Double-pole double-throw switch circuit

Abstract

The present invention discloses a double - pole double - throw switch circuit, which includes a first resonant branch, a second resonant branch, a third resonant branch and a fourth resonant branch connected in parallel in sequence. Each resonant branch is connected with a corresponding control port. Both ends of the first resonant branch and both ends of the fourth resonant branch are respectively connected to a third switch branch and a fourth switch branch. Both ends of the second resonant branch and both ends of the third resonant branch are respectively connected to a first switch branch and a second switch branch. The first switch branch is in parallel with the third switch branch, and the second switch branch is in parallel with the fourth switch branch. Each resonant branch includes a first capacitor, a first diode, a first inductor, a second inductor, a second diode and a second capacitor. A control port is connected in parallel between one end of the first capacitor and the positive end of the first diode, between the negative end of the second diode and one end of the second capacitor, and between the first inductor and the second inductor; it has better isolation performance.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave and millimeter-wave switch, and particularly to a double-pole double-throw switch circuit. Background Art

[0002] Due to the advantages of short wavelength, wide bandwidth, all-weather operation, and strong adaptability to smoke in the microwave and millimeter-wave frequency bands, millimeter waves have been widely used in communication, imaging, radar, etc. With the development of millimeter-wave technology, the demand for various millimeter-wave related circuits is also increasing. The millimeter-wave switch circuit is a control circuit and has a very wide application in millimeter-wave systems. The millimeter-wave switch circuit is used to control the conversion of microwave signal channels, and the unidirectional conduction characteristic of the PIN diode makes it the main choice for switch circuit design.

[0003] In the related art, a Ka-band single-pole double-throw PIN switch proposed in the utility model patent with the authorization announcement number CN207625533U includes a radio frequency circuit, a bias circuit, and a drive circuit. The drive circuit is used to provide drive current for the radio frequency circuit and the bias circuit; the radio frequency circuit is an array-type switch circuit, and a single-channel radio frequency circuit includes a multi-PIN tube switch circuit structure formed by several beam lead PIN tubes connected in series; the structure adopted in this solution is a multi-PIN tube structure formed by 4 PIN tubes connected in series at a spacing of 1 / 4 wavelength to achieve single-pole double-throw instead of double-pole double-throw, and the spacing between adjacent beam lead diodes on the microstrip line is λ / 4, where λ is the phase wavelength of the center frequency on the microstrip line, and the flexibility is insufficient; in addition, the single-pole double-throw PIN switch proposed in this solution is a lumped element, and its dimensions are in millimeters or even centimeters, with a large volume.

[0004] In the patent application document with the publication number CN107819174A, an LC resonant single-pole five-throw microwave switch is proposed, which includes a radio frequency module and a drive control circuit. The radio frequency module includes five microwave circuits with the same structure. The five microwave circuits are in parallel and are all connected to the drive control circuit. The microwave circuit includes two PIN diodes and two LC series filter circuits. The PIN diodes are connected in parallel with the LC series filter circuits, and the two PIN diodes are connected in series and have opposite directions; in this solution, the resonant branch adopts LC series resonance to achieve isolation, and only one diode is provided in the switch branch to reduce the insertion loss; in addition, the LC resonant single-pole five-throw microwave switch proposed in this solution is also a lumped element, and its dimensions are in millimeters or even centimeters, with a large volume. Summary of the Invention

[0005] The technical problem to be solved by the present invention is how to provide a double-pole double-throw switch circuit with higher isolation performance.

[0006] The present invention solves the above technical problems by the following technical means:

[0007] The present invention provides a double - pole double - throw switch circuit. The switch circuit includes a first resonant branch, a second resonant branch, a third resonant branch, and a fourth resonant branch connected in parallel in sequence. Each resonant branch is connected with a corresponding control port. Both ends of the first resonant branch and both ends of the fourth resonant branch are respectively connected to a third switch branch and a fourth switch branch. Both ends of the second resonant branch and both ends of the third resonant branch are respectively connected to a first switch branch and a second switch branch. Among them, the first switch branch is in parallel with the third switch branch, and the second switch branch is in parallel with the fourth switch branch;

[0008] The antenna port and the corresponding control port are connected through a first matching branch between the first switch branch and the second switch branch. The common port and the corresponding control port are connected through a second matching branch between the third switch branch and the fourth switch branch. The RF receiving port and the RF transmitting port are respectively connected through a third matching branch and a fourth matching branch between the first switch branch and the second switch branch;

[0009] Among them, each resonant branch includes a first capacitor, a first diode, a first inductor, a second inductor, a second diode, and a second capacitor. One end of the first capacitor is connected to the positive end of the first diode. The negative end of the first diode is connected to the second inductor through the first inductor. The second inductor is connected to the negative end of the second diode. The negative end of the second diode is connected to one end of the second capacitor. And a control port is connected in parallel between one end of the first capacitor and the positive end of the first diode, between the negative end of the second diode and one end of the second capacitor, and between the first inductor and the second inductor.

