A controllable on-off microstrip coupling circuit

Abstract

The application relates to a controllable on-off microstrip coupling circuit applied to the field of electronic communication technology, which comprises the following steps: introducing a controllable on-resistance element on a microstrip coupling line, controlling the on-resistance element through a voltage source, when the on-resistance element is on, the signal input from an input end is directly transmitted to the ground through the on-resistance element, the off state of the microstrip coupling circuit is realized, when the on-resistance element is off, the signal input from the input end is transmitted through an output end, the on state of the microstrip coupling circuit is realized, the on-off control of the microstrip coupling circuit is realized, compared with the prior art, the on-off control circuit is integrated on the microstrip coupling circuit, the miniaturization design is facilitated, the on-off control circuit structure is simple, and the complexity is low.

Description

Technical Field

[0001] This invention relates to the field of electronic communication technology, and more specifically to a microstrip coupling circuit with controllable switching. Background Technology

[0002] Microstrip coupled circuits are widely used in balanced mixers, amplifiers, filters, frequency multipliers, antennas, etc., mainly for phase shifting, filtering, and matching. Currently, microstrip coupled circuits are uncontrollable. Because they are passive microstrip circuits, traditional methods involve adding switches to the circuit's input and output terminals, or shutting down the power supply in the specific circuit module to achieve no RF signal output. These traditional methods lead to a complex overall RF link, are prone to burning out circuit modules, and have high switching losses and large space requirements, hindering miniaturization design goals. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a controllable on / off microstrip coupling circuit to solve the problems in the prior art, which involve adding a switch design to the circuit input and output terminals, or turning off the power supply in the specific circuit module of the microstrip coupling line application to achieve no RF signal output, resulting in a complex overall RF link, easy burning of the circuit module, and high loss and large space occupation of the switching circuit, which is not conducive to miniaturization design.

[0004] To achieve the above objectives, this application adopts a solution of a controllable on / off microstrip coupling circuit, comprising:

[0005] A first microstrip coupled transmission line, a second microstrip coupled transmission line, an input terminal, and an output terminal;

[0006] The first microstrip coupled transmission line and the second microstrip coupled transmission line are arranged side by side. The input end is located at one end of the first microstrip coupled transmission line, and the output end is located at the end of the second microstrip coupled transmission line away from the input end, forming a centrally symmetrical structure.

[0007] The end of the first microstrip coupled transmission line furthest from the input is connected to one end of a controllable resistor element, and the other end of the controllable resistor element is grounded.

[0008] It also includes: voltage sources;

[0009] The voltage source is used to provide voltage to the controllable resistive element.

[0010] Preferably,

[0011] The controllable resistance element is a FET transistor;

[0012] The drain of the FET transistor is connected to the end of the first microstrip coupled transmission line away from the input terminal, the gate of the FET transistor is connected to a voltage source, and the source of the FET transistor is grounded.

[0013] Preferably,

[0014] It also includes: DC blocking capacitors;

[0015] One end of the DC blocking capacitor is connected to the end of the first microstrip coupled transmission line away from the input end, and the other end of the DC blocking capacitor is connected to the drain of the FET transistor.

[0016] Preferably,

[0017] Also includes: microstrip lines;

[0018] One end of the microstrip line is connected to the other end of the DC blocking capacitor, so that the microstrip line is connected in parallel with the FET transistor, and the other end of the microstrip line is grounded.

[0019] Preferably,

[0020] It also includes: resistors;

[0021] One end of the resistor is connected to a voltage source, and the other end of the resistor is connected to the gate of a FET transistor.

[0022] Preferably,

[0023] The voltage source is a DC controlled voltage source.

[0024] Preferably,

[0025] The lengths of the first and second microstrip coupled transmission lines are one-quarter of the wavelength corresponding to the operating center frequency.

[0026] The widths of the first and second microstrip coupled transmission lines are the linewidths of a microstrip line with a characteristic impedance of 50 ohms.

[0027] Preferably,

[0028] The dielectric substrates of the first and second microstrip coupled transmission lines have a loss tangent of 0.009 and a dielectric constant of 12.9.

[0029] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects:

[0030] This application introduces a controllable resistor element on the microstrip coupling line and controls the conduction of the resistor element through a voltage source. When the resistor element is on, the signal input at the input terminal is directly transmitted to the ground through the conducting element, realizing the off state of the microstrip coupling circuit. When the resistor element is not on, the signal input at the input terminal is transmitted through the output terminal, realizing the on state of the microstrip coupling circuit. This achieves switching control of the microstrip coupling circuit. Compared with the prior art, this application integrates the switching control circuit on the microstrip coupling circuit, which facilitates miniaturization design. Moreover, the switching control circuit of this application has a simple structure and low complexity.

[0031] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0032] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0033] Figure 1 This is a circuit connection diagram of a controllable on / off microstrip coupling circuit according to an exemplary embodiment;

[0034] Figure 2 These are the circuit parameters of a microstrip coupled circuit in the on-state, as shown in another exemplary embodiment.

