Circuit for improving port isolation of radio frequency switch built by PIN tubes
By adding PIN diodes D4, D5, D6 to the RF switch circuit and adjusting the voltage relationship, the problem of insufficient isolation of RF switch ports in the prior art is solved, and a higher port isolation effect is achieved.
Patent Information
- Application Number
- CN202421494444.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-27
- Publication Date
- 2025-05-09
- Estimated Expiration
- 2034-06-27
AI Technical Summary
In the prior art, the port isolation of the RF switch built with PIN tubes is insufficient in the disconnected state, which affects the isolation effect of the RF link.
Add three PIN diodes D4, D5, and D6 to the circuit, and adjust the voltage relationship between the power supply terminals vbb, vcc and ground terminal GND to vcc < GND < vbb to ensure that when Term1 and Term2 are turned on, the Term3 and Term4 ports are in a disconnected state, and the radio frequency link connected to Term3 and Term4 ports are short-circuited to ground through D5 and D6.
It significantly improves the isolation of Term3 and Term4 ports, reduces its impact on other port products, and achieves a higher port isolation effect.
Smart Images
Figure CN222852263U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a circuit for improving the port isolation of a radio frequency switch constructed by using a PIN tube, and belongs to the technical field of radio frequency switches. Background Art
[0002] Figure 1 This is a 1:3 RF switch implemented with a PIN diode. The RF switch built with a PIN diode is realized by making the PIN diode in the circuit in the on and off working states. Figure 1 When RFC-RF1 is turned on, RF2 and RF3 are in a disconnected state. At this time, the higher the isolation between RF2, RF3 and other ports, the better. The circuit of this solution can improve the isolation between the port in the disconnected state and other ports.
[0003] The RF switch and peripheral circuit built with PIN diodes are shown in Figure 2 As shown in the figure, the circuit is simulated by ADS at an operating frequency of 100-500MHz, Term2 is in the on state, and Term3 and Term4 are in the off state. Figure 3 From the simulation results, we can see that the isolation of Term3 and Term4 ports at 500MHz is S(3, 1) = -25.7dB, S(3, 2) = -25.7dB, S(4, 1) = -25.7dB, S(4, 2) = -25.7dB, and S(4, 3) = -51.4dB. Summary of the invention
[0004] The technical problem to be solved by the utility model is to provide a circuit for improving the port isolation of a radio frequency switch constructed by a PIN tube, so as to solve the problems existing in the above-mentioned prior art.
[0005] The technical solution adopted by the utility model is: a circuit for improving the port isolation of a radio frequency switch built with a PIN tube, comprising an inductor L1, an inductor L2, an inductor L3, an inductor L4, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a diode D1, a diode D2, a diode D3, a diode D4, a diode D5, a diode D6, a resistor R1, a resistor R2 and a resistor R3, one end of the capacitor C1 is connected to the Trem1 port, and the other end is connected to one end of the inductor L1 and the positive electrodes of the diodes D1, D2 and D3, the negative electrodes of the diodes D1, D2 and D3 are respectively connected to one end of the capacitors C2, C3 and C4, and the other ends of the capacitors C2, C3 and C4 are respectively connected to the Trem2 port and the Trem3 port. m3 port and Trem4 port, one end of the connection between the diode D1 and the capacitor C2 is connected to one end of the inductor L2 and the positive electrode of the diode D4, one end of the connection between the diode D2 and the capacitor C3 is connected to one end of the inductor L3 and the positive electrode of the diode D5, one end of the connection between the diode D3 and the capacitor C4 is connected to one end of the inductor L4 and the positive electrode of the diode D6, the other ends of the inductor L2, the inductor L3 and the inductor L4 are respectively connected to one end of the resistor R1, the resistor R2 and the resistor R3, the other ends of the resistor R1, the resistor R2 and the resistor R3 are connected to the power supply terminal vcc and the two power supply terminals vbb, the other end of the inductor L1 is connected to the ground terminal GND, and the cathodes of the diodes D4, the diodes D5 and the diode D6 are connected to the ground terminal GND.
[0006] Furthermore, the voltage relationship among the power supply terminal vbb, the power supply terminal vcc and the ground terminal GND is vcc<GND<vbb.
[0007] Beneficial effects of the utility model: Compared with the prior art, the utility model adds three PIN diodes D4, D5, and D6, and the voltage relationship between vbb, vcc and GND is vcc<GND<vbb. Therefore, when Term1 and Term2 are turned on, Term3 and Term4 ports are in a disconnected state. At this time, since D5 and D6 are turned on, the RF link connected to the Term3 and Term4 ports can be short-circuited to the ground, thereby improving the port isolation and reducing the impact of the RF link of the Term3 and Term4 ports on other port products. BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Figure 1 This is a diagram of a one-to-three RF switch implemented by a PIN diode;
[0009] Figure 2 This is a RF switch and peripheral circuit diagram built with PIN diodes;
[0010] Figure 3 This is the existing circuit simulation result diagram;
[0011] Figure 4 This is a circuit schematic diagram for improving the port isolation of a radio frequency switch built with a PIN tube;
[0012] Figure 5 This is a circuit simulation diagram for improving the port isolation of a radio frequency switch built with a PIN tube. DETAILED DESCRIPTION
[0013] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.