[0010] Further, both the first switch branch and the second switch branch include a third diode, a fourth diode, a fifth diode, and a sixth diode. The negative end of the third diode is connected to the positive end of the fourth diode. The negative end of the fourth diode is connected to the negative end of the fifth diode. The positive end of the fifth diode is connected to the negative end of the sixth diode. The other end of the first capacitor in the second resonant branch is connected between the third diode and the fourth diode in the first switch branch. The other end of the second capacitor in the second resonant branch is connected between the third diode and the fourth diode in the second switch branch. The other end of the first capacitor in the third resonant branch is connected between the fifth diode and the sixth diode in the first switch branch. The other end of the second capacitor in the third resonant branch is connected between the fifth diode and the sixth diode in the second switch branch;

[0011] The third switch branch and the fourth switch branch each include a seventh diode, an eighth diode, a ninth diode, and a twelfth diode. The positive terminal of the seventh diode is connected to the negative terminal of the eighth diode. The positive terminal of the eighth diode is connected to the positive terminal of the ninth diode. The negative terminal of the ninth diode is connected to the positive terminal of the twelfth diode. The other end of the first capacitor in the first resonant branch is connected between the seventh diode and the eighth diode in the third switch branch. The other end of the second capacitor in the first resonant branch is connected between the seventh diode and the eighth diode in the fourth switch branch. The other end of the first capacitor in the fourth resonant branch is connected between the ninth diode and the twelfth diode in the third switch branch. The other end of the second capacitor in the fourth resonant branch is connected between the ninth diode and the twelfth diode in the fourth switch branch.

[0012] The negative terminal of the seventh diode in the third switch branch is connected to the positive terminal of the third diode in the first switch branch. The negative terminal of the twelfth diode in the third switch branch is connected to the positive terminal of the sixth diode in the first switch branch. The negative terminal of the seventh diode in the fourth switch branch is connected to the positive terminal of the third diode in the second switch branch. The negative terminal of the twelfth diode in the fourth switch branch is connected to the positive terminal of the sixth diode in the second switch branch.

[0013] Further, the first matching branch includes an inductor L7, a capacitor C7, an inductor L8, and a capacitor C8. One end of the inductor L7 is connected to the control port VC_ANT. The other end of the inductor L7 is connected to one end of the capacitor C7. The other end of the capacitor C7 is connected to the antenna port ANT_P. One end of the inductor L8 is connected to the control port VC_ANT. The other end of the inductor L8 is connected to one end of the capacitor C8. The other end of the capacitor C8 is connected to the antenna port ANT_N.

[0014] One end of the capacitor C7 is connected to the negative terminal of the fourth diode in the first switch branch. One end of the capacitor C8 is connected to the negative terminal of the fourth diode in the second switch branch.

[0015] Further, the second matching branch includes an inductor L13, a capacitor C15, an inductor L14, and a capacitor C16. One end of the inductor L13 is connected to the control port VC_COM. The other end of the inductor L13 is connected to one end of the capacitor C15. The other end of the capacitor C15 is connected to the common port COM_P. One end of the inductor L14 is connected to the control port VC_COM. The other end of the inductor L14 is connected to one end of the capacitor C16. The other end of the capacitor C16 is connected to the antenna port COM_N.

[0016] The common port COM_P is connected to the positive terminal of the eighth diode in the third switch branch through the capacitor C15, and the common port COM_N is connected to the positive terminal of the eighth diode in the fourth switch branch through the capacitor C16.

[0017] Further, the third matching branch includes an inductor L3, a capacitor C3, an inductor L4, and a capacitor C4; one end of the inductor L3 is connected to the control port VB_R, the other end of the inductor L3 is connected to one end of the capacitor C3, the other end of the capacitor C3 is connected to the RF receiving port RX_P, one end of the inductor L4 is connected to the control port VB_R, the other end of the inductor L4 is connected to one end of the capacitor C4, and the other end of the capacitor C4 is connected to the RF receiving port RX_N;

[0018] The RF receiving port RX_P is connected to the positive terminal of the third diode in the first switch branch through the capacitor C3, and the RF receiving port RX_N is connected to the positive terminal of the third diode in the second switch branch through the capacitor C4.

[0019] Further, the fourth matching branch includes an inductor L11, a capacitor C11, an inductor L12, and a capacitor C12; one end of the inductor L11 is connected to the control port VB_T, the other end of the inductor L11 is connected to one end of the capacitor C11, the other end of the capacitor C11 is connected to the RF transmitting port TX_P, one end of the inductor L12 is connected to the control port VB_T, the other end of the inductor L12 is connected to one end of the capacitor C12, and the other end of the capacitor C12 is connected to the RF transmitting port TX_N;

[0020] The RF transmitting port TX_P is connected to the positive terminal of the sixth diode in the first switch branch through the capacitor C11, and the RF transmitting port TX_N is connected to the positive terminal of the sixth diode in the second switch branch through the capacitor C12.

[0021] Further, in the first resonant branch, the second resonant branch, the third resonant branch, and the fourth resonant branch, the control port V_R is connected in parallel between one end of the first capacitor and the positive terminal of the first diode through the first resistor, and the control port V_R is connected in parallel between the negative terminal of the second diode and one end of the second capacitor through the second resistor.