[0035] Figure 3 These are the circuit parameters of a microstrip coupled circuit in the off state, as shown in another exemplary embodiment.

[0036] In the attached diagram: 1-Input terminal, 2-Output terminal, 3-First microstrip coupled transmission line, 4-Second microstrip coupled transmission line, 5-DC blocking capacitor, 6-Microstrip line, 7-FET transistor, 8-Grounding via, 9-Resistor, 10-Voltage source. Detailed Implementation

[0037] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0038] Example 1

[0039] Figure 1 This is a circuit connection diagram of a controllable on / off microstrip coupled circuit according to an exemplary embodiment, such as... Figure 1 As shown, it includes:

[0040] First microstrip coupled transmission line 3, second microstrip coupled transmission line 4, input terminal 1 and output terminal 2;

[0041] The first microstrip coupled transmission line 3 and the second microstrip coupled transmission line 4 are arranged side by side. The input terminal 1 is located at one end of the first microstrip coupled transmission line 3, and the output terminal 2 is located at the end of the second microstrip coupled transmission line 4 away from the input terminal 1, forming a centrally symmetrical structure.

[0042] The end of the first microstrip coupled transmission line 3 furthest from the input terminal 1 is connected to one end of a controllable resistor element, and the other end of the controllable resistor element is grounded.

[0043] Also includes: voltage source 10;

[0044] The voltage source 10 is used to provide voltage to the controllable resistive element;

[0045] It is understood that this application introduces a controllable resistor element into the microstrip coupling circuit and controls the conduction of the resistor element through the voltage source 10. When the resistor element is on, the signal input at input terminal 1 is directly transmitted to the ground through the grounding hole 8 via the conducting element, realizing the off state of the microstrip coupling circuit. When the resistor element is not on, the signal input at input terminal 1 is transmitted through output terminal 2, realizing the on state of the microstrip coupling circuit. This achieves the switching control of the microstrip coupling circuit. Compared with the prior art, this application integrates the switching control circuit on the microstrip coupling circuit, which is convenient for miniaturization design. Moreover, the switching control circuit of this application has a simple structure and low complexity.

[0046] Preferably,

[0047] The controllable resistance element is a FET transistor 7;

[0048] The drain of the FET transistor 7 is connected to the end of the first microstrip coupled transmission line 3 away from the input terminal 1, the gate of the FET transistor 7 is connected to the voltage source 10, and the source of the FET transistor 7 is grounded.

[0049] It is understood that the conductable resistive element mentioned above in this application can be a variable capacitor or a diode, as well as the FET transistor 7 described in this embodiment. The conduction voltage of the FET transistor 7 is around -1.5V. Therefore, when the voltage of the voltage source 10 is much less than -1.5V, such as -5V, the FET transistor 7 is not conducting. At this time, the input signal at input terminal 1 leaves through output terminal 2, and the microstrip coupling circuit is in the open state. When the voltage of the voltage source 10 is greater than -1.5V, such as 0V, the FET transistor 7 is in the conducting state. The input signal at input terminal 1 enters through the drain of the FET transistor 7, leaves from the source of the FET transistor 7, and is released to ground. At this time, the microstrip coupling circuit is in the off state, realizing the switching control of the microstrip coupling circuit.

[0050] Preferably,

[0051] Also includes: DC blocking capacitor 5;

[0052] One end of the DC blocking capacitor 5 is connected to the end of the first microstrip coupled transmission line 3 away from the input terminal 1, and the other end of the DC blocking capacitor 5 is connected to the drain of the FET transistor 7.

[0053] Understandably, in order to prevent current from other circuits entering from the input terminal 1 from entering through the drain of the FET transistor 7 and causing circuit leakage, a DC blocking capacitor 5 is set between the FET transistor 7 and the input terminal 1. The DC blocking capacitor 5 can effectively isolate DC current and prevent circuit leakage.

[0054] Preferably,

[0055] Also includes: microstrip line 6;

[0056] One end of the microstrip line 6 is connected to the other end of the DC blocking capacitor 5, so that the microstrip line 6 is connected in parallel with the FET transistor 7, and the other end of the microstrip line 6 is grounded.

[0057] Understandably, adding a parallel grounded microstrip line 6 to the drain of FET transistor 7 is equivalent to a grounded inductance, which is used to offset the capacitance of the FET transistor 7 die itself. The beneficial effect is to adjust the impedance of FET transistor 7 in the on state to close to 0 ohms, and to adjust the impedance of FET transistor 7 in the off state to close to infinity, similar to an open circuit.

[0058] Preferably,

[0059] Also includes: resistor 9;

[0060] One end of the resistor 9 is connected to the voltage source 10, and the other end of the resistor 9 is connected to the gate of the FET transistor 7.

