal with 5 W and transmits the amplified signal to an antenna. When the power control data are -10 dB, the signal from the switch control signal conversion section 2 switches the switches 5, 8 to a position of (c), the signal with 0.5 W from the pre-stage amplifier 4 is transmitted to the antenna via a through-circuit 7, and a signal from the bias voltage conversion section causes a bias voltage of the power amplifier to decrease to turn off a FET to make the power consumption of this stage nearly zero.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency power amplifying circuit, and more particularly to a high frequency power amplifying circuit for improving power consumption efficiency in controlling transmission power of a mobile radio apparatus.

[0002]

2. Description of the Related Art Linear modulation (QPSK = 4-phase modulation, π / 4 Q
In a transmitting section of a mobile radio apparatus using PSK, QAM = quadrature amplitude modulation, etc., for example, as shown in FIG. 4, a base station supplies a variable attenuator 21 and a power amplifier 6 at a stage preceding a PA (power amplifier) unit. Input power control data 1 generated according to the signal strength of
For example, the transmission output power can be varied such as 5 W at the power control of 0 dB and 0.5 W at the power control of -10 dB, and the condition of the positional relationship between the mobile station and the base station (far distance, presence or absence of radio wave obstacle, etc.). However, the receiving sensitivity of the base station was not deteriorated. Then, in order to increase the power consumption efficiency at the time of power control (when the transmission power is reduced), the bias voltage Vgg of the power amplifier 6 is controlled at the time of power control, and the DC input power is reduced from the normal time (power control 0 dB). The power consumption of the power amplifier 6 has been reduced. However, since the transmission signal passes through the power amplifier 6, it is not allowed that the modulation distortion characteristic of the signal is deteriorated by the power amplifier 6, so that the minimum DC input power must be maintained, and the reduction in power consumption is limited. there were.

[0003]

SUMMARY OF THE INVENTION In view of the foregoing, the present invention suspends the operation of the power amplifier during transmission power control, that is, when the transmission output power is set to -10 dB in a normal state,
An object of the present invention is to improve the power consumption efficiency of a transmission unit during power control.

[0004]

In order to achieve the above object, a high-frequency power amplifier circuit according to the present invention is provided in a radio apparatus and includes a pre-amplifier for amplifying a transmission signal and a power amplifier for amplifying a signal from the pre-amplifier. A first switch disposed between the pre-amplifier and the power amplifier to switch a signal from the pre-amplifier to the power amplifier or the through circuit; and a signal from the power amplifier or a signal from the through circuit in conjunction with the first switch A second switch for switching and outputting
A bias voltage conversion unit for converting power control data for controlling transmission power generated based on a received signal into a bias voltage and controlling the bias of the power amplifier,
A switch control signal converter for converting the power control data into a switch control signal and switching between a first switch and a second switch; and a bias voltage converter for biasing the power amplifier based on the power control data. Or the operation is stopped by cutting off the power amplifier by the bias voltage converter, and the first switch and the second switch are switched to the through circuit side by the switch control signal converter.

As the first switch and the second switch, a high-frequency switch circuit for switching a high-frequency signal is used.

That is, the first switch connects the cathode of the first diode and the cathode of the second diode to the signal output terminal of the pre-amplifier via the first capacitor,
Connecting the anode of the diode to the signal input of the power amplifier via the second capacitor, connecting the anode of the second diode to the input of the through circuit via the third capacitor,
A cathode of the first diode and a cathode of the second diode are connected to ground via a high-frequency coil, and a positive voltage or a positive voltage for conducting the first diode from the switch control signal converter to the anode of the first diode via the high-frequency coil via the high-frequency coil A voltage for applying a voltage to make the first diode non-conductive and a voltage or a second diode for making the second diode non-conductive from the switch control signal converter via a high-frequency coil are applied to the anode of the second diode. The second switch is configured to apply a positive voltage for conducting, and the second switch connects the cathode of the third diode and the cathode of the fourth diode to the signal output terminal via the fourth capacitor;
The anode of the third diode is connected to the signal output terminal of the power amplifier via the fifth capacitor, the anode of the fourth diode is connected to the output terminal of the through circuit via the sixth capacitor, and the cathode and the fourth terminal of the third diode are connected. The cathode of the diode is connected to the ground via a high-frequency coil, and the anode of the third diode is connected to the anode of the switch control signal conversion unit via the high-frequency coil for conducting the third diode.
A voltage or a voltage for making the third diode non-conductive is applied, and a voltage or a fourth voltage for making the fourth diode non-conductive from the switch control signal converter via the high-frequency coil to the anode of the fourth diode. It is configured to apply a + voltage for conducting the diode.