[0022] Further, a control port VC_T is connected in parallel between the first inductor and the second inductor in the first resonant branch, a control port VC_R is connected in parallel between the first inductor and the second inductor in the second resonant branch, a control port VC_T is connected in parallel between the first inductor and the second inductor in the third resonant branch, and a control port VC_R is connected in parallel between the first inductor and the second inductor in the fourth resonant branch.

[0023] Further, the capacitors and inductors in each resonant branch resonate within the operating frequency band.

[0024] Furthermore, the values of the first inductor and the second inductor in each resonant branch are 80.5 pH, and the values of the first capacitor and the second capacitor are 56 fF.

[0025] The advantages of the present invention are as follows:

[0026] (1) By applying a high level / low level to the control port, the present invention controls the connection between the antenna port and the RF receiving port or the RF transmitting port, and the connection between the RF transmitting port and the common port or the antenna port. Through the corresponding matching circuit, each switch branch is matched with the common port, the antenna port, the RF receiving port, and the RF transmitting port. At this time, the inductors and capacitors in the four resonant branches resonate within the operating frequency band, optimizing the port matching and improving the isolation between the antenna port and the common port, as well as between the RF transmitting port and the RF receiving port.

[0027] (2) All four switch branches utilize the unidirectional conduction principle of the diode PIN, having lower switch insertion loss.

[0028] (3) The present invention is particularly applicable to the millimeter-wave (30 G - 300 GHz) frequency band. All components are on-chip devices, having the advantages of small area and high integration, which can greatly save costs.

[0029] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. Description of the Drawings

[0030] Figure 1 is a schematic structural diagram of a double-pole double-throw switch circuit proposed in an embodiment of the present invention;

[0031] Figure 2 is a diagram of the port conduction relationship in the receiving state in an embodiment of the present invention;

[0032] Figure 3 is a diagram of the reflection coefficient, insertion loss, and isolation between port 1 and port 2 and between port 3 and port 4 in the receiving state in an embodiment of the present invention;

[0033] Figure 4 is a diagram of the port conduction relationship in the transmitting state in an embodiment of the present invention;

[0034] Figure 5 is a diagram of the reflection coefficient, insertion loss, and isolation between port 1 and port 2 and between port 3 and port 4 in the transmitting state in an embodiment of the present invention. Detailed Embodiment

[0035] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Apparently, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0036] As Figure 1 shown, an embodiment of the present invention provides a double-pole double-throw switch circuit. The switch circuit includes a first resonant branch, a second resonant branch, a third resonant branch, and a fourth resonant branch connected in parallel in sequence. Each resonant branch is connected to a corresponding control port. Both ends of the first resonant branch and both ends of the fourth resonant branch are respectively connected to a third switch branch and a fourth switch branch. Both ends of the second resonant branch and both ends of the third resonant branch are respectively connected to a first switch branch and a second switch branch. Among them, the first switch branch is in parallel with the third switch branch, and the second switch branch is in parallel with the fourth switch branch;

[0037] The antenna port and the corresponding control port are connected to the first switch branch and the second switch branch through a first matching branch. The common port and the corresponding control port are connected to the third switch branch and the fourth switch branch through a second matching branch. The RF receiving port and the RF transmitting port are respectively connected to the first switch branch and the second switch branch through a third matching branch and a fourth matching branch;

[0038] Among them, each resonant branch includes a first capacitor, a first diode, a first inductor, a second inductor, a second diode, and a second capacitor. One end of the first capacitor is connected to the positive terminal of the first diode. The negative terminal of the first diode is connected to the second inductor through the first inductor. The second inductor is connected to the negative terminal of the second diode. The negative terminal of the second diode is connected to one end of the second capacitor. A control port is connected in parallel between one end of the first capacitor and the positive terminal of the first diode, between the negative terminal of the second diode and one end of the second capacitor, and between the first inductor and the second inductor.

[0039] Specifically, the specific circuit relationships of each resonant branch are described as follows: The first resonant branch includes a first capacitor, i.e., capacitor C1, a first diode, i.e., diode D17, a first inductor, i.e., inductor L1, a second inductor, i.e., inductor L2, a second diode, i.e., diode D18, and a second capacitor, i.e., capacitor C2. One end of capacitor C1 is connected to the positive terminal of diode D9, the other end of capacitor C1 is connected to the positive terminal of diode D17, the negative terminal of diode D17 is connected to one end of inductor L1, the other end of inductor L1 is connected to one end of inductor L2, the other end of inductor L2 is connected to the negative terminal of diode D18, the positive terminal of diode D18 is connected to one end of capacitor C2, the other end of capacitor C2 is connected to the positive terminal of diode D13, and the control port VC_T is connected in parallel between inductor L1 and inductor L2.

[0040] The second resonant branch includes a first capacitor, i.e., capacitor C5, a first diode, i.e., diode D19, a first inductor, i.e., inductor L5, a second inductor, i.e., inductor L6, a second diode, i.e., diode D20, and a second capacitor, i.e., capacitor C6. One end of capacitor C5 is connected to the positive terminal of diode D2, the other end of capacitor C5 is connected to the positive terminal of diode D19, the negative terminal of diode D19 is connected to inductor L5, the other end of inductor L5 is connected to inductor L6, the other end of inductor L6 is connected to the negative terminal of diode D20, the positive terminal of diode D20 is connected to capacitor C6, the other end of capacitor C6 is connected to the positive terminal of diode D6, and the control port VC_R is connected in parallel between inductor L5 and inductor L6.

