Radio frequency signal acquisition circuit

Abstract

The utility model discloses a radio frequency signal acquisition circuit, comprising a first comparison circuit, the input end of which is connected with a radio frequency load, and the output end of which is connected with the input end of a first amplification circuit; the output end of the first amplifying circuit is connected with the main control circuit; the input end of the conversion circuit is connected with the radio frequency load, and the output end of the conversion circuit is connected with the input end of the second comparison circuit; the input end of the second comparison circuit is connected with the radio frequency load, and the output end of the second comparison circuit is connected with the input end of the second amplification circuit; and the output end of the second amplifying circuit is connected with the main control circuit. According to the application, the first comparison circuit, the first amplification circuit, the conversion circuit, the second comparison circuit and the second amplification circuit convert the radio frequency current signal and the radio frequency voltage signal of the radio frequency load and then output the converted signals to the main control circuit, so that the radio frequency current signal or the radio frequency voltage signal received by the main control circuit is accurate enough; and the phenomenon of signal distortion is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of signal processing, in particular to a radio frequency signal acquisition circuit. Background Art

[0002] As a skin care device, a beauty instrument generally acts on the deep tissues of the skin through radio frequency electromagnetic waves, heats the dermis layer of the skin, and stimulates the generation of new collagen and elastin, so as to achieve the beauty method of tightening the skin; for the radio frequency current signal or radio frequency voltage signal output by the radio frequency load for stimulating the human skin, it is necessary to collect and transmit it back to the main control circuit in real time; in the prior art, the radio frequency current signal or radio frequency voltage signal is directly transmitted back to the main control circuit without any processing, so that the radio frequency current signal or radio frequency voltage signal received by the main control circuit is not accurate enough, and there is a phenomenon of signal distortion. Summary of the Utility Model

[0003] Based on this, in view of the above problems, it is necessary to propose a radio frequency signal acquisition circuit.

[0004] A radio frequency signal acquisition circuit includes:

[0005] A first comparison circuit, with an input end connected to the radio frequency load and an output end connected to the input end of a first amplification circuit, is configured to obtain a reference current signal and a first radio frequency current signal of the radio frequency load, and output a second radio frequency current signal to the first amplification circuit;

[0006] The first amplification circuit, with an output end connected to the main control circuit, is configured to receive the second radio frequency current signal, amplify the second radio frequency current signal, and output it to the main control circuit;

[0007] A conversion circuit, with an input end connected to the radio frequency load and an output end connected to the input end of a second comparison circuit, is configured to obtain a first radio frequency voltage signal of the radio frequency load, convert the first radio frequency voltage signal into a third radio frequency current signal, and output it to the second comparison circuit;

[0008] The second comparison circuit, with an input end connected to the radio frequency load and an output end connected to the input end of a second amplification circuit, is configured to obtain the reference current signal and the third radio frequency current signal of the radio frequency load, and output a fourth radio frequency current signal to the second amplification circuit;

[0009] The second amplification circuit, with an output end connected to the main control circuit, is configured to receive the fourth radio frequency current signal, amplify the fourth radio frequency current signal, and output it to the main control circuit.

[0010] In one embodiment, the first comparison circuit includes: a first operational amplifier, a first resistor, and a second resistor;

[0011] The non-inverting input terminal and the inverting input terminal of the first operational amplifier are both connected to the RF load, and the output terminal of the first operational amplifier is connected to the input terminal of the first amplifying circuit;

[0012] One end of the first resistor is connected to the inverting input terminal of the first operational amplifier, and the other end is connected to the input terminal of the first amplifying circuit;

[0013] The second resistor is connected in parallel with the first resistor.

[0014] In one embodiment, the first comparison circuit further includes: a first Schottky diode;

[0015] The common terminal of the first Schottky diode is connected to the output terminal of the first operational amplifier, the anode of the first Schottky diode is connected to the other end of the first resistor, and the cathode of the first Schottky diode is connected to the other end of the second resistor.