A fifth diode in which a cathode is connected to the anode of the first diode of the first switch and the anode is connected to the ground, and a sixth diode in which the cathode is connected to the anode of the second diode and the anode is connected to the ground. A seventh diode in which a cathode is connected to the anode of a third diode of the second switch and the anode is connected to ground; and a seventh diode in which the cathode is connected to the anode of the fourth diode and the anode is connected to ground. Eight diodes may be provided.

In addition, diodes are connected in series to the first diode, the second diode, the third diode, and the fourth diode in the same direction, respectively, and a switch control signal is connected to an anode of a series circuit of the two first diodes. A positive voltage for conducting the two first diodes or a negative voltage for rendering the two first diodes non-conductive is applied from the converter, and the switch control signal conversion is applied to the anode of the series circuit of the two second diodes. Applying a negative voltage for turning off the two second diodes from the unit or a positive voltage for turning on the two second diodes, further comprising the fifth diode, the sixth diode, and the seventh diode. And the eighth diode may be connected in series in the same direction.

The preamplifier amplifies the input transmission signal to a transmission output power set for power control, and the power amplifier is configured to amplify a signal from the preamplifier for power non-control. It is assumed that the transmission output power is amplified.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments with reference to the drawings. FIG. 1 is a block diagram of a main part of an embodiment of a high-frequency power amplifier circuit according to the present invention, which is used in a transmission section of a mobile radio apparatus (mobile station) using a linear modulation method. In the figure, reference numeral 1 denotes power control data generated according to the strength of a signal from a base station. For example, power transmitted to an antenna is 0 W when power control data is 0 dB and 0.5 W when power control data is -10 dB. That's what we do. 2 is a switch control signal converter for converting the power control data 1 to a switch control signal, 3 is a bias voltage converter for converting the power control data 1 to a bias voltage, 4 is a pre-amplifier for amplifying a transmission signal, and 5 is a pre-amplifier. A first switch for switching the signal from the signal 4, a power amplifier 6 for amplifying the signal from the preamplifier 5, a through circuit 7 for bypassing the signal from the preamplifier 5, and a signal 8 from the power amplifier 6 or the through circuit 7. Is a second switch for switching between. The first and second switches 5 and 8 are high-frequency switch circuits configured as shown in FIG.
Correspond to the terminals a, b, and c of the first switch 5 and the second switch 8 in FIG. The power amplifier 6 is an amplifier using the FET 12 as shown in FIG.
Reference numeral 13 denotes a matching circuit for matching input / output impedance, and the high-frequency coil L11 and the capacitor C11 and the high-frequency coil L12 and the capacitor C12 each constitute a decoupling circuit.

Next, the operation of the high-frequency power amplifier circuit according to the present invention will be described. The power control data 1 is data generated by a CPU or the like in accordance with the strength of a signal from a base station. What is the condition of the positional relationship between the mobile station and the base station (far / far, presence / absence of radio wave obstruction, etc.)? However, this is for controlling the transmission power so that the reception sensitivity of the base station does not deteriorate. The pre-amplifier 4 amplifies a transmission signal modulated by a linear modulation method such as QPSK, π / 4 QPSK or QAM so as to have an output of 0.5 W. When the power control data 1 is 0 dB, the switch control signal converter 2 The first switch 5 and the second switch 8 are switched to the “b” side by the signal, input to the power amplifier 6, amplified so that the output becomes 5 W, output to the antenna via the second switch 8, and output the power control data. When 1 is -10 dB, the first switch 5 and the second switch 8 are switched to the c side by the signal from the switch control signal converter 2, and the signal from the preamplifier 4 is output to the antenna via the through circuit 7 and simultaneously. ,
The bias of the FET 12 of the power amplifier 6 is lowered and turned off by the bias voltage from the bias voltage converter 3, and the operation of the FET 12 is stopped, and the power consumption of this stage is reduced to substantially zero.

