Impedance adjusting circuit

Abstract

The embodiment of the utility model discloses an impedance adjusting circuit. The circuit comprises an input end, a reactance adjusting module and a resistance adjusting module. The reactance adjusting module comprises a first potentiometer and a reactance element, the first potentiometer adjusts the grounding performance of the reactance element so as to change the reactance resistance value of the reactance element, and then the imaginary part of impedance is adjusted. The resistance adjusting module comprises a second potentiometer, and the second potentiometer adjusts the resistance impedance connected to the circuit so as to adjust the real part of the impedance. According to the embodiment of the utility model, through the above structure, the adjustment circuit is formed by using relatively simple components, and the real part and the imaginary part of the impedance of the circuit are adjusted, so that the circuit obtains a relatively good impedance adjustment effect.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit regulation, in particular to an impedance regulation circuit. Background Art

[0002] In RF and microwave circuits, in order to achieve good signal matching, improve signal transmission efficiency, achieve maximum power transmission efficiency and improve circuit stability, impedance needs to be adjusted accordingly. Impedance (Z = R + jX) is a measure of the degree of resistance of a circuit or system to the flow of current. It is a complex number consisting of a real part and an imaginary part. Among them, the real impedance is usually called resistive impedance, represented by the symbol R, and the imaginary impedance is usually called reactive impedance, represented by the symbol X.

[0003] In the prior art, only a potentiometer is used as a load to adjust the circuit. The potentiometer can only change the real part R of the impedance but cannot change the imaginary part X, resulting in the circuit being unable to obtain an ideal impedance. Utility Model Content

[0004] In view of this, an object of the present invention is to provide an impedance adjustment circuit for adjusting the real part and the imaginary part of the impedance.

[0005] The utility model provides an impedance adjustment circuit, which comprises: an input end; a reactance adjustment module, comprising a first potentiometer and a reactance element, wherein the first end of the first potentiometer is connected to the first end of the reactance element, and the second end of the first potentiometer is grounded; and a resistance adjustment module, comprising a second potentiometer, wherein the first end of the second potentiometer is connected to the input end, and the second end of the second potentiometer is grounded.

[0006] Furthermore, the second end of the reactance element is connected to the input end.

[0007] Furthermore, the third end of the second potentiometer is suspended.

[0008] Furthermore, the third end of the second potentiometer is connected to an open line, and the open line has a second adhesive section at the third end away from the second potentiometer, and the length of the second adhesive section is less than or equal to the total length of the open line.

[0009] Furthermore, the reactance element is connected to the third end of the second potentiometer.

[0010] Furthermore, the input end has a first adhesive section.

[0011] Furthermore, the third end of the first potentiometer is suspended.

[0012] Furthermore, the first end of the second potentiometer is an adjustable end.

[0013] Furthermore, the second end of the first potentiometer is an adjustable end.

[0014] Furthermore, the reactance element is a capacitor or an inductor.

[0015] The embodiment of the utility model discloses an impedance adjustment circuit, which includes an input end, a reactance adjustment module and a resistance adjustment module. The reactance adjustment module includes a first potentiometer and a reactance element, and the first potentiometer adjusts the grounding performance of the reactance element to change the reactance resistance of the reactance element, thereby adjusting the imaginary part of the impedance. The resistance adjustment module includes a second potentiometer, and the second potentiometer adjusts the resistance impedance of the circuit connected to itself, thereby adjusting the real part of the impedance. Through the above structure, the embodiment of the utility model uses relatively simple components to form an adjustment circuit, adjusts the real part and imaginary part of the impedance of the circuit, so that the circuit obtains a better impedance adjustment effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other purposes, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0017] Figure 1 This is a circuit diagram of an impedance adjustment circuit provided in Embodiment 1 of the present utility model;

[0018] Figure 2 It is a circuit diagram of another impedance adjustment circuit provided in Embodiment 1 of the present utility model;

[0019] Figure 3 This is a circuit diagram of an impedance adjustment circuit provided in Embodiment 2 of the present utility model;