[0041] The third resonant branch includes a first capacitor, i.e., capacitor C9, a first diode, i.e., diode D21, a first inductor, i.e., inductor L9, a second inductor, i.e., inductor L10, a second diode, i.e., diode D22, and a second capacitor, i.e., capacitor C10. One end of capacitor C9 is connected to the positive terminal of diode D3, the other end of capacitor C9 is connected to the positive terminal of diode D21, the negative terminal of diode D21 is connected to inductor L9, the other end of inductor L9 is connected to inductor L10, the other end of inductor L10 is connected to the negative terminal of diode D22, the positive terminal of diode D22 is connected to capacitor C10, the other end of capacitor C10 is connected to the positive terminal of diode D7, and the control port VC_T is connected in parallel between inductor L9 and inductor L10.

[0042] The fourth resonant branch includes a first capacitor, i.e., capacitor C13, a first diode, i.e., diode D23, a first inductor, i.e., inductor L15, a second inductor, i.e., inductor L16, a second diode, i.e., diode D24, and a second capacitor, i.e., capacitor C14. One end of capacitor C13 is connected to the positive terminal of diode D12, the other end of capacitor C13 is connected to the positive terminal of diode D23, the negative terminal of diode D23 is connected to inductor L15, the other end of inductor L15 is connected to inductor L16, the other end of inductor L16 is connected to the negative terminal of diode D24, the positive terminal of diode D24 is connected to capacitor C14, the other end of capacitor C14 is connected to the positive terminal of diode D16, and the control port VC_R is connected in parallel between inductor L15 and inductor L16.

[0043] In the resonant branch designed in this embodiment, a diode is connected in series between the series-connected inductor L and capacitor C. By controlling the on / off of the diode, the isolation between ports can be increased. For example, when antenna port 1 and RF receiving port 3 are connected, and common port 2 and RF transmitting port 4 are connected, by controlling the on / off of the series-connected diode in the resonant branch, the first and third resonant branches are turned on, and the second and fourth resonant branches are turned off, which can greatly improve the isolation between port 1 and port 4, and between port 2 and port 3.

[0044] In addition, all devices in the circuit structure of the resonant branch designed in this embodiment use on-chip components. The resonant branch uses on-chip inductor L, on-chip capacitor C, and on-chip diode, with small area and high integration. Especially in the millimeter-wave (30G - 300GHz) frequency band, such as in the 70G - 80GHz frequency band, the typical size of on-chip inductor L is about 100um * 100um, and the typical size of on-chip capacitor is about 50um * 50um. Compared with off-chip inductor and off-chip capacitor, it greatly saves the area cost and has a high integration.

[0045] As a further preferred technical solution, both the first switch branch and the second switch branch include a third diode, a fourth diode, a fifth diode, and a sixth diode. The negative terminal of the third diode is connected to the positive terminal of the fourth diode, the negative terminal of the fourth diode is connected to the negative terminal of the fifth diode, the positive terminal of the fifth diode is connected to the negative terminal of the sixth diode. The other end of the first capacitor in the second resonant branch is connected between the third diode and the fourth diode in the first switch branch, the other end of the second capacitor in the second resonant branch is connected between the third diode and the fourth diode in the second switch branch, the other end of the first capacitor in the third resonant branch is connected between the fifth diode and the sixth diode in the first switch branch, and the other end of the second capacitor in the third resonant branch is connected between the fifth diode and the sixth diode in the second switch branch;

[0046] The third switch branch and the fourth switch branch each include a seventh diode, an eighth diode, a ninth diode, and a twelfth diode. The positive terminal of the seventh diode is connected to the negative terminal of the eighth diode, the positive terminal of the eighth diode is connected to the positive terminal of the ninth diode, and the negative terminal of the ninth diode is connected to the positive terminal of the twelfth diode. The other end of the first capacitor in the first resonant branch is connected between the seventh diode and the eighth diode in the third switch branch, and the other end of the second capacitor in the first resonant branch is connected between the seventh diode and the eighth diode in the fourth switch branch. The other end of the first capacitor in the fourth resonant branch is connected between the ninth diode and the twelfth diode in the third switch branch, and the other end of the second capacitor in the fourth resonant branch is connected between the ninth diode and the twelfth diode in the fourth switch branch.

[0047] The negative terminal of the seventh diode in the third switch branch is connected to the positive terminal of the third diode in the first switch branch, and the negative terminal of the twelfth diode in the third switch branch is connected to the positive terminal of the sixth diode in the first switch branch. The negative terminal of the seventh diode in the fourth switch branch is connected to the positive terminal of the third diode in the second switch branch, and the negative terminal of the twelfth diode in the fourth switch branch is connected to the positive terminal of the sixth diode in the second switch branch.

[0048] The switch branch designed in this embodiment adopts a structure in which two pairs of diodes are connected in series in opposite directions, which can realize the double-pole double-throw function, has a flexible structure, and has no requirement for the distance between the diodes, with stronger flexibility. The method of connecting two diodes in series is adopted, and the resonant branch is led out at the connection between the two diodes, increasing the isolation degree. For example, in the first switch branch unit, the two pairs of diodes are diode D1, diode D2 and diode D3, diode D4 respectively, where diode D1 and diode D2 are connected in series, diode D3 and diode D4 are connected in series, and diode D1, diode D2 and diode D3, diode D4 are in opposite directions.