The power control data 1 is input to the switch control signal converter 2 and the bias voltage converter 3, and when this data is 0 dB, the switch control signal converter 2 applies the power control data to the first switch 5 (shown in FIG. 2). + Voltage to Vcont1 terminal, Vc
A negative voltage is applied to the ont2 terminal, and the first voltage is applied through the high-frequency coil L1.
The diode D1 is turned on (the cathode is grounded by the high-frequency coil L3), the fifth diode D3 is turned off, and the signal from the preamplifier 4 is supplied to the terminal a → the first capacitor C1 → the first diode D1 → the second capacitor C2. → The signal is input to the power amplifier 6 via the terminal b, amplified to 5 W, and output to the antenna via the second switch 8. The second switch 8 applies a positive voltage to the Vcont1 terminal by the switch control signal
A negative voltage is applied to the terminal, the third diode D1 conducts through the high frequency coil L2 (the cathode is grounded by the high frequency coil L3), the seventh diode D3 becomes non-conductive, and the terminal b
→ The path from the fifth capacitor C2 → the third diode D1 → the fourth capacitor C1 → the terminal a is conducted. At this time, the second diode D2 of the first switch 5 becomes non-conductive, the signal from the terminal a is blocked by the second diode D2, the second switch 8 also has the fourth diode D2 non-conductive, and the terminals c and a are connected to each other. Thus, the first switch 5 and the second switch 8 are both switched to the terminal b side. At the same time, the bias voltage from the bias voltage converter 3 has a value that maximizes the amplification of the power amplifier 6, and the signal from the pre-amplifier 4 is amplified to an output of 5W. When the power control data is between 0 dB and −10 dB, the bias voltage is varied by the bias voltage converter 3 and the power amplifier 6 lowers the amplification according to the control data within a range where no linear distortion occurs in the signal. , The output may be reduced.

When the power control data 1 is -10 dB, the switch control signal converter 2 applies a negative voltage to the Vcont1 terminal of the first switch 5, a positive voltage to the Vcont2 terminal, and turns off the first diode D1. The second diode D2 is turned on through the high-frequency coil L2, the sixth diode D4 is turned off, and the signal (0.5 W) from the preamplifier 4 is supplied to the terminal a → the first capacitor C1 → the second.
Diode D2 → third capacitor C3 → input to through circuit 7 via terminal c. At this time, the second switch 8 applies a negative voltage to the Vcont1 terminal by the switch control signal
A positive voltage is applied to the t2 terminal, the third diode D1 becomes non-conductive, the fourth diode D2 becomes conductive via the high frequency coil L2, the eighth diode D4 becomes non-conductive, and the terminal c → the sixth capacitor C3 → the fourth diode D2 → The path from the fourth capacitor C1 to the terminal a is conducted. As a result, both the first switch 5 and the second switch 8 are switched to the terminal c, and the signal (0.5 W) from the pre-amplifier 4 is changed to the first switch 5 →
The signal is output through the through circuit 7 → the second switch 8. The fifth diode D3 of the first switch (the seventh diode D3 of the second switch 8) conducts when a negative voltage is applied to the Vcont1 terminal, and leaks out of the first diode D1 (the same as the third diode D1). This is because the signal is short-circuited by the fifth diode D3 (same as the seventh diode D3).
The sixth diode D4 of the first switch and the eighth diode D4 of the second switch 8 have the same purpose. Alternatively, the same diode may be connected to each diode in series, and the impedance when a reverse bias voltage is applied to the diode may be doubled to suppress signal leakage.
In this case, the positive voltage or the negative voltage applied to the Vcont1 terminal or the Vcont2 terminal is set according to the number of diodes used so that the two diodes are sufficiently conductive or nonconductive.

[0014]

As described above, according to the high-frequency power amplifier circuit of the present invention, the transmission power can be reduced in the normal state (5 W).
When -10 dB (0.5 W) is used, the bias of the FET of the power amplifier is lowered, the operation of the FET is stopped, and the power consumption of this stage is reduced to substantially zero. Power efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a main part block diagram of an embodiment of a high-frequency power amplifier circuit according to the present invention.

FIG. 2 is a circuit diagram of an example of first and second switches (high-frequency switch circuits).

FIG. 3 is an example of a power amplifier.