[0016] In one embodiment, the first amplifying circuit includes: a second operational amplifier, a third resistor, and a fourth resistor;

[0017] One end of the third resistor is connected to the other end of the first resistor, and the other end of the third resistor is connected to the inverting input terminal of the second operational amplifier;

[0018] One end of the fourth resistor is connected to the end of the second resistor far from the first operational amplifier, and the other end of the fourth resistor is connected to the non-inverting input terminal of the second operational amplifier;

[0019] The output terminal of the second operational amplifier is connected to the main control circuit.

[0020] In one embodiment, the first amplifying circuit further includes: a fifth resistor and a first capacitor;

[0021] One end of the fifth resistor is connected to the inverting input terminal of the second operational amplifier, and the other end is connected to the output terminal of the second operational amplifier;

[0022] The first capacitor is connected in parallel with the fifth resistor.

[0023] In one embodiment, the conversion circuit includes: a sixth resistor, a seventh resistor, an eighth resistor, a second capacitor, and a second Schottky diode;

[0024] One end of the sixth resistor is connected to the RF load, the other end of the sixth resistor is connected to one end of the seventh resistor, the other end of the seventh resistor is connected to one end of the eighth resistor, the other end of the eighth resistor is connected to one end of the second capacitor, and the other end of the second capacitor is connected to the input terminal of the second comparison circuit;

[0025] The common terminal of the second Schottky diode is connected to one end of the second capacitor close to the eighth resistor, and both the cathode and anode of the second Schottky diode are grounded.

[0026] In one embodiment, the second comparison circuit includes: a third operational amplifier, a ninth resistor, and a tenth resistor;

[0027] The non-inverting input terminal and the inverting input terminal of the third operational amplifier are both connected to the RF load, and the output terminal of the third operational amplifier is connected to the input terminal of the second amplification circuit;

[0028] One end of the ninth resistor is connected to the inverting input terminal of the third operational amplifier, and the other end is connected to the input terminal of the second amplification circuit;

[0029] The tenth resistor is connected in parallel with the ninth resistor.

[0030] In one embodiment, the second comparison circuit further includes: a third Schottky diode;

[0031] The common terminal of the third Schottky diode is connected to the output terminal of the third operational amplifier, the anode of the third Schottky diode is connected to the other end of the ninth resistor, and the cathode of the third Schottky diode is connected to the other end of the tenth resistor.

[0032] In one embodiment, it is characterized in that the second amplification circuit includes: a fourth operational amplifier, an eleventh resistor, and a twelfth resistor;

[0033] One end of the eleventh resistor is connected to the other end of the ninth resistor, and the other end of the eleventh resistor is connected to the inverting input terminal of the fourth operational amplifier;

[0034] One end of the twelfth resistor is connected to the end of the tenth resistor far from the third operational amplifier, and the other end of the twelfth resistor is connected to the non-inverting input terminal of the fourth operational amplifier;

[0035] The output terminal of the fourth operational amplifier is connected to the main control circuit.

[0036] In one embodiment, the second amplification circuit further includes: a thirteenth resistor and a third capacitor;

[0037] One end of the thirteenth resistor is connected to the inverting input terminal of the fourth operational amplifier, and the other end is connected to the output terminal of the fourth operational amplifier;

[0038] The third capacitor is connected in parallel with the thirteenth resistor.