[0020] Figure 4 It is a circuit diagram of another impedance adjustment circuit provided in Embodiment 2 of the present utility model;

[0021] Figure 5 This is a circuit diagram of an impedance adjustment circuit provided in Embodiment 3 of the present utility model;

[0022] Figure 6 This is a circuit diagram of another impedance adjustment circuit provided in Embodiment 3 of the present utility model;

[0023] Figure 7 This is a circuit diagram of an impedance adjustment circuit provided in Embodiment 4 of the present utility model;

[0024] Figure 8 This is a circuit diagram of another impedance adjustment circuit provided in Embodiment 4 of the present utility model.

[0025] Marking Description:

[0026] RF1-input terminal; GND-ground; R1-first potentiometer; 5-first end of the first potentiometer; 6-second end of the first potentiometer; 7-third end of the first potentiometer; R2-second potentiometer; 8-first end of the second potentiometer; 9-second end of the second potentiometer; 10-third end of the second potentiometer; C1-capacitor; L1-inductor; 1-first adhesive section; 2-second adhesive section; 3-open line; 4-ground via. DETAILED DESCRIPTION

[0027] The present application is described below based on embodiments, but the present application is not limited to these embodiments. In the detailed description of the present application below, some specific details are described in detail. It is possible for those skilled in the art to fully understand the present application without the description of these details. In order to avoid confusing the essence of the present application, known methods, processes, flows, components and circuits are not described in detail.

[0028] In addition, persons of ordinary skill in the art will appreciate that the drawings provided herein are for illustration purposes and are not necessarily drawn to scale.

[0029] Unless otherwise clearly defined and specified, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0030] Unless the context clearly requires otherwise, the words "include", "comprising" and similar words throughout the application should be interpreted as including rather than exclusive or exhaustive; that is, the meaning is "including but not limited to".

[0031] In the description of this application, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0032] Impedance plays an important role in circuit analysis and design. It is used to describe the characteristics of the circuit, transmission power, signal matching and impedance matching, etc. By adjusting the impedance, signal transmission, matching and control can be achieved to meet the performance requirements of the circuit. Impedance can be expressed in complex form as Z = R + jX, where R is the real impedance, X is the imaginary impedance, and j is the imaginary unit. The real part of the impedance represents the degree of resistance of the circuit to the current, reflecting the influence of the active components in the circuit on the current. The imaginary part of the impedance represents the phase delay or advance of the circuit to the current, reflecting the influence of the passive components in the circuit on the current.

[0033] The embodiment of the utility model provides a regulating circuit, which regulates the real part and imaginary part of the impedance through a relatively simple structure. The regulating circuit includes an input terminal RF1, a reactance regulating module and a resistance regulating module. The reactance regulating module regulates the reactance impedance (imaginary part of the impedance) of the circuit, and the resistance regulating module regulates the resistance impedance (real part of the impedance) of the circuit, thereby adjusting the impedance of the circuit, and then making the impedance of the circuit meet the requirements.