FIG. 4 is a main part block diagram of one embodiment of a conventional high frequency power amplifier circuit.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 power control data 2 switch control signal converter 3 bias voltage converter 4 pre-amplifier 5 first switch 6 power amplifier 7 second switch 11 matching circuit 12 FET 21 variable attenuator L1 to L3, L11, L12 high frequency coil C1 to C4, C11, C12 Capacitor D1 ~ D4 Diode

Continued on the front page F-term (reference) 5J091 AA01 AA41 CA36 CA81 FA10 FA18 HA09 HA19 HA29 HA33 HA38 KA12 KA23 KA29 SA14 TA01 5J092 AA01 AA41 CA36 CA81 FA10 FA18 GR09 HA09 HA19 HA29 HA33 HA38 KA12 KA23 KA29 SA04 BB05 HH06 HH39 JJ03 JJ04 JJ06 JJ08 LL01 LL11

Claims (8)

[Claims] 1. A pre-amplifier provided in a wireless device for amplifying a transmission signal, a power amplifier for amplifying a signal from the pre-amplifier, and a signal from the pre-amplifier disposed between the pre-amplifier and the power amplifier. A first switch for switching to the power amplifier or the through circuit, a second switch for switching and outputting a signal from the power amplifier or a signal from the through circuit in conjunction with the first switch, and a transmission power generated based on the received signal. A bias voltage converter for converting power control data for control into a bias voltage and controlling the bias of the power amplifier; and a power supply for converting the power control data into a switch control signal for the first switch and the second switch. And a switch control signal converter for performing switching. The bias voltage converter based on the power control data. The bias of the power amplifier is lowered, or the power amplifier is cut off by the bias voltage converter to stop the operation, and the first switch and the second switch are switched by the switch control signal converter to the through circuit side. High-frequency power amplifier circuit that switches to 2. The high-frequency power amplifier circuit according to claim 1, wherein a high-frequency switch circuit for switching a high-frequency signal is used as the first switch and the second switch. 3. The first switch connects a cathode of a first diode and a cathode of a second diode to a signal output terminal of the pre-amplifier via a first capacitor.
The anode of the diode is connected to the signal input terminal of the power amplifier via a second capacitor, the anode of the second diode is connected to the input terminal of the through circuit via a third capacitor, and the cathode of the first diode and the second terminal are connected. The cathode of the two diodes is connected to the ground via a high-frequency coil, and the anode of the first diode is connected to the positive voltage from the switch control signal conversion unit via the high-frequency coil and the first diode is disconnected. Applying a negative voltage to make the second diode from the switch control signal converter non-conductive through a high frequency coil to the anode of the second diode, or applying a negative voltage to make the second diode conductive; , And the second switch is connected to a signal output terminal via a fourth capacitor. The cathode of the third diode is connected to the cathode of the fourth diode, the anode of the third diode is connected to the signal output terminal of the power amplifier via a fifth capacitor, and the anode of the fourth diode is connected to the through-hole via a sixth capacitor. Connected to the output terminal of the circuit, the cathode of the third diode and the cathode of the fourth diode are connected to ground via a high-frequency coil, and the anode of the third diode is connected to the anode via a high-frequency coil. A positive voltage for making the third diode conductive or a negative voltage for making the third diode non-conductive is applied, and the fourth diode from the switch control signal converter is connected to the anode of the fourth diode via a high-frequency coil. Apply a negative voltage for turning off or a positive voltage for turning on the fourth diode High frequency power amplifier circuit of claim 1, wherein consisting configured to. 4. A fifth diode having a cathode connected to an anode of a first diode of the first switch, a fifth diode having an anode connected to ground, a cathode connected to an anode of the second diode, and an anode connected to ground. A sixth diode, wherein a cathode is connected to the anode of the third diode of the second switch, and a cathode is connected to the anode of the fourth diode; and an anode is connected to the ground, 4. The high-frequency power amplifier circuit according to claim 3, further comprising an eighth diode connected to the high-frequency power amplifier. 5. The first diode, the second diode,
To connect the third diode and the fourth diode in series in the same direction, respectively, and to conduct the two first diodes from the switch control signal converter to the anode of the series circuit of the two first diodes. Is applied to the anode of the series circuit of the two second diodes to make the two second diodes from the switch control signal converter non-conductive. 5. The high-frequency power amplifier circuit according to claim 3, wherein a negative voltage for performing the operation or a positive voltage for conducting the two second diodes is applied. 6. The fifth diode, the sixth diode,
A diode is connected in series to the seventh diode and the eighth diode in the same direction, respectively.
A high-frequency power amplifier circuit according to any one of the preceding claims. 7. The high-frequency power amplifier circuit according to claim 1, wherein said pre-amplifier amplifies an input transmission signal to a transmission output power set for power control. 8. The high-frequency power amplifier circuit according to claim 1, wherein the power amplifier amplifies a signal from the pre-amplifier to a transmission output power set for non-power control. .