Power amplifier output standing wave alarm circuit and radio frequency module

Abstract

The utility model relates to a power amplifier output standing wave alarm circuit and a radio frequency module. The power amplifier output standing wave alarm circuit comprises a power amplifier, a switch control circuit, a controller and a coupling circuit. The input end of the power amplifier is used for accessing a radio frequency signal, and the output end of the power amplifier is connected with the control end of the switch control circuit and outputs a radio frequency amplification signal to the switch control circuit; the switch control circuit is used for switching the radio frequency amplification signal to different paths and outputting the radio frequency amplification signal; the coupling circuit comprises a coupler and a processing circuit, the coupler is used for acquiring the radio frequency amplification signal, and the processing circuit is used for processing the radio frequency amplification signal to obtain a judgment signal; the input end of the controller is connected with the coupling circuit, the output end of the controller is connected with the power amplifier, and the controller is used for receiving the judgment signal and controlling the power amplifier to be turned on and turned off according to the judgment signal. The utility model has the technical effects of standing wave anomaly detection and power amplifier protection.

Description

Technical Field

[0001] The utility model is applicable to the technical field of radio frequency circuits, and in particular relates to a power amplifier output standing wave alarm circuit and a radio frequency module. Background Art

[0002] With the development of smart device technology, the circuit design of hardware such as smartphones and tablets is becoming increasingly miniaturized and integrating more functions.

[0003] An existing power amplifier circuit of a smartphone chip is as follows Figure 1 As shown, Figure 1 The middle circuit includes a power amplifier PA, a switch S, and a controller Con. The controller is used to control the power amplifier to turn on and off and provide a suitable bias voltage for the power amplifier. The power amplifier amplifies the input RF signal, and the RF amplified signal amplified by the power amplifier is output through different channels selected by the switch.

[0004] However, the above circuit structure cannot determine whether the standing wave output by the power amplifier is abnormal, cannot provide an alarm signal when the standing wave output by the power amplifier is abnormal, and cannot shut down the power amplifier to provide protection when the standing wave is abnormal. Utility Model Content

[0005] The utility model provides a power amplifier output standing wave alarm circuit and a radio frequency module, aiming to solve the problem that the existing chip power amplifier circuit has no standing wave abnormality detection and control technology.

[0006] To solve the above technical problems, in a first aspect, the present invention provides a power amplifier output standing wave alarm circuit, which includes a power amplifier, a switch control circuit, a controller, and a coupling circuit; the input end of the power amplifier is used to receive a radio frequency signal, the output end of the power amplifier is connected to the control end of the switch control circuit, and outputs a radio frequency amplified signal to the switch control circuit;

[0007] The switch control circuit is used to switch the radio frequency amplified signal to different paths and output them;

[0008] The coupling circuit includes a coupler and a processing circuit, the coupler is used to obtain the radio frequency amplified signal, and the processing circuit is used to process the radio frequency amplified signal to obtain a judgment signal;

[0009] The input end of the controller is connected to the coupling circuit, the output end of the controller is connected to the power amplifier, and the controller is used to receive the judgment signal and control the power amplifier to be turned on and off according to the judgment signal.

[0010] Furthermore, the coupling port and the isolation port of the coupler are connected to each other and coupled to the output end of the power amplifier.

[0011] Furthermore, the processing circuit includes a first resistor, a first diode, a first capacitor, and a second resistor; a first end of the first resistor is connected to the input port of the coupler, and a second end of the first resistor is grounded;

[0012] The positive terminal of the first diode is connected to the output port of the coupler, and the negative terminal of the first diode is connected to the input terminal of the controller;

[0013] A first end of the first capacitor is connected to the cathode end of the first diode, and a second end of the first capacitor is grounded;

[0014] A first end of the second resistor is connected to the first end of the first capacitor, and a second end of the second resistor is grounded.

[0015] Furthermore, the processing circuit also includes a third resistor and a second capacitor, the third resistor is connected in series between the negative end of the first diode and the input end of the controller, the first end of the second capacitor is connected to the input end of the controller, and the second end of the second capacitor is grounded.