[0034] The reactance adjustment module includes a first potentiometer R1 and a reactance element, and the reactance element can be one of a capacitor C1 and an inductor L1. The first potentiometer R1 has a resistor and a moving contact (adjustable end), and the resistor has two contact points (fixed ends). The adjustable end of the first potentiometer R1 is grounded, and the two fixed ends of the first potentiometer R1 are respectively connected in the circuit. When the adjustable end of the first potentiometer R1 is adjusted, the resistance value in the circuit does not change. The reactance element is connected in parallel with the first potentiometer R1. When the adjustable end of the first potentiometer R1 is adjusted, the grounding performance of the reactance element changes, so that the corresponding value of the reactance element changes, thereby realizing the change of the imaginary part of the impedance of the matching network circuit. When the reactance element is a capacitor C1, the capacitor C1 is separated by an insulating medium (dielectric) between two conductors. When a voltage is applied to the two conductors of the capacitor C1, the charge will accumulate in the dielectric between the conductors to form an electric field, thereby storing energy. When the resistance from one of the conductors of capacitor C1 to the ground is changed, the equivalent capacitance value and reactance value of the capacitor will change. When the reactance element is an inductor L1, the inductor L1 is composed of a conductor coil. When current passes through, a magnetic field will be generated around the inductor L1, thereby storing electrical energy. When the resistance from the inductor L1 to the ground is changed, the resonant frequency and resonance characteristics of the circuit will be affected, thereby causing the equivalent capacitance value of the circuit to change and the reactance value to change. That is, by adjusting the adjustable end of the first potentiometer R1, the imaginary part of the circuit with the reactance adjustment module can be adjusted. The reactance adjustment module provided by the embodiment of the utility model has a relatively simple structure and low cost. Only the first potentiometer R1 and the ordinary capacitor C1 or inductor L1 are set, and the capacitor C1 and the inductor L1 themselves cannot be adjusted. When adjusting the adjustable end of the first potentiometer R1, the resistance value of the circuit will not change, and only the grounding performance of the reactance element is changed to achieve the change of the reactance impedance, so that the impedance adjustment circuit has higher reliability and better adjustment convenience.

[0035] The resistance adjustment module includes a second potentiometer R2, which has a resistor body and a moving contact (adjustable end), and the resistor body has two contact points (fixed ends). The adjustable end of the second potentiometer R2 is connected to one of the fixed ends in the circuit, and the other fixed end is grounded. By applying voltage simultaneously on both sides of a fixed end and an adjustable end of the second potentiometer R2 connected in the circuit, current will flow through the second potentiometer R2, and according to Ohm's law, the current will generate a voltage drop inside the second potentiometer R2. Adjusting the position of the adjustable end will change the size of the resistor body of the second potentiometer R2 connected to the circuit, thereby changing the equivalent resistance of the second potentiometer R2, and then changing the voltage distribution at both ends of the second potentiometer R2. That is, by adjusting the adjustable end of the second potentiometer R2, the real part of the circuit with the reactance adjustment module can be adjusted.

[0036] Figure 1is a circuit diagram of a regulating circuit provided in Embodiment 1 of the present utility model, such as Figure 1 As shown, the reactance element is a capacitor C1, which is connected between the input terminal RF1 and the first end 5 of the first potentiometer R1, the first end of the capacitor C1 is connected to the first end 5 of the first potentiometer R1, and the second end of the capacitor C1 is connected to the input terminal RF1. The third end 7 of the first potentiometer R1 is suspended, and can also be connected to other elements as needed. The second end 6 of the first potentiometer R1 is an adjustable end, and the adjustable end of the first potentiometer R1 is grounded. When the adjustable end of the first potentiometer R1 is adjusted, the grounding performance of the capacitor C1 changes, so that the equivalent capacitance value of the capacitor C1 changes, and then the reactance impedance (i.e., the imaginary part of the impedance) of the circuit is changed. The first end 8 of the second potentiometer R2 is an adjustable end, and the adjustable end of the second potentiometer R2 is connected to the input terminal RF1, the second end 9 of the second potentiometer R2 is grounded, and the third end 10 of the second potentiometer R2 is suspended. When the adjustable end of the second potentiometer R2 is adjusted, the resistor connected to the second potentiometer R2 changes, thereby changing the resistance impedance (i.e., the real part of the impedance) of the circuit. In one embodiment, the third end 10 of the second potentiometer R2 is connected to the open line 3. The open line 3 can form a microstrip capacitor, and the equivalent capacitance value of the microstrip capacitor formed by the open line 3 can be adjusted by changing one or more of the length, width, or dielectric constant between the open line 3 and the ground GND of the open line 3, thereby adding a capacitor to the circuit at a lower cost.

