Driving amplifier with adjustable gain and power amplification circuit

Abstract

The utility model discloses a gain-adjustable driving amplifier and a power amplification circuit, and belongs to the technical field of power electronics. The input matching network and the output matching network are connected with the driving amplification module and are used for performing conjugate matching on source impedance and load impedance of the driving amplification module; and the feedback network is connected with the driving amplification module and is used for adjusting the gain of the driving amplification module according to the output power of the driving amplification module. The feedback network is arranged in the driving amplifier, and the feedback network can adjust the gain of the driving amplifier module according to the output power of the driving amplifier module, so that the technical problem that the gain of the driving amplifier cannot be dynamically adjusted can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of power electronics, in particular to a gain-adjustable driving amplifier and a power amplifier circuit. Background Art

[0002] Currently, the gain of driver amplifiers is fixed, with no way to dynamically adjust the gain to meet the power requirements of different application scenarios. For example, in power amplifier circuits, the driver amplifier often requires a deep bias, which can result in insufficient power delivery. Currently, there is no effective solution to this technical problem.

[0003] It can be seen that how to dynamically adjust the gain of the driving amplifier is a technical problem that needs to be solved urgently by those skilled in the art. Utility Model Content

[0004] In view of this, the purpose of the present invention is to provide a gain-adjustable driver amplifier and a power amplifier circuit to solve the technical problem in the prior art that the gain of the driver amplifier cannot be dynamically adjusted. The specific solution is as follows:

[0005] In order to solve the above technical problems, the utility model provides a gain-adjustable driver amplifier, comprising:

[0006] Drive amplifier module;

[0007] An input matching network and an output matching network connected to the driving amplifier module and used for conjugate matching the source impedance and load impedance of the driving amplifier module;

[0008] A feedback network connected to the driving amplifier module and used to adjust the gain of the driving amplifier module according to the output power of the driving amplifier module.

[0009] Preferably, the feedback network includes: a coupler, a power detection module, a controllable switch, a first resistor, a second resistor, and a signal comparison module for comparing the magnitudes of two signals;

[0010] The input end of the coupler is used to receive the output power of the driving amplification module according to a preset ratio, the output end of the coupler is connected to the input end of the power detection module, the output end of the power detection module is connected to the first input end of the signal comparison module, the second input end of the signal comparison module is used to receive a preset signal, the output end of the signal comparison module is connected to the control end of the controllable switch, the first end of the controllable switch is respectively connected to the first end of the first resistor and the voltage source, the second end of the controllable switch is respectively connected to the second end of the first resistor, the control end of the driving amplification module and the first end of the second resistor, and the second end of the second resistor is grounded.

[0011] Preferably, the coupler is a microstrip line.

[0012] Preferably, the power detection module is specifically a diode;

[0013] The anode of the diode is the input end of the power detection module, and the cathode of the diode is the output end of the power detection module.

[0014] Preferably, the signal comparison module is specifically a comparator;

[0015] The positive input terminal of the comparator is the first input terminal of the signal comparison module, and the negative input terminal of the comparator is the second input terminal of the signal comparison module.

[0016] Preferably, the controllable switch is a triode;

[0017] The base of the transistor is the control end of the controllable switch, the collector of the transistor is the first end of the controllable switch, and the emitter of the transistor is the second end of the controllable switch.

[0018] Preferably, it also includes:

[0019] A state flip module connected to the signal comparison module and used to invert the state of the output signal of the signal comparison module.

[0020] Preferably, the state flip module is specifically an inverter;

[0021] The input end of the inverter is connected to the output end of the signal comparison module, and the output end of the inverter is connected to the control end of the controllable switch.

[0022] Preferably, the driving and amplifying module is specifically a MOS tube;

[0023] Wherein, the gate of the MOS tube is the control end of the driving amplifier module.

[0024] In order to solve the above technical problems, the present invention further provides a power amplifier circuit, including a gain-adjustable driving amplifier as disclosed above.