[0061] Understandably, the resistance of resistor 9 should be greater than 2000 ohms, which will reduce the conduction loss of FET transistor 7 and protect the die of FET transistor 7 from being broken down by the gate control voltage.

[0062] Preferably,

[0063] The voltage source 10 is a DC controlled voltage source;

[0064] Understandably, DC control voltage sources only have positive and negative wires, resulting in a simple structure, low loss, and low cost.

[0065] Preferably,

[0066] The lengths of the first microstrip coupled transmission line 3 and the second microstrip coupled transmission line 4 are one-quarter of the wavelength corresponding to the working center frequency point.

[0067] The widths of the first microstrip coupled transmission line 3 and the second microstrip coupled transmission line 4 are the linewidths of a microstrip line with a characteristic impedance of 50 ohms.

[0068] It is understandable that the lengths of the first microstrip coupled transmission line 3 and the second microstrip coupled transmission line 4 are approximately equal to a quarter wavelength corresponding to the operating center frequency, and the width is approximately the linewidth of the characteristic impedance of a 50-ohm microstrip line. When the coupled transmission line is constructed according to this structure, the phase of the output signal at the RF output terminal 2 has a 90-degree phase difference relative to the phase of the input signal at the RF input terminal 1, and the transmission loss S21 (dB) will be close to 0, while the return loss S11 (dB) will be below -20dB, achieving a good coupled transmission line effect.

[0069] Preferably,

[0070] The loss tangent of the dielectric substrate of the first microstrip coupled transmission line 3 and the second microstrip coupled transmission line 4 is 0.009, and the dielectric constant is 12.9.

[0071] It is understandable that in order to reduce the line loss of the microstrip coupling line, the loss tangent of the dielectric substrate should be as low as possible. The substrate used in this invention has a loss tangent of 0.009 and a dielectric constant of 12.9.

[0072] It is worth emphasizing that, in this application, the appendix... Figure 2 Appendix Figure 3 These are the on-state and off-state S-parameters for this implementation example. The on-state S-parameters require the control voltage of the DC control voltage source 10 to be set to -5V, causing the FET transistor to be pinched off. The off-state S-parameters require the control voltage of the DC control voltage source 10 to be set to 0V, causing the FET transistor to be turned on. Figure 2This indicates that the controllable microstrip coupling line of this invention, in the on-state, has an S11 coefficient below -12dB, applicable to a frequency band of 20–40GHz, while the transmission loss indicated by the S21 coefficient is within 1.5dB, demonstrating low loss. Figure 3 The controllable microstrip coupling line, in the off-state, has an S11 coefficient within -2dB and an off-state port isolation of -15dB, as indicated by the S21 coefficient. This demonstrates that the circuit structure provided by this patent has good off-state performance and advantages such as miniaturization and easy integration.

[0073] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0074] It should be noted that in the description of this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means at least two.

[0075] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0076] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0077] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0078] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0079] The storage media mentioned above can be read-only memory, disk, or optical disk, etc.

[0080] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0081] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A microstrip coupled circuit with controllable on / off switching, characterized in that, include: A first microstrip coupled transmission line, a second microstrip coupled transmission line, an input terminal, and an output terminal; The first microstrip coupled transmission line and the second microstrip coupled transmission line are arranged side by side. The input end is located at one end of the first microstrip coupled transmission line, and the output end is located at the end of the second microstrip coupled transmission line away from the input end, forming a centrally symmetrical structure. The end of the first microstrip coupled transmission line furthest from the input is connected to one end of a controllable resistor element, and the other end of the controllable resistor element is grounded. The controllable resistance element is a FET transistor; The drain of the FET transistor is connected to the end of the first microstrip coupled transmission line away from the input terminal, the gate of the FET transistor is connected to a voltage source, and the source of the FET transistor is grounded. It also includes: voltage sources; The voltage source is used to provide voltage to the controllable resistive element; It also includes: DC blocking capacitors; One end of the DC blocking capacitor is connected to the end of the first microstrip coupled transmission line away from the input end, and the other end of the DC blocking capacitor is connected to the drain of the FET transistor. Also includes: microstrip lines; One end of the microstrip line is connected to the other end of the DC blocking capacitor, so that the microstrip line is connected in parallel with the FET transistor, and the other end of the microstrip line is grounded.

2. The circuit according to claim 1, characterized in that, It also includes: resistors; One end of the resistor is connected to a voltage source, and the other end of the resistor is connected to the gate of a FET transistor.

3. The circuit according to claim 2, characterized in that, The voltage source is a DC controlled voltage source.

4. The circuit according to claim 3, characterized in that, The lengths of the first and second microstrip coupled transmission lines are one-quarter of the wavelength corresponding to the operating center frequency. The widths of the first and second microstrip coupled transmission lines are the linewidths of a microstrip line with a characteristic impedance of 50 ohms.

5. The circuit according to claim 4, characterized in that, The dielectric substrates of the first and second microstrip coupled transmission lines have a loss tangent of 0.009 and a dielectric constant of 12.9.

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