[0049] Moreover, the diodes used in the switch branch of this embodiment are all on-chip diodes, with very small sizes, only in the order of a few hundred micrometers, high integration, and low cost can be achieved. Especially in the millimeter wave (30G - 300GHz) band, such as in the 70G - 80GHz band, the typical size of the on-chip diode is about 15um * 15um. Compared with off-chip diodes (board-level circuits), the area cost is greatly saved and the integration is very high. Due to the use of on-chip components with low loss and resonant branches in the switch branch structure, extremely low insertion loss and high isolation degree can be achieved.

[0050] Specifically, as Figure 1 shown, the specific circuit relationships of each switch branch are described as follows:

[0051] The first switching branch includes a third diode, i.e., diode D1, a fourth diode, i.e., diode D2, a fifth diode, i.e., diode D3, and a sixth diode, i.e., diode D4. Among them, the positive terminal of diode D1 is connected in parallel between inductor L3 and capacitor C3, the negative terminal of diode D1 is connected to the positive terminal of diode D2, the negative terminal of diode D2 is connected to the negative terminal of diode D3, the positive terminal of diode D3 is connected to the negative terminal of diode D4, and the positive terminal of diode D4 is connected in parallel between inductor L11 and capacitor C11.

[0052] The second switching branch includes a third diode, i.e., diode D5, a fourth diode, i.e., diode D6, a fifth diode, i.e., diode D7, and a sixth diode, i.e., diode D8. Among them, the positive terminal of diode D5 is connected in parallel between inductor L4 and capacitor C4, the negative terminal of diode D5 is connected to the positive terminal of diode D6, the negative terminal of diode D6 is connected to the negative terminal of diode D7, the positive terminal of diode D7 is connected to the negative terminal of diode D8, and the positive terminal of diode D8 is connected in parallel between inductor L12 and capacitor C12.

[0053] The third switching branch includes a seventh diode, i.e., diode D9, an eighth diode, i.e., diode D10, a ninth diode, i.e., diode D11, and a twelfth diode, i.e., diode D12. Among them, the negative terminal of diode D9 is connected to the positive terminal of diode D1, the positive terminal of diode D9 is connected to the negative terminal of diode D10, the positive terminal of diode D10 is connected to the positive terminal of diode D11, the negative terminal of diode D11 is connected to the positive terminal of diode D12, and the negative terminal of diode D12 is connected to the positive terminal of diode D4.

[0054] The fourth switching branch includes a seventh diode, i.e., diode D13, an eighth diode, i.e., diode D14, a ninth diode, i.e., diode D15, and a twelfth diode, i.e., diode D16. Among them, the negative terminal of diode D13 is connected to the positive terminal of diode D5, the positive terminal of diode D13 is connected to the negative terminal of diode D14, the positive terminal of diode D14 is connected to the positive terminal of diode D15, the negative terminal of diode D15 is connected to the positive terminal of diode D16, and the negative terminal of diode D16 is connected to the positive terminal of diode D8.

[0055] As a further preferred technical solution, as Figure 1 shown, the first matching branch includes inductor L7, capacitor C7, inductor L8, and capacitor C8. One end of inductor L7 is connected to the control port VC_ANT, the other end of inductor L7 is connected to one end of capacitor C7, the other end of capacitor C7 is connected to the antenna port ANT_P, one end of inductor L8 is connected to the control port VC_ANT, the other end of inductor L8 is connected to one end of capacitor C8, and the other end of capacitor C8 is connected to the antenna port ANT_N.

[0056] One end of the capacitor C7 is connected to the negative terminal of the fourth diode in the first switching branch, and one end of the capacitor C8 is connected to the negative terminal of the fourth diode in the second switching branch.

[0057] The second matching branch includes an inductor L13, a capacitor C15, an inductor L14, and a capacitor C16; one end of the inductor L13 is connected to the control port VC_COM, the other end of the inductor L13 is connected to one end of the capacitor C15, the other end of the capacitor C15 is connected to the common port COM_P, one end of the inductor L14 is connected to the control port VC_COM, the other end of the inductor L14 is connected to one end of the capacitor C16, and the other end of the capacitor C16 is connected to the antenna port COM_N;

[0058] The common port COM_P is connected to the positive terminal of the eighth diode in the third switching branch through the capacitor C15, and the common port COM_N is connected to the positive terminal of the eighth diode in the fourth switching branch through the capacitor C16.

[0059] The third matching branch includes an inductor L3, a capacitor C3, an inductor L4, and a capacitor C4; one end of the inductor L3 is connected to the control port VB_R, the other end of the inductor L3 is connected to one end of the capacitor C3, the other end of the capacitor C3 is connected to the RF receiving port RX_P, one end of the inductor L4 is connected to the control port VB_R, the other end of the inductor L4 is connected to one end of the capacitor C4, and the other end of the capacitor C4 is connected to the RF receiving port RX_N;

[0060] The RF receiving port RX_P is connected to the positive terminal of the third diode in the first switching branch through the capacitor C3, and the RF receiving port RX_N is connected to the positive terminal of the third diode in the second switching branch through the capacitor C4.