[0025] Beneficial Effects: The driver amplifier provided by the present invention is provided with a driver amplifier module, an input matching network, an output matching network, and a feedback network. The input matching network and the output matching network are used to conjugately match the source impedance and load impedance of the driver amplifier module, while the feedback network is used to adjust the gain of the driver amplifier module according to the output power of the driver amplifier module. Compared with the prior art, since the driver amplifier is provided with a feedback network and the feedback network can adjust the gain of the driver amplifier module according to the output power of the driver amplifier module, the technical problem of the inability to dynamically adjust the gain of the driver amplifier can be solved.

[0026] Correspondingly, the power amplifier circuit provided by the present invention also has the above beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0028] Figure 1 A structural diagram of a gain-adjustable driver amplifier provided in an embodiment of the present utility model;

[0029] Figure 2 A structural diagram of a feedback network provided by an embodiment of the present utility model;

[0030] Figure 3 This is a structural diagram of another feedback network provided by an embodiment of the present utility model. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] See Figure 1 , Figure 1This is a structural diagram of a gain-adjustable driver amplifier provided by an embodiment of the present utility model, the driver amplifier comprising:

[0033] Driving amplification module 11;

[0034] An input matching network 12 and an output matching network 13 connected to the driving amplifier module 11 and used for conjugate matching the source impedance and load impedance of the driving amplifier module 11;

[0035] A feedback network 14 is connected to the driving amplifier module 11 and is used to adjust the gain of the driving amplifier module 11 according to the output power of the driving amplifier module 11 .

[0036] In this embodiment, a gain-adjustable driver amplifier 100 is provided. The driver amplifier 100 is provided with a driver amplifier module 11, an input matching network 12, an output matching network 13, and a feedback network 14. The driver amplifier module 11 is the core component of the driver amplifier and is mainly used to amplify the drive signal. The input matching network 12 and the output matching network 13 are used to conjugate match the source impedance and load impedance of the driver amplifier module 11 and maximize power transmission. The feedback network 14 is used to adjust the gain of the driver amplifier module 11 according to the output power of the driver amplifier module 11.

[0037] It should be noted that the input matching network 12 and the output matching network 13 are functional modules well known to those skilled in the art. Therefore, in this embodiment, the input matching network 12 and the output matching network 13 are not described in detail.

[0038] In practical applications, the driver amplifier 100 is usually set in the front stage of the power amplifier 200. The driver amplifier 100 and the power amplifier 200 together form a power amplifier circuit, which is usually used in some radio frequency scenarios. Figure 1 In the circuit shown, Rs represents resistance.

[0039] In this embodiment, the feedback network 14 is used to adjust the gain of the driver amplifier module 11 according to the output power of the driver amplifier module 11. In actual applications, the input signal of the feedback network 14 is the output power of the driver amplifier module 11. The output signal of the feedback network 14 is sent to the control terminal of the driver amplifier module 11. The control signal of the driver amplifier module 11 is used to adjust the gain of the driver amplifier module 11, thereby further expanding the power output range of the driver amplifier.

[0040] It should be noted that in actual applications, various circuit modules are used to implement the feedback network 14. In this embodiment, the internal structure of the feedback network 14 is not specifically limited, as long as the circuit module can implement the logical function of the feedback network 14.

[0041] Compared with the prior art, since a feedback network 14 is provided in the driving amplifier 100, and the feedback network 14 can adjust the gain of the driving amplifier module 11 according to the output power of the driving amplifier module 11, the technical problem that the gain of the driving amplifier 100 cannot be dynamically adjusted can be solved.

[0042] Based on the above embodiment, this embodiment further explains and optimizes the technical solution. Figure 2 , Figure 2 This is a structural diagram of a feedback network provided by an embodiment of the present invention. As a preferred embodiment, the feedback network 14 includes: a coupler 101, a power detection module 102, a controllable switch K, a first resistor R1, a second resistor R2, and a signal comparison module U for comparing the magnitudes of two signals;

[0043] In which, the input end of the coupler 101 is used to receive the output power P0 of the driving and amplifying module 11 according to a preset ratio, the output end of the coupler 101 is connected to the input end of the power detection module 102, the output end of the power detection module 102 is connected to the first input end of the signal comparison module U, the second input end of the signal comparison module U is used to receive a preset signal Vref, the output end of the signal comparison module U is connected to the control end of the controllable switch K, the first end of the controllable switch K is respectively connected to the first end of the first resistor R1 and the voltage source VCC, the second end of the controllable switch K is respectively connected to the second end of the first resistor R1, the control end of the driving and amplifying module 11, and the first end of the second resistor R2, and the second end of the second resistor R2 is grounded.

