CN-122001314-A - Single-pole double-throw switch filter assembly based on LTCC technology

CN122001314ACN 122001314 ACN122001314 ACN 122001314ACN-122001314-A

Abstract

The invention discloses a single-pole double-throw switch filter assembly based on LTCC technology. The switching circuit and the LTCC resonator are integrated integrally, and the on and off states of the switching diode are controlled by externally applied direct current bias voltage in the working process. When the diode is in a conducting state, parasitic inductance and capacitance form series resonance, and the equivalent coupling admittance converter of the resonator can be reversely equivalent to open circuit, so that the branch signal is cut off, and channel isolation is realized. The structure realizes the low insertion loss characteristic by utilizing the SIW waveguide integration form on one hand, and effectively improves the stop band suppression degree by introducing cross coupling topology on the other hand. The whole circuit has the characteristics of compact structure, low loss, high isolation, excellent out-of-band rejection performance and the like, and can meet the requirements of 5G and future high-speed wireless communication systems.

Inventors

XU JINXU
ZHANG XIUYIN
Huang Chanqi
WANG WEIXI
DU CHANGYUAN

Assignees

扬州江嘉科技有限公司

Dates

Publication Date: 20260508
Application Date: 20251130

Claims (8)

1. A single-pole double-throw switch filter assembly based on LTCC technology is characterized in that a three-dimensional integrated structure with a LTCC filter and a switch circuit in a collaborative fusion mode is formed.
2. The LTCC technology-based single pole double throw switch filter assembly of claim 1, wherein the filter switch has a plurality of circuit layers, a plurality of via layers, a plurality of ground layers, an input/output layer, and a switch circuit layer; one circuit layer of the circuit layers is provided with a capacitor loading SIW filter circuit, the other two circuit layers are provided with quarter-wavelength strip line switch circuits, and the capacitor loading SIW filter circuit is connected with the quarter-wavelength strip line switch circuits.
3. The single-pole double-throw switch filter assembly based on the LTCC technology according to claim 2, wherein the switch circuit layer is located in the first layer circuit and comprises a switch diode D1, a switch diode D2, a switch diode D1-1 and a switch diode D2-1, a bias capacitor C2, a bias capacitor C1-1, a bias capacitor C2-1, an inductor L2, an inductor L1-1, an inductor L2-1, a direct current voltage VDD1 and a direct current voltage VDD2, wherein the switch diode D1 is connected with a resonator R3 through a via hole, the switch diode D2 is connected with the resonator R2 through a via hole, the switch diode D1-1 is connected with the resonator R3-1 through a via hole, the switch diode D2-1 is connected with the resonator R2-1 through a via hole, the direct current power supply VDD1 is connected with one end of the inductor L1, the inductor L2-1 is connected with one end of the inductor L2, the other end of the inductor L1-1 is connected with one end of the inductor L2-1, the other end of the inductor L1 is connected with one end of the inductor C1 and the other end of the bias capacitor C1-1 is connected with one end of the inductor C1-1, and the other end of the bias capacitor C2 is connected with one end of the positive end of the inductor C1-2 is connected with one end of the inductor C1-2-1, and the other end of the bias capacitor is connected with the other end of the positive end of the inductor C1-2-1-2.
4. A single pole double throw switch filter assembly according to claim 3, wherein metal walls W1 and W1-1 are provided for coupling isolation between resonators R2 and R2-1, and metal walls W3 and W3-1 are provided for coupling isolation between resonators R3 and R3-1.
5. A single pole double throw switch filter assembly according to claim 3, wherein said ground layer comprises a ground metal layer G1, a metal electrode layer G2 and a third metal layer G3; the other ends of the bias capacitors C1 and C1-1 are connected with the grounding metal layer G1 through common via holes, and the other ends of the bias capacitors C2 and C2-1 are connected with the grounding metal layer G1 through via holes; The metal electrode layer G2 is printed on the surface of the element to shield the influence of external electromagnetic fields on an internal circuit; and the third metal plate G3, the DC voltages VDD1 and VDD2 of which are electrically connected with an external PCB test board, is fed into the state of the DC voltage regulating switch diode.
6. A single pole double throw switch filter assembly according to claim 3, wherein a first input signal metal lead IN is directly coupled to a first resonator R1, a first output signal metal lead Out1 is directly coupled to a resonator R2 for outputting a first branch signal, the first branch signal is through the resonator R1, the resonator R2, the resonator R3 and the resonator R4, and a second branch signal is through the resonator R1, the resonator R2-1, the resonator R3-1 and the resonator R4, and the on and off states of the two branches are controlled by adjusting the on and off states of the diodes, respectively.
7. The LTCC technology based single pole double throw switch filter assembly of claim 6, wherein all of the vias, all of the resonators, all of the switch circuit elements are symmetrically distributed about the first input signal metal lead IN, resonator R1 and resonator R4.
8. The LTCC technology-based single pole double throw switch filter assembly of claims 1-7, wherein the vias, striplines, and metal pads in the filter switch are copper, and the component size and trace width are in the order of microns.

Description

Single-pole double-throw switch filter assembly based on LTCC technology Technical Field The invention belongs to the technical field of wireless communication, and particularly relates