[0061] The fourth matching branch includes an inductor L11, a capacitor C11, an inductor L12, and a capacitor C12; one end of the inductor L11 is connected to the control port VB_T, the other end of the inductor L11 is connected to one end of the capacitor C11, the other end of the capacitor C11 is connected to the RF transmitting port TX_P, one end of the inductor L12 is connected to the control port VB_T, the other end of the inductor L12 is connected to one end of the capacitor C12, and the other end of the capacitor C12 is connected to the RF transmitting port TX_N;

[0062] The RF transmitting port TX_P is connected to the positive terminal of the sixth diode in the first switching branch through the capacitor C11, and the RF transmitting port TX_N is connected to the positive terminal of the sixth diode in the second switching branch through the capacitor C12.

[0063] It should be noted that the inductors, capacitors, etc. used in each matching branch of this embodiment are all on-chip inductors and on-chip capacitors, which have a small area and a high integration degree.

[0064] As a further preferred technical solution, there are antenna ports ANT_P, ANY_N, common ports COM_P, COM_N, radio frequency receiving ports RX_P, RX_N, radio frequency transmitting ports TX_P, TX_N, and control ports VB_R, VB_T, V_R, VC_R, VC_ANT, VC_T, VC_COM. Among them:

[0065] In the first resonant branch, the second resonant branch, the third resonant branch, and the fourth resonant branch, the control port V_R is connected in parallel between one end of the first capacitor and the positive terminal of the first diode through the first resistor, and the control port V_R is connected in parallel between the negative terminal of the second diode and one end of the second capacitor through the second resistor. That is, the control port V_R is respectively connected to the positive terminals of the diodes D17, D18, D19, D20, D21, D22, D23, D24 connected in parallel through the resistors R1, R2, R3, R4, R5, R6, R7, R8, and is connected to the first, second, third, and fourth resonant branches.

[0066] The radio frequency receiving ports RX_P, RX_N are respectively connected to the positive terminal of the diode D1 in the first switching branch and the positive terminal of the diode D5 in the second switching branch through the capacitors C3, C4; the antenna ports ANT_P, ANY_N are respectively connected to the negative terminal of the diode D2 in the first switching branch and the negative terminal of the diode D6 in the second switching branch through the capacitors C7, C8; the radio frequency transmitting ports TX_P, TX_N are respectively connected to the positive terminal of the diode D4 in the first switching branch and the positive terminal of the diode D8 in the second switching branch through the capacitors C11, C12; the common ports COM_P, COM_N are respectively connected to the positive terminal of the diode D10 in the third switching branch and the positive terminal of the diode D14 in the fourth switching branch through the capacitors C15, C16.

[0067] As a further preferred technical solution, the capacitors and inductors in each resonant branch resonate within the working frequency band. Specifically: the inductor L1 and the capacitor C1, the inductor L2 and the capacitor C2, the inductor L5 and the capacitor C5, the inductor L6 and the capacitor C6, the inductor L9 and the capacitor C9, the inductor L10 and the capacitor C10, the inductor L15 and the capacitor C13, the inductor L16 and the capacitor C14, all resonate at the designed frequency point w0, that is L represents the inductance value of the resonant branch, and C represents the capacitance value of the resonant branch, which improves the port matching and the port isolation.

[0068] Next, the working principle of a double-pole double-throw switch circuit proposed by the present invention when the working frequency band is from 70 GHz to 80 GHz will be described:

[0069] (1) When the control ports V_R, VC_COM, VB_R, VC_R are at the high level of 3.3V and the control ports VB_T, VC_ANT, VC_T are at the low level of 0V, the diodes D1, D2, D5, D6 conduct, and the antenna port is connected to the RF receiving port; the diodes D11, D12, D15, D16 conduct, and the RF transmitting port is connected to the common port; the diodes D17, D18, D21, D22 conduct, and the first and third resonant branches conduct; the diodes D19, D20, D23, D24 do not conduct, and the second and fourth resonant branches do not conduct. This state is the receiving state, where the antenna port is connected to the RF receiving port and the RF transmitting port is connected to the common port. The port conduction relationship diagram in the receiving state is as shown in Figure 2 shown.

[0070] Among them, the inductors L3, C3, L4, C4 are for matching the circuit with the RF input port; the inductors L11, C11, L12, C12 are for matching the circuit with the RF transmitting port; the inductors L7, C7, L8, C8 are for matching the circuit with the antenna port; the inductors L13, C15, L14, C16 are for matching the circuit with the common port. At the same time, the inductors L3, L4, L11, L12, L13, L14 have the function of blocking alternating current, and the capacitors C3, C4, C11, C12, C15, C16 have the function of blocking direct current; the inductors and capacitors in the first and third resonant branches resonate within the working frequency band, optimizing the port matching and improving the isolation between the antenna port and the common port as well as between the RF transmitting port and the RF receiving port. The reflection coefficient, insertion loss, and isolation between port 1 and port 2 and between port 3 and port 4 of each port in the receiving state are as shown in Figure 3 shown, where port 1 represents the antenna port, port 2 represents the common port, port 3 represents the RF receiving port, and port 4 represents the RF transmitting port. Figure 3 The ports of Figure 2 can refer to Figure 5 and the ports in Figure 4 can be seen in

[0071] In this example, the values of the inductors and capacitors in the first, second, third, and fourth resonant branches are 80.5 pH and 56 fF respectively. In this receiving state, the reflection coefficients of the four ports within the working frequency band are all less than -10 dB, reaching -40 dB in the best case, the isolation between ports is less than -41 dB, and the insertion loss is less than 1.5 dB.