[0044] In this embodiment, the internal structure of the feedback network 14 is specifically described. The feedback network 14 is composed of a coupler 101, a power detection module 102, a controllable switch K, a first resistor R1, a second resistor R2 and a signal comparison module U. Figure 2 In the feedback network shown, Gate represents the control terminal of the driving amplifier module 11. In general, the driving amplifier module 11 is a MOS transistor, and the gate of the MOS transistor is the control terminal of the driving amplifier module 11.

[0045] When the coupler 101 receives the output power P0 of the driver amplifier module 11 according to a preset ratio, it transmits the received power to the power detection module 102. When the power detection module 102 receives the power transmitted by the coupler 101, it transmits the output power of the driver amplifier module 11 to the first input terminal of the signal comparison module U. Thereafter, the signal comparison module U compares the output power of the driver amplifier module 11 with the preset signal Vref and determines whether the output power of the driver amplifier module 11 exceeds the preset signal Vref.

[0046] When the output power of the driver amplifier module 11 exceeds the preset signal Vref, the signal comparison module U outputs a low-level signal, turning off the controllable switch K. In this case, the first resistor R1 connected in parallel with the controllable switch K generates a voltage drop, thereby controlling the voltage at the control terminal of the driver amplifier module 11. As the voltage at the control terminal of the driver amplifier module 11 increases, the gain of the driver amplifier module 11 also increases accordingly.

[0047] When the output power of the driver amplifier module 11 is lower than the preset signal Vref, the signal comparison module U outputs a high-level signal, and the controllable switch K is in the on state. In this case, the first resistor R1 connected in parallel with the controllable switch K is short-circuited and cannot perform a voltage divider. At this time, the voltage at the control terminal of the driver amplifier module 11 remains unchanged, and the gain of the driver amplifier module 11 also remains unchanged.

[0048] Obviously, through the technical solution provided by this embodiment, the feedback network can be used to dynamically adjust the gain of the driving amplifier module.

[0049] As a preferred implementation, the coupler 101 is specifically a microstrip line.

[0050] In this embodiment, the coupler 101 may be configured as a microstrip line. Because the microstrip line is not only low in cost but also occupies a small space, such a configuration can further reduce the structural complexity of the feedback network.

[0051] As a preferred embodiment, the power detection module 102 is specifically a diode;

[0052] The anode of the diode is the input end of the power detection module 102 , and the cathode of the diode is the output end of the power detection module 102 .

[0053] In this embodiment, in order to reduce the structural complexity of the power detection module 102 , the power detection module 102 may be configured as a diode, that is, a diode is used to detect the output power of the power amplification module 11 transmitted by the coupler 101 in real time.

[0054] As a preferred embodiment, the signal comparison module U is specifically a comparator;

[0055] The positive input terminal of the comparator is the first input terminal of the signal comparison module U, and the negative input terminal of the comparator is the second input terminal of the signal comparison module U.

[0056] Since the comparator has a very fast signal response capability compared to other types of signal comparison modules U, in this embodiment, the signal comparison module U can be set as a comparator to increase the gain adjustment speed of the feedback network.

[0057] As a preferred embodiment, the controllable switch K is specifically a triode;

[0058] The base of the transistor is the control end of the controllable switch K, the collector of the transistor is the first end of the controllable switch K, and the emitter of the transistor is the second end of the controllable switch K.

[0059] Because the transistor has the advantages of small size, low cost and fast response speed, when the controllable switch K is set to a transistor, not only the space occupation and design cost of the feedback network can be reduced, but also the working performance of the feedback network can be improved.

[0060] See Figure 3 , Figure 3 This is a structural diagram of another feedback network provided by an embodiment of the present utility model. As a preferred embodiment, it also includes:

[0061] A state flip module M connected to the signal comparison module U and configured to invert the state of the output signal of the signal comparison module U.