[0016] In a second aspect, the present invention further provides a radio frequency module, comprising the power amplifier output standing wave alarm circuit as described in the above embodiment.

[0017] The beneficial effect achieved by the present invention is that a power amplifier output standing wave alarm circuit based on a coupling structure is proposed. The circuit obtains the radio frequency amplified signal output by the power amplifier through the coupling structure, and extracts a judgment signal for judging standing wave abnormality from the radio frequency amplified signal through signal processing, and provides it to a controller for controlling the power amplifier. The controller can turn on and off the power amplifier according to the judgment signal, thereby achieving the technical effect of protecting the power amplifier in the event of standing wave abnormality. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of a power amplifier circuit of a smartphone chip in the prior art;

[0019] Figure 2 The utility model is a circuit structure diagram of a power amplifier output standing wave alarm circuit. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] Please refer to Figure 2 , Figure 2 1 is a circuit structure diagram of a power amplifier output standing wave alarm circuit provided by the present invention. The power amplifier output standing wave alarm circuit 100 includes a power amplifier PA, a switch control circuit 101, a controller Con, and a coupling circuit 102. The input terminal (IN) of the power amplifier PA is used to receive a radio frequency signal. The output terminal of the power amplifier PA is connected to the control terminal of the switch control circuit 101 and outputs a radio frequency amplified signal to the switch control circuit 101.

[0022] The switch control circuit 101 is used to switch the RF amplified signal to different paths and output (OUT);

[0023] The coupling circuit 102 includes a coupler COUP and a processing circuit 1021, wherein the coupler COUP is used to obtain the amplified RF signal, and the processing circuit 1021 is used to process the amplified RF signal to obtain a judgment signal;

[0024] The input end of the controller Con is connected to the coupling circuit 102 , and the output end of the controller Con is connected to the power amplifier PA. The controller Con is configured to receive the determination signal and control the power amplifier PA to be turned on and off according to the determination signal.

[0025] Specifically, in the embodiment of the present invention, the coupling port and the isolation port of the coupler COUP are connected to each other and coupled to the output end of the power amplifier PA.

[0026] The processing circuit 1021 includes a first resistor R1, a first diode D1, a first capacitor C1, and a second resistor R2; a first end of the first resistor R1 is connected to the input port of the coupler COUP, and a second end of the first resistor R1 is grounded;

[0027] The positive terminal of the first diode D1 is connected to the output port of the coupler COUP, and the negative terminal of the first diode D1 is connected to the input terminal of the controller Con;

[0028] A first end of the first capacitor C1 is connected to the cathode end of the first diode D1, and a second end of the first capacitor C1 is grounded;

[0029] A first end of the second resistor R2 is connected to the first end of the first capacitor C1 , and a second end of the second resistor R2 is grounded.

[0030] Specifically, according to the power amplifier output standing wave alarm circuit 100 described in the above embodiment, the coupler COUP is located at the output of the power amplifier PA, and the first resistor R1 ensures the normal operation of the coupler COUP and provides sufficient isolation. When a standing wave anomaly occurs at the output of the switch control circuit 101, the amplified RF signal is reflected back to the output of the power amplifier PA. At this time, the coupler CUOP couples and obtains a portion of the amplified RF signal. The amplified RF signal enters the first diode D1. During the positive half-cycle of the amplified RF signal, the first diode D1 conducts, charging the first capacitor C1 and quickly filling it. During the negative half-cycle of the amplified RF signal, the first diode D1 is cut off, and the first capacitor C1 discharges through the second resistor R2. Over a signal cycle, the first capacitor C1 alternately charges and discharges, outputting an envelope voltage as the judgment signal. The envelope voltage is actually input into the controller Con as an alarm voltage, which can shut down the power amplifier PA, thereby achieving the purpose of protecting the power amplifier.

[0031] Preferably, the processing circuit 1021 also includes a third resistor R3 and a second capacitor C2, the third resistor R3 is connected in series between the negative end of the first diode D1 and the input end of the controller Con, the first end of the second capacitor C2 is connected to the input end of the controller Con, and the second end of the second capacitor C2 is grounded.