[0072] (2) When V_R, VC_COM, VB_T, and VC_T are at the high level of 3.3V, and VB_R, VC_ANT, and VC_R are at the low level of 0V, diodes D9, D10, D13, and D14 conduct, and the common port is connected to the RF receiving port; diodes D3, D4, D7, and D8 conduct, and the RF transmitting port is connected to the antenna port; diodes D17, D18, D21, and D22 do not conduct, and the first and third resonant branches do not conduct; diodes D19, D20, D23, and D24 conduct, and the second and fourth resonant branches conduct. At this time, it is in the transmitting state, the antenna port is connected to the RF transmitting port, and the RF receiving port is connected to the common port. The port conduction relationship diagram in the transmitting state is as shown in Figure 4 shown.

[0073] Among them, inductors L3 and C3, inductors L4 and C4 are used to match the circuit with the RF input port; inductors L11 and C11, inductors L12 and C12 are used to match the circuit with the RF transmitting port; inductors L7 and C7, inductors L8 and C8 are used to match the circuit with the antenna port; inductors L13 and C15, inductors L14 and C16 are used to match the circuit with the common port. At the same time, inductors L3, L4, L11, L12, L13, and L14 have the function of blocking alternating current, and capacitors C3, C4, C11, C12, C15, and C16 have the function of blocking direct current; the inductors and capacitors in the second and fourth resonant branches resonate within the working frequency band, optimizing the port matching and improving the isolation between the antenna port and the common port and between the RF transmitting port and the RF receiving port. The reflection coefficient, insertion loss, and isolation between port 1 and port 2 and between port 3 and port 4 of each port in the transmitting state are as shown in Figure 5 shown, Figure 5 where port 1 represents the antenna port, port 2 represents the common port, port 3 represents the RF receiving port, and port 4 represents the RF transmitting port.

[0074] In this transmitting state, the reflection coefficients of the four ports within the working frequency band are all less than -10dB, reaching -40dB in the best case, the isolation between the ports is less than -41dB, and the insertion loss is better than 1.5dB.

[0075] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0076] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0077] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A double-pole double-throw switch circuit, characterized in that, The switching circuit includes a first resonant branch, a second resonant branch, a third resonant branch, and a fourth resonant branch connected in parallel in sequence. Each resonant branch is connected to a corresponding control port. Both ends of the first resonant branch and both ends of the fourth resonant branch are respectively connected to a third switching branch and a fourth switching branch. Both ends of the second resonant branch and both ends of the third resonant branch are respectively connected to a first switching branch and a second switching branch. Among them, the first switching branch is connected in parallel with the third switching branch, and the second switching branch is connected in parallel with the fourth switching branch; The antenna port and the corresponding control port are connected through a first matching branch between the first switching branch and the second switching branch. The common port and the corresponding control port are connected through a second matching branch between the third switching branch and the fourth switching branch. The RF receiving port and the RF transmitting port are respectively connected through a third matching branch and a fourth matching branch between the first switching branch and the second switching branch; Among them, each resonant branch includes a first capacitor, a first diode, a first inductor, a second inductor, a second diode, and a second capacitor. One end of the first capacitor is connected to the positive terminal of the first diode. The negative terminal of the first diode is connected to the second inductor through the first inductor. The second inductor is connected to the negative terminal of the second diode. The negative terminal of the second diode is connected to one end of the second capacitor. And a control port is connected in parallel between one end of the first capacitor and the positive terminal of the first diode, between the negative terminal of the second diode and one end of the second capacitor, and between the first inductor and the second inductor; The first switching branch and the second switching branch both include a third diode, a fourth diode, a fifth diode, and a sixth diode. The negative terminal of the third diode is connected to the positive terminal of the fourth diode. The negative terminal of the fourth diode is connected to the negative terminal of the fifth diode. The positive terminal of the fifth diode is connected to the negative terminal of the sixth diode. The other end of the first capacitor in the second resonant branch is connected between the third diode and the fourth diode in the first switching branch. The other end of the second capacitor in the second resonant branch is connected between the third diode and the fourth diode in the second switching branch. The other end of the first capacitor in the third resonant branch is connected between the fifth diode and the sixth diode in the first switching branch. The other end of the second capacitor in the third resonant branch is connected between the fifth diode and the sixth diode in the second switching branch; The third switching branch and the fourth switching branch each include a seventh diode, an eighth diode, a ninth diode, and a twelfth diode. The positive terminal of the seventh diode is connected to the negative terminal of the eighth diode, the positive terminal of the eighth diode is connected to the positive terminal of the ninth diode, and the negative terminal of the ninth diode is connected to the positive terminal of the twelfth diode. The other end of the first capacitor in the first resonant branch is connected between the seventh diode and the eighth diode in the third switching branch, and the other end of the second capacitor in the first resonant branch is connected between the seventh diode and the eighth diode in the fourth switching branch. The other end of the first capacitor in the fourth resonant branch is connected between the ninth diode and the twelfth diode in the third switching branch, and the other end of the second capacitor in the fourth resonant branch is connected between the ninth diode and the twelfth diode in the fourth switching branch. The negative terminal of the seventh diode in the third switching branch is connected to the positive terminal of the third diode in the first switching branch, and the negative terminal of the twelfth diode in the third switching branch is connected to the positive terminal of the sixth diode in the first switching branch. The negative terminal of the seventh diode in the fourth switching branch is connected to the positive terminal of the third diode in the second switching branch, and the negative terminal of the twelfth diode in the fourth switching branch is connected to the positive terminal of the sixth diode in the second switching branch.