[0039] Implementing the embodiments of the present invention will have the following beneficial effects:

[0040] In this application, a reference current signal and a first radio frequency current signal of the radio frequency load are obtained through a first comparison circuit, and a second radio frequency current signal is output to the first amplification circuit; the first amplification circuit receives the second radio frequency current signal, amplifies the second radio frequency current signal and then outputs it to the main control circuit; a conversion circuit obtains a first radio frequency voltage signal of the radio frequency load, converts the first radio frequency voltage signal into a third radio frequency current signal and then outputs it to the second comparison circuit; the second comparison circuit obtains the reference current signal and the third radio frequency current signal of the radio frequency load, and outputs a fourth radio frequency current signal to the second amplification circuit; the second amplification circuit receives the fourth radio frequency current signal, amplifies the fourth radio frequency current signal and then outputs it to the main control circuit. The first comparison circuit, the first amplification circuit, the conversion circuit, the second comparison circuit and the second amplification circuit in this application convert the radio frequency current signal and the radio frequency voltage signal of the radio frequency load and then output them to the main control circuit, so that the radio frequency current signal or the radio frequency voltage signal received by the main control circuit is accurate enough to avoid signal distortion. Description of the Drawings

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0042] Among them:

[0043] Figure 1 It is a structural block diagram of a radio frequency signal acquisition circuit in an embodiment;

[0044] Figure 2 It is a circuit diagram of a first comparison circuit, a first amplification circuit, a conversion circuit, a second comparison circuit and a second amplification circuit in an embodiment. Detailed Embodiments

[0045] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0046] As a skin care device, a beauty instrument generally acts on the deep tissues of the skin through radio frequency electromagnetic waves, heats the dermis layer of the skin, and stimulates the production of new collagen and elastin, so as to achieve the beauty method of tightening the skin; for the radio frequency current signal or radio frequency voltage signal output by the radio frequency load and used to stimulate the human skin, it needs to be collected in real time and transmitted back to the main control circuit; in the prior art, the radio frequency current signal or radio frequency voltage signal is directly transmitted back to the main control circuit without any processing, so that the radio frequency current signal or radio frequency voltage signal received by the main control circuit is not accurate enough and there is a phenomenon of signal distortion. To solve the above technical problems, the present application provides a radio frequency signal acquisition circuit, as Figure 1 shown, including: a first comparison circuit 10, a first amplification circuit 20, a conversion circuit 30, a second comparison circuit 40 and a second amplification circuit 50, wherein, the input end of the first comparison circuit 10 is connected to the radio frequency load, and the output end is connected to the input end of the first amplification circuit 20, and is used to obtain the reference current signal and the first radio frequency current signal of the radio frequency load, and output a second radio frequency current signal to the first amplification circuit 20; the output end of the first amplification circuit 20 is connected to the main control circuit, and is used to receive the second radio frequency current signal, and amplify the second radio frequency current signal and output it to the main control circuit;

[0047] The input end of the conversion circuit 30 is connected to the RF load, and the output end is connected to the input end of the second comparison circuit 40, which is used to obtain the first RF voltage signal of the RF load, convert the first RF voltage signal into a third RF current signal, and output it to the second comparison circuit 40; the input end of the second comparison circuit 40 is connected to the RF load, and the output end is connected to the input end of the second amplification circuit 50, which is used to obtain the reference current signal and the third RF current signal of the RF load, and output a fourth RF current signal to the second amplification circuit 50; the output end of the second amplification circuit 50 is connected to the main control circuit, which is used to receive the fourth RF current signal, amplify the fourth RF current signal, and output it to the main control circuit. In this application, the first comparison circuit obtains the reference current signal and the first RF current signal of the RF load, and outputs a second RF current signal to the first amplification circuit; the first amplification circuit receives the second RF current signal, amplifies the second RF current signal, and outputs it to the main control circuit; the conversion circuit obtains the first RF voltage signal of the RF load, converts the first RF voltage signal into a third RF current signal, and outputs it to the second comparison circuit; the second comparison circuit obtains the reference current signal and the third RF current signal of the RF load, and outputs a fourth RF current signal to the second amplification circuit; the second amplification circuit receives the fourth RF current signal, amplifies the fourth RF current signal, and outputs it to the main control circuit. The first comparison circuit, the first amplification circuit, the conversion circuit, the second comparison circuit, and the second amplification circuit in this application convert the RF current signal and the RF voltage signal of the RF load and output them to the main control circuit, so that the RF current signal or the RF voltage signal received by the main control circuit is accurate enough to avoid signal distortion.