[0032] The third resistor R3 and the second capacitor C2 can be regarded as an optimized circuit structure of the processing circuit 1021. According to the above embodiment, the first capacitor C1 alternately charges and discharges to output an envelope voltage as the judgment signal. After the third resistor R3 and the second capacitor C2 are added to the processing circuit 1021, the high-frequency components in the envelope voltage can be further filtered out, and only the low-frequency components after filtering, that is, the low-frequency envelope voltage, are retained. The low-frequency envelope voltage is input into the controller Con as the judgment signal, which makes it easier for the controller Con to determine whether the signal indicates the occurrence of a standing wave anomaly.

[0033] The present invention also provides a radio frequency module, including the power amplifier output standing wave alarm circuit 100 as described in the above embodiment. It can be understood that the radio frequency module using the power amplifier output standing wave alarm circuit 100 of the embodiment of the present invention detects whether a standing wave abnormality occurs in the module based on the circuit structure, and implements power amplifier protection through the power amplifier output standing wave alarm circuit 100.

[0034] The beneficial effect achieved by the present invention is that a power amplifier output standing wave alarm circuit based on a coupling structure is proposed. The circuit obtains the radio frequency amplified signal output by the power amplifier through the coupling structure, and extracts a judgment signal for judging standing wave abnormality from the radio frequency amplified signal through signal processing, and provides it to a controller for controlling the power amplifier. The controller can turn on and off the power amplifier according to the judgment signal, thereby achieving the technical effect of protecting the power amplifier in the event of standing wave abnormality.

[0035] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0036] The embodiments of the present invention are described above in conjunction with the accompanying drawings. What is disclosed is only a preferred embodiment of the present invention. However, the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms and equivalent changes without departing from the scope of protection of the purpose of the present invention and the claims, which are all within the protection of the present invention.

Claims

1. A power amplifier output standing wave alarm circuit, characterized in that: The power amplifier output standing wave alarm circuit includes a power amplifier, a switch control circuit, a controller and a coupling circuit; the input end of the power amplifier is used to receive the radio frequency signal, the output end of the power amplifier is connected to the control end of the switch control circuit, and outputs the radio frequency amplified signal to the switch control circuit; The switch control circuit is used to switch the radio frequency amplified signal to different paths and output them; The coupling circuit includes a coupler and a processing circuit, the coupler is used to obtain the radio frequency amplified signal, and the processing circuit is used to process the radio frequency amplified signal to obtain a judgment signal; The input end of the controller is connected to the coupling circuit, the output end of the controller is connected to the power amplifier, and the controller is used to receive the judgment signal and control the power amplifier to be turned on and off according to the judgment signal.

2. The power amplifier output standing wave alarm circuit according to claim 1, characterized in that: The coupling port and the isolation port of the coupler are connected to each other and coupled to the output end of the power amplifier.

3. The power amplifier output standing wave alarm circuit according to claim 1, characterized in that: The processing circuit includes a first resistor, a first diode, a first capacitor, and a second resistor; a first end of the first resistor is connected to the input port of the coupler, and a second end of the first resistor is grounded; The positive terminal of the first diode is connected to the output port of the coupler, and the negative terminal of the first diode is connected to the input terminal of the controller; A first end of the first capacitor is connected to the cathode end of the first diode, and a second end of the first capacitor is grounded; A first end of the second resistor is connected to the first end of the first capacitor, and a second end of the second resistor is grounded.

4. The power amplifier output standing wave alarm circuit according to claim 3, characterized in that: The processing circuit also includes a third resistor and a second capacitor, the third resistor is connected in series between the negative terminal of the first diode and the input terminal of the controller, the first terminal of the second capacitor is connected to the input terminal of the controller, and the second terminal of the second capacitor is grounded.

5. A radio frequency module, characterized in that: The invention comprises the power amplifier output standing wave alarm circuit according to any one of claims 1 to 4.

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