[0062] In practical applications, the signal output by the power detection module 102 may not be steep enough, thereby affecting the driving capability of the controllable switch K. Therefore, in order to improve the driving capability of the controllable switch K, a state inversion module M may be connected to the output end of the signal comparison module U. The state inversion module M can be used to invert the state of the output signal of the signal comparison module U, thereby enhancing the strength of the signal received by the controllable switch K.

[0063] As a preferred embodiment, the state flip module M is specifically an inverter;

[0064] The input end of the inverter is connected to the output end of the signal comparison module U, and the output end of the inverter is connected to the control end of the controllable switch K.

[0065] Specifically, the state flip module M can be set as an inverter. Because the inverter has a simple structure, low power consumption, and is easy to integrate with other devices, when the state flip module M is set as an inverter, the structural complexity of the feedback network can be further reduced.

[0066] Correspondingly, an embodiment of the present invention further provides a power amplifier circuit, including a gain-adjustable driving amplifier as disclosed above.

[0067] The power amplifier circuit provided by the embodiment of the present invention has the beneficial effects of the aforementioned gain-adjustable driving amplifier.

[0068] The above description of the disclosed embodiments will enable those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein, but is to be construed in the widest possible manner consistent with the principles and novel features disclosed herein.

Claims

1. A gain-adjustable driver amplifier, characterized in that: include: Drive amplifier module; An input matching network and an output matching network connected to the driving amplifier module and used for conjugate matching the source impedance and load impedance of the driving amplifier module; A feedback network connected to the driving amplifier module and used to adjust the gain of the driving amplifier module according to the output power of the driving amplifier module.

2. The gain-adjustable driver amplifier according to claim 1, wherein: The feedback network includes: a coupler, a power detection module, a controllable switch, a first resistor, a second resistor, and a signal comparison module for comparing the magnitudes of two signals; The input end of the coupler is used to receive the output power of the driving amplification module according to a preset ratio, the output end of the coupler is connected to the input end of the power detection module, the output end of the power detection module is connected to the first input end of the signal comparison module, the second input end of the signal comparison module is used to receive a preset signal, the output end of the signal comparison module is connected to the control end of the controllable switch, the first end of the controllable switch is respectively connected to the first end of the first resistor and the voltage source, the second end of the controllable switch is respectively connected to the second end of the first resistor, the control end of the driving amplification module and the first end of the second resistor, and the second end of the second resistor is grounded.

3. The gain-adjustable driver amplifier according to claim 2, wherein: The coupler is specifically a microstrip line.

4. The gain-adjustable driver amplifier according to claim 2, wherein: The power detection module is specifically a diode; The anode of the diode is the input end of the power detection module, and the cathode of the diode is the output end of the power detection module.

5. The gain-adjustable driver amplifier according to claim 2, wherein: The signal comparison module is specifically a comparator; The positive input terminal of the comparator is the first input terminal of the signal comparison module, and the negative input terminal of the comparator is the second input terminal of the signal comparison module.

6. The gain-adjustable driver amplifier according to claim 2, wherein: The controllable switch is specifically a triode; The base of the transistor is the control end of the controllable switch, the collector of the transistor is the first end of the controllable switch, and the emitter of the transistor is the second end of the controllable switch.

7. The gain-adjustable driver amplifier according to claim 2, wherein: Also includes: A state flip module connected to the signal comparison module and used to invert the state of the output signal of the signal comparison module.

8. The gain-adjustable driver amplifier according to claim 7, characterized in that: The state flip module is specifically an inverter; The input end of the inverter is connected to the output end of the signal comparison module, and the output end of the inverter is connected to the control end of the controllable switch.

9. The gain-adjustable driver amplifier according to claim 2, wherein: The driving and amplifying module is specifically a MOS tube; Wherein, the gate of the MOS tube is the control end of the driving amplifier module.

10. A power amplifier circuit, characterized in that: The invention comprises a gain-adjustable driving amplifier as claimed in any one of claims 1 to 9.

Images