[0048] In one embodiment, as Figure 2 shown, the first comparison circuit 10 includes: a first operational amplifier U12A, a first resistor R127, and a second resistor R131; wherein, the non-inverting input end and the inverting input end of the first operational amplifier U12A are both connected to the RF load, and the output end of the first operational amplifier U12A is connected to the input end of the first amplification circuit 20; one end of the first resistor R127 is connected to the inverting input end of the first operational amplifier U12A, and the other end is connected to the input end of the first amplification circuit 20; the second resistor R131 is connected in parallel with the first resistor R127.

[0049] In one embodiment, as Figure 2As shown, the first comparison circuit 10 further includes: a first Schottky diode DS5; wherein, the common terminal of the first Schottky diode DS5 is connected to the output terminal of the first operational amplifier U12A, the anode of the first Schottky diode DS5 is connected to the other end of the first resistor R127, and the cathode of the first Schottky diode DS5 is connected to the other end of the second resistor R131.

[0050] In one embodiment, as Figure 2 As shown, the first amplification circuit 20 includes: a second operational amplifier U13A, a third resistor R129, and a fourth resistor R130; wherein, one end of the third resistor R129 is connected to the other end of the first resistor R127, and the other end of the third resistor R129 is connected to the inverting input terminal of the second operational amplifier U13A;

[0051] One end of the fourth resistor R130 is connected to the end of the second resistor R131 far from the first operational amplifier U12A, and the other end of the fourth resistor R130 is connected to the non-inverting input terminal of the second operational amplifier U13A; the output terminal of the second operational amplifier U13A is connected to the main control circuit.

[0052] In one embodiment, as Figure 2 As shown, the first amplification circuit 20 further includes: a fifth resistor R125 and a first capacitor R84; wherein, one end of the fifth resistor R125 is connected to the inverting input terminal of the second operational amplifier U13A, and the other end is connected to the output terminal of the second operational amplifier U13A; the first capacitor R84 is connected in parallel with the fifth resistor R125.

[0053] In one embodiment, as Figure 2 As shown, the conversion circuit 30 includes: a sixth resistor R134, a seventh resistor R135, an eighth resistor R136, a second capacitor C88, and a second Schottky diode DS6; wherein, one end of the sixth resistor R134 is connected to the RF load, the other end of the sixth resistor R134 is connected to one end of the seventh resistor R135, the other end of the seventh resistor R135 is connected to one end of the eighth resistor R136, the other end of the eighth resistor R136 is connected to one end of the second capacitor C88, and the other end of the second capacitor C88 is connected to the input terminal of the second comparison circuit 40; the common terminal of the second Schottky diode DS6 is connected to the end of the second capacitor C88 close to the eighth resistor R136, and both the cathode and anode of the second Schottky diode DS6 are grounded.

[0054] In one embodiment, as Figure 2As shown, the second comparison circuit 40 includes: a third operational amplifier U12B, a ninth resistor R137, and a tenth resistor R140; wherein, the non-inverting input terminal and the inverting input terminal of the third operational amplifier U12B are both connected to the RF load, and the output terminal of the third operational amplifier U12B is connected to the input terminal of the second amplification circuit 50; one end of the ninth resistor R137 is connected to the inverting input terminal of the third operational amplifier U12B, and the other end is connected to the input terminal of the second amplification circuit 50; the tenth resistor R140 is connected in parallel with the ninth resistor R137.

[0055] In one embodiment, as Figure 2 shown, the second comparison circuit 40 further includes: a third Schottky diode DS7; wherein, the common terminal of the third Schottky diode DS7 is connected to the output terminal of the third operational amplifier U12B, the anode of the third Schottky diode DS7 is connected to the other end of the ninth resistor R137, and the cathode of the third Schottky diode DS7 is connected to the other end of the tenth resistor R140.