[0037] Figure 2 is a circuit diagram of another impedance adjustment circuit provided in Embodiment 1 of the present utility model, such as Figure 2 As shown, the reactance element is an inductor L1, which is connected between the input terminal and the first terminal 5 of the first potentiometer R1, the first terminal of the inductor L1 is connected to the first terminal 5 of the first potentiometer R1, and the second terminal of the inductor L1 is connected to the input terminal RF1. Figure 2 The rest of the circuit structure is the same as Figure 1 The circuits shown are exactly the same and will not be described again here.

[0038] Figure 5-Figure 8 is the circuit diagram, Figure 5-Figure 8 Taking the microstrip circuit as an example, it is easy to understand that the circuit can also be a radio frequency circuit. The area with oblique fill lines in the figure is the adhesive part, that is, glue is dripped on this area. The area with dotted fills in the figure is the metal sheet of the pin of the device. The pins of different devices can be connected by at least partially overlapping. The figure also uses straight lines to represent the edge of the circuit board, and multiple circular ground vias 4 are set around the circuit board. When the pin of the device is set around the ground via 4, the pin is grounded.

[0039] Figure 5 This is a circuit diagram of an impedance adjustment circuit provided by the third embodiment of the utility model Figure 5The circuit shown is Figure 1 The circuit shown has exactly the same number of circuit elements and connection methods. It should be noted that when glue is applied on the surface of the microstrip line, the impedance value at the microstrip line where glue is applied will be reduced because the dielectric constant of the glue is greater than the dielectric constant of the air. Embodiment 3 A first adhesive section 1 is provided on the input terminal RF1, and the first adhesive section 1 is glue applied on the microstrip line of the input terminal RF1. After the current flows through the area where the first adhesive section 1 is provided at the input terminal RF1, it flows to the first end 8 of the second potentiometer R2 and the second end of the capacitor C1. By adjusting the material, shape and specific position of the first adhesive section 1, the equivalent capacitance and equivalent resistance of the circuit having the first adhesive section 1 can be changed. Specifically, the first adhesive section 1 forms an additional dielectric layer on the input terminal RF1, and the dielectric layer increases the dielectric constant between the input terminal RF1 and the ground plane. Since the capacitance is proportional to the dielectric constant, the first adhesive section 1 increases the equivalent capacitance value at that location. The presence of the first adhesive section 1 will change the electromagnetic field distribution of the input terminal RF1, thereby affecting the equivalent inductance there. That is, the first adhesive section 1 can change the equivalent capacitance and equivalent inductance of the circuit, thereby affecting the imaginary part of the impedance of the circuit. The third end 10 of the second potentiometer R2 of the third embodiment is connected to the open line 3, and the second adhesive section 2 is arranged on the open line 3, and the second adhesive section 2 is glued on the microstrip line of the open line 3. The open line 3 with the second adhesive section 2 has the same properties as the input terminal RF1 with the first adhesive section 1, and can also change the equivalent capacitance and equivalent inductance of the circuit, thereby affecting the imaginary part of the impedance of the circuit. In the process of setting the circuit, the reactance impedance of the circuit can be adjusted by setting the first adhesive section 1 on the input terminal RF1 and / or setting the second adhesive section 2 on the open line 3. It should be noted that, in order to ensure the normal operation of the circuit, the first adhesive section 1 is set away from the second end of the capacitor C1 and the first end 8 of the second potentiometer R2, and the length of the first adhesive section 1 is less than the total length of the input end RF1; the second adhesive section 2 is set away from the third end 10 of the second potentiometer R2, and the length of the second adhesive section 2 is less than or equal to the total length of the open line 3. The glue for dispensing can be any glue with a dielectric constant greater than the dielectric constant of air, and the glue can be selected according to actual use to make the first adhesive section 1 and the second adhesive section 2. When a significant adjustment effect is required, glue with a larger dielectric constant can be used to dispense glue on the microstrip line.