2. The double-pole double-throw switch circuit according to claim 1, wherein The first matching branch includes an inductor L7, a capacitor C7, an inductor L8, and a capacitor C8. One end of the inductor L7 is connected to the control port VC_ANT, the other end of the inductor L7 is connected to one end of the capacitor C7, the other end of the capacitor C7 is connected to the antenna port ANT_P, one end of the inductor L8 is connected to the control port VC_ANT, the other end of the inductor L8 is connected to one end of the capacitor C8, and the other end of the capacitor C8 is connected to the antenna port ANT_N. One end of the capacitor C7 is connected to the negative terminal of the fourth diode in the first switching branch, and one end of the capacitor C8 is connected to the negative terminal of the fourth diode in the second switching branch.

3. The double-pole double-throw switch circuit according to claim 1, wherein The second matching branch includes an inductor L13, a capacitor C15, an inductor L14, and a capacitor C16. One end of the inductor L13 is connected to the control port VC_COM, the other end of the inductor L13 is connected to one end of the capacitor C15, the other end of the capacitor C15 is connected to the common port COM_P, one end of the inductor L14 is connected to the control port VC_COM, the other end of the inductor L14 is connected to one end of the capacitor C16, and the other end of the capacitor C16 is connected to the antenna port COM_N. The common port COM_P is connected to the positive terminal of the eighth diode in the third switching branch through the capacitor C15, and the common port COM_N is connected to the positive terminal of the eighth diode in the fourth switching branch through the capacitor C16.

4. The double-pole double-throw switch circuit according to claim 1, wherein The third matching branch includes an inductor L3, a capacitor C3, an inductor L4, and a capacitor C4; one end of the inductor L3 is connected to the control port VB_R, the other end of the inductor L3 is connected to one end of the capacitor C3, the other end of the capacitor C3 is connected to the RF receiving port RX_P, one end of the inductor L4 is connected to the control port VB_R, the other end of the inductor L4 is connected to one end of the capacitor C4, and the other end of the capacitor C4 is connected to the RF receiving port RX_N; The RF receiving port RX_P is connected to the positive terminal of the third diode in the first switching branch through the capacitor C3, and the RF receiving port RX_N is connected to the positive terminal of the third diode in the second switching branch through the capacitor C4.

5. The double-pole double-throw switch circuit according to claim 1, characterized in that The fourth matching branch includes an inductor L11, a capacitor C11, an inductor L12, and a capacitor C12; one end of the inductor L11 is connected to the control port VB_T, the other end of the inductor L11 is connected to one end of the capacitor C11, the other end of the capacitor C11 is connected to the RF transmitting port TX_P, one end of the inductor L12 is connected to the control port VB_T, the other end of the inductor L12 is connected to one end of the capacitor C12, and the other end of the capacitor C12 is connected to the RF transmitting port TX_N; The RF transmitting port TX_P is connected to the positive terminal of the sixth diode in the first switching branch through the capacitor C11, and the RF transmitting port TX_N is connected to the positive terminal of the sixth diode in the second switching branch through the capacitor C12.

6. The double-pole double-throw switch circuit according to claim 1, characterized in that, In the first resonant branch, the second resonant branch, the third resonant branch, and the fourth resonant branch, the control port V_R is connected in parallel between one end of the first capacitor and the positive terminal of the first diode through the first resistor, and the control port V_R is connected in parallel between the negative terminal of the second diode and one end of the second capacitor through the second resistor.

7. The double-pole double-throw switch circuit according to claim 1, wherein A control port VC_T is connected in parallel between the first inductor and the second inductor in the first resonant branch, a control port VC_R is connected in parallel between the first inductor and the second inductor in the second resonant branch, a control port VC_T is connected in parallel between the first inductor and the second inductor in the third resonant branch, and a control port VC_R is connected in parallel between the first inductor and the second inductor in the fourth resonant branch.

8. The double-pole double-throw switch circuit according to any one of claims 1 to 7, characterized in that, The capacitors and inductors in each resonant branch resonate within the operating frequency band.

9. The double-pole double-throw switch circuit according to any one of claims 1 to 7, characterized in that, The values of the first inductor and the second inductor in each resonant branch are 80.5 pH, and the values of the first capacitor and the second capacitor are 56 fF.

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