[0056] In one embodiment, as Figure 2 shown, the second amplification circuit 50 includes: a fourth operational amplifier U13B, an eleventh resistor R138, and a twelfth resistor R141; wherein, one end of the eleventh resistor R138 is connected to the other end of the ninth resistor R137, and the other end is connected to the inverting input terminal of the fourth operational amplifier U13B; one end of the twelfth resistor R141 is connected to the end of the tenth resistor R140 far from the third operational amplifier U12B, and the other end is connected to the non-inverting input terminal of the fourth operational amplifier U13B; the output terminal of the fourth operational amplifier U13B is connected to the main control circuit.

[0057] In one embodiment, as Figure 2 shown, the second amplification circuit 50 further includes: a thirteenth resistor R133 and a third capacitor C89; wherein, one end of the thirteenth resistor R133 is connected to the inverting input terminal of the fourth operational amplifier U13B, and the other end is connected to the output terminal of the fourth operational amplifier U13B; the third capacitor C89 is connected in parallel with the thirteenth resistor R133.

[0058] This application obtains the reference current signal and the first radio frequency current signal of the radio frequency load through the first comparison circuit, and outputs the second radio frequency current signal to the first amplification circuit; the first amplification circuit receives the second radio frequency current signal, amplifies the second radio frequency current signal and outputs it to the main control circuit; the conversion circuit obtains the first radio frequency voltage signal of the radio frequency load, converts the first radio frequency voltage signal into a third radio frequency current signal and outputs it to the second comparison circuit; the second comparison circuit obtains the reference current signal and the third radio frequency current signal of the radio frequency load, and outputs a fourth radio frequency current signal to the second amplification circuit; the second amplification circuit receives the fourth radio frequency current signal, amplifies the fourth radio frequency current signal and outputs it to the main control circuit. The first comparison circuit, the first amplification circuit, the conversion circuit, the second comparison circuit and the second amplification circuit of this application convert the radio frequency current signal and the radio frequency voltage signal of the radio frequency load and output them to the main control circuit, so that the radio frequency current signal or the radio frequency voltage signal received by the main control circuit is accurate enough to avoid signal distortion.

[0059] The above-disclosed are only the preferred embodiments of the present utility model. Of course, the scope of the rights of the present utility model cannot be limited by this. Therefore, equivalent changes made according to the claims of the present utility model still fall within the scope covered by the present utility model.

Claims

1. A radio frequency signal acquisition circuit, characterized in that: include: a first comparison circuit, whose input end is connected to the RF load and whose output end is connected to the input end of the first amplification circuit, and is used to obtain a reference current signal of the RF load and a first RF current signal, and output a second RF current signal to the first amplification circuit; The first amplifier circuit, whose output end is connected to the main control circuit, is used to receive the second radio frequency current signal, and amplify the second radio frequency current signal and then output it to the main control circuit; a conversion circuit, whose input end is connected to the RF load and whose output end is connected to the input end of the second comparison circuit, for acquiring a first RF voltage signal of the RF load, and converting the first RF voltage signal into a third RF current signal and then outputting it to the second comparison circuit; The second comparison circuit has an input end connected to the RF load and an output end connected to the input end of the second amplification circuit, and is used to obtain the reference current signal of the RF load and the third RF current signal, and output a fourth RF current signal to the second amplification circuit; The output end of the second amplifier circuit is connected to the main control circuit, and is used to receive the fourth radio frequency current signal, and amplify the fourth radio frequency current signal and then output it to the main control circuit.

2. The radio frequency signal acquisition circuit according to claim 1, characterized in that: The first comparison circuit comprises: a first operational amplifier, a first resistor and a second resistor; The in-phase input terminal and the inverting input terminal of the first operational amplifier are both connected to the radio frequency load, and the output terminal of the first operational amplifier is connected to the input terminal of the first amplifying circuit; One end of the first resistor is connected to the inverting input terminal of the first operational amplifier, and the other end is connected to the input terminal of the first amplifier circuit; The second resistor is connected in parallel with the first resistor.