[0040] Figure 6 : is a circuit diagram of another impedance adjustment circuit provided in Embodiment 3 of the present utility model. Figure 6 The circuit shown is Figure 2 The circuit shown has exactly the same number of circuit components and connection methods. Figure 6 The circuit shown also has Figure 5The first adhesive section 1 and / or the second adhesive section 2 in the circuit shown, the arrangement position and function of the first adhesive section 1 and the second adhesive section 2 are similar to those of Figure 5 The current flows through the area where the first adhesive section 1 is set at the input terminal RF1 and then flows to the first end 8 of the second potentiometer R2 and the second end of the inductor L1. It should be noted that in order to ensure the normal operation of the circuit, the first adhesive section 1 is set away from the second end of the inductor L1 and the first end 8 of the second potentiometer R2.

[0041] Figure 3 is a circuit diagram of an impedance adjustment circuit provided in Embodiment 2 of the present utility model, such as Figure 3 As shown, the reactance element is a capacitor C1, and the capacitor C1 is connected between the third end 10 of the second potentiometer R2 and the first end 5 of the first potentiometer R1. The first end 8 of the second potentiometer R2 is connected to the input end RF, the second end 9 of the second potentiometer R2 is grounded, the third end 10 of the second potentiometer R2 is connected to the second end of the capacitor C1, and the adjustable end of the second potentiometer R2 is the first end 8 of the second potentiometer R2 connected to the input end RF. When the adjustable end of the second potentiometer R2 is adjusted, the resistance between the adjustable end and the third end 10 of the second potentiometer R2 will change, thereby changing the resistance impedance (i.e., the real part of the impedance) of the circuit. The third end 10 of the second potentiometer R2 is connected to the second end of the capacitor C1, and the first end of the capacitor C1 is connected to the first end 5 of the first potentiometer R1. The second end 6 of the first potentiometer R1 is grounded, and the second end 6 of the first potentiometer R1 is the adjustable end. When the second end 6 of the first potentiometer R1 is adjusted, the grounding performance of the capacitor C1 can be adjusted to change the equivalent capacitance value of the capacitor C1, thereby adjusting the reactance impedance (i.e., the imaginary part of the impedance) of the circuit. The third end 7 of the first potentiometer R1 is suspended and can also be connected to other components as needed.

[0042] Figure 4 is a circuit diagram of another impedance adjustment circuit provided in the second embodiment of the present utility model, such as Figure 4 As shown, the reactance element is an inductor L1, which is connected between the first end 5 of the first potentiometer R1 and the third end 10 of the second potentiometer R2, the first end of the inductor L1 is connected to the first end 5 of the first potentiometer R1, and the second end of the inductor L1 is connected to the third end 10 of the second potentiometer R2. Figure 4 The rest of the circuit structure is the same as Figure 3 The circuits shown are exactly the same and will not be described again here.

[0043] Figure 7 1 is a circuit diagram of an impedance adjustment circuit provided in Embodiment 4 of the present utility model. Figure 7 The circuit shown is Figure 3The circuit shown has exactly the same number of circuit elements and connection methods. That is, the reactance element is capacitor C1. Embodiment 4 sets a first adhesive section 1 on the input terminal RF1, and the first adhesive section 1 is glued on the microstrip line of the input terminal RF1. The current flows through the area where the first adhesive section 1 is set at the input terminal RF1 and then flows to the first end 8 of the second potentiometer R2. By adjusting the material, shape and specific position of the first adhesive section 1, the equivalent capacitance and equivalent resistance of the line with the first adhesive section 1 can be changed. Specifically, the first adhesive section 1 forms an additional dielectric layer on the input terminal RF1, and the dielectric layer increases the dielectric constant between the input terminal RF1 and the ground plane. Since the capacitance is proportional to the dielectric constant, the first adhesive section 1 increases the equivalent capacitance value at this location. The presence of the first adhesive section 1 will change the electromagnetic field distribution of the input terminal RF1, thereby affecting the equivalent inductance at this location. That is, the first adhesive section 1 can change the equivalent capacitance value and equivalent inductance of the circuit, thereby affecting the imaginary part of the impedance of the circuit. It should be noted that, in order to ensure the normal operation of the circuit, the first adhesive section 1 is set away from the first end 8 of the second potentiometer R2, and the length of the first adhesive section 1 is less than the total length of the input end RF1. The glue for dispensing can be any glue with a dielectric constant greater than the dielectric constant of air, and the glue can be selected according to actual use to make the first adhesive section 1. When a significant adjustment effect is required, glue with a larger dielectric constant can be used to dispense glue on the microstrip line.