[0014] Example 1: Figure 4-5 As shown, a circuit for improving the port isolation of a radio frequency switch built with a PIN tube includes an inductor L1, an inductor L2, an inductor L3, an inductor L4, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a diode D1, a diode D2, a diode D3, a diode D4, a diode D5, a diode D6, a resistor R1, a resistor R2 and a resistor R3, one end of the capacitor C1 is connected to the Trem1 port, and the other end is connected to one end of the inductor L1 and the positive electrodes of the diodes D1, D2 and D3, the negative electrodes of the diodes D1, D2 and D3 are connected to one end of the capacitors C2, C3 and C4 respectively, and the other ends of the capacitors C2, C3 and C4 are connected to the Trem2 port, the Trem3 port and the Trem4 port respectively. rem3 port and Trem4 port, one end of the connection between the diode D1 and the capacitor C2 is connected to one end of the inductor L2 and the positive electrode of the diode D4, one end of the connection between the diode D2 and the capacitor C3 is connected to one end of the inductor L3 and the positive electrode of the diode D5, one end of the connection between the diode D3 and the capacitor C4 is connected to one end of the inductor L4 and the positive electrode of the diode D6, the other ends of the inductor L2, the inductor L3 and the inductor L4 are respectively connected to one end of the resistor R1, the resistor R2 and the resistor R3, the other ends of the resistor R1, the resistor R2 and the resistor R3 are connected to the power supply terminal vcc and the two power supply terminals vbb, the other end of the inductor L1 is connected to the ground terminal GND, and the cathodes of the diodes D4, the diodes D5 and the diode D6 are connected to the ground terminal GND.
[0015] Furthermore, the voltage relationship among the power supply terminal vbb, the power supply terminal vcc and the ground terminal GND is vcc<GND<vbb.
[0016] Compared to the previous circuit (see Figure 1) Three PIN diodes D4, D5, and D6 are added. In the figure, the voltage relationship between vbb, vcc, and GND is vcc<GND<vbb. Therefore, when Term1 and Term2 are turned on, Term3 and Term4 ports are in a disconnected state. At this time, since D5 and D6 are turned on, the RF link connected to the Term3 and Term4 ports can be short-circuited to the ground, thereby improving the port isolation and reducing the impact of the RF link of the Term3 and Term4 ports on other port products.
[0017] Use ADS to Figure 4 The circuit is simulated, and the simulation results are shown in Figure 5 From the simulation results, we can see that S(3, 1) = -51.4dB, S(3, 2) = -51.4dB, S(4, 1) = -51.4dB, S(4, 2) = -51.4dB, S(4, 3) = -102.8dB. The isolation of each port has been significantly improved.
[0018] The above description is only a specific implementation method of the present utility model, but the protection scope of the present utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present utility model, which should be included in the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.
Claims
1. A circuit for improving the port isolation of a radio frequency switch built with a PIN tube, characterized in that: It includes an inductor L1, an inductor L2, an inductor L3, an inductor L4, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a diode D1, a diode D2, a diode D3, a diode D4, a diode D5, a diode D6, a resistor R1, a resistor R2 and a resistor R3, one end of the capacitor C1 is connected to the Trem1 port, and the other end is connected to one end of the inductor L1 and the positive electrodes of the diodes D1, D2 and D3, the negative electrodes of the diodes D1, D2 and D3 are connected to one end of the capacitor C2, the capacitor C3 and the capacitor C4 respectively, and the other ends of the capacitors C2, C3 and C4 are connected to the Trem2 port, the Trem3 port and the Trem4 port respectively , one end of the diode D1 and the capacitor C2 is connected to one end of the inductor L2 and the positive electrode of the diode D4, one end of the diode D2 and the capacitor C3 is connected to one end of the inductor L3 and the positive electrode of the diode D5, one end of the diode D3 and the capacitor C4 is connected to one end of the inductor L4 and the positive electrode of the diode D6, the other ends of the inductor L2, the inductor L3 and the inductor L4 are respectively connected to one end of the resistor R1, the resistor R2 and the resistor R3, the other ends of the resistor R1, the resistor R2 and the resistor R3 are connected to the power supply terminal vcc and the two power supply terminals vbb, the other end of the inductor L1 is connected to the ground terminal GND, and the cathodes of the diodes D4, the diodes D5 and the diode D6 are connected to the ground terminal GND.
2. A circuit for improving port isolation of a radio frequency switch constructed with a PIN tube according to claim 1, characterized in that: The voltage relationship among the power supply terminal vbb, the power supply terminal vcc and the ground terminal GND is vcc<GND<vbb.