3. The radio frequency signal acquisition circuit according to claim 2, characterized in that: The first comparison circuit further includes: a first Schottky diode; The common end of the first Schottky diode is connected to the output end of the first operational amplifier, the anode of the first Schottky diode is connected to the other end of the first resistor, and the cathode of the first Schottky diode is connected to the other end of the second resistor.

4. The radio frequency signal acquisition circuit according to claim 2, characterized in that: The first amplifying circuit comprises: a second operational amplifier, a third resistor and a fourth resistor; One end of the third resistor is connected to the other end of the first resistor, and the other end of the third resistor is connected to the inverting input end of the second operational amplifier; One end of the fourth resistor is connected to an end of the second resistor away from the first operational amplifier, and the other end of the fourth resistor is connected to the non-inverting input end of the second operational amplifier; The output terminal of the second operational amplifier is connected to the main control circuit.

5. The radio frequency signal acquisition circuit according to claim 4, characterized in that: The first amplifying circuit further includes: a fifth resistor and a first capacitor; One end of the fifth resistor is connected to the inverting input terminal of the second operational amplifier, and the other end is connected to the output terminal of the second operational amplifier; The first capacitor is connected in parallel with the fifth resistor.

6. The radio frequency signal acquisition circuit according to claim 1, characterized in that: The conversion circuit includes: a sixth resistor, a seventh resistor, an eighth resistor, a second capacitor and a second Schottky diode; One end of the sixth resistor is connected to the RF load, the other end of the sixth resistor is connected to one end of the seventh resistor, the other end of the seventh resistor is connected to one end of the eighth resistor, the other end of the eighth resistor is connected to one end of the second capacitor, and the other end of the second capacitor is connected to the input end of the second comparison circuit; The common end of the second Schottky diode is connected to an end of the second capacitor close to the eighth resistor, and the cathode and anode of the second Schottky diode are both grounded.

7. The radio frequency signal acquisition circuit according to claim 6, characterized in that: The second comparison circuit comprises: a third operational amplifier, a ninth resistor and a tenth resistor; The in-phase input terminal and the inverting input terminal of the third operational amplifier are both connected to the radio frequency load, and the output terminal of the third operational amplifier is connected to the input terminal of the second amplifying circuit; One end of the ninth resistor is connected to the inverting input terminal of the third operational amplifier, and the other end is connected to the input terminal of the second amplifier circuit; The tenth resistor is connected in parallel with the ninth resistor.

8. The radio frequency signal acquisition circuit according to claim 7, characterized in that: The second comparison circuit further includes: a third Schottky diode; The common end of the third Schottky diode is connected to the output end of the third operational amplifier, the anode of the third Schottky diode is connected to the other end of the ninth resistor, and the cathode of the third Schottky diode is connected to the other end of the tenth resistor.

9. The radio frequency signal acquisition circuit according to claim 7, characterized in that: The second amplifying circuit comprises: a fourth operational amplifier, an eleventh resistor and a twelfth resistor; One end of the eleventh resistor is connected to the other end of the ninth resistor, and the other end of the eleventh resistor is connected to the inverting input end of the fourth operational amplifier; One end of the twelfth resistor is connected to an end of the tenth resistor away from the third operational amplifier, and the other end of the twelfth resistor is connected to the non-inverting input end of the fourth operational amplifier; The output end of the fourth operational amplifier is connected to the main control circuit.

10. The radio frequency signal acquisition circuit according to claim 9, characterized in that: The second amplifying circuit further includes: a thirteenth resistor and a third capacitor; One end of the thirteenth resistor is connected to the inverting input terminal of the fourth operational amplifier, and the other end is connected to the output terminal of the fourth operational amplifier; The third capacitor is connected in parallel with the thirteenth resistor.

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