[0044] Figure 8 FIG. 1 is a circuit diagram of another impedance adjustment circuit provided in Embodiment 4 of the present utility model. Figure 8 The circuit shown is Figure 4 The circuit shown has exactly the same number of circuit components and connection methods. Figure 8 The circuit shown also has Figure 7 The first adhesive section 1 in the circuit shown in FIG. 1 has the same setting position and function as the first adhesive section 1. Figure 7 The current flows through the area where the first adhesive section 1 is set at the input terminal RF1 and then flows to the first end 8 of the second potentiometer R2. It should be noted that in order to ensure the normal operation of the circuit, the first adhesive section 1 is set away from the first end 8 of the second potentiometer R2.

[0045] The embodiment of the utility model discloses an impedance adjustment circuit, which includes an input end, a reactance adjustment module and a resistance adjustment module. The reactance adjustment module is provided with a first potentiometer and a reactance element, and the first potentiometer changes the grounding performance of the reactance element to change the reactance resistance of the reactance element, thereby adjusting the imaginary part of the impedance. The resistance adjustment module is provided with a second potentiometer, and the second potentiometer adjusts the resistance impedance of the circuit connected to itself, thereby adjusting the real part of the impedance. The first potentiometer and the second potentiometer are both common potentiometers, and the reactance element adopts a non-adjustable fixed capacitor or a non-adjustable fixed inductor. The non-adjustable fixed capacitor or the non-adjustable fixed inductor has a lower overall cost than the use of an adjustable capacitor or an adjustable inductor. In addition, the adjustable capacitor or the adjustable inductor will bring about a slight change in resistance when adjusted, which will have a certain impact on the capacitance change of the overall equivalent circuit, so that the reliability of the adjustment circuit is reduced. That is, the use of a non-adjustable fixed capacitor or a non-adjustable fixed inductor can improve the reliability of the adjustment circuit. The embodiment of the utility model adopts the above structure and uses relatively simple components to form an adjustment circuit, and adjusts the real part and the imaginary part of the impedance of the circuit, so that the circuit obtains a better impedance adjustment effect.

[0046] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An impedance adjustment circuit, characterized in that: The circuit comprises: Input terminal; The reactance adjustment module comprises a first potentiometer and a reactance element, wherein a first end of the first potentiometer is connected to a first end of the reactance element, and a second end of the first potentiometer is grounded; The resistance adjustment module comprises a second potentiometer, a first end of the second potentiometer is connected to the input end, and a second end of the second potentiometer is grounded.

2. The impedance adjustment circuit according to claim 1, characterized in that: The second end of the reactance element is connected to the input end.

3. The impedance adjustment circuit according to claim 2, characterized in that: The third end of the second potentiometer is suspended.

4. The impedance adjustment circuit according to claim 2, characterized in that: The third end of the second potentiometer is connected to an open line, and the open line has a second adhesive section at the third end away from the second potentiometer, and the length of the second adhesive section is less than or equal to the total length of the open line.

5. The impedance adjustment circuit according to claim 1, characterized in that: The reactance element is connected to the third end of the second potentiometer.

6. The impedance adjustment circuit according to claim 2 or 5, characterized in that: The input end has a first adhesive section.

7. The impedance adjustment circuit according to claim 2 or 5, characterized in that: The third end of the first potentiometer is suspended.

8. The impedance adjustment circuit according to claim 1, characterized in that: The first end of the second potentiometer is an adjustable end.

9. The impedance adjustment circuit according to claim 1, characterized in that: The second end of the first potentiometer is an adjustable end.

10. The impedance adjustment circuit according to claim 1, characterized in that: The reactance element is a capacitor or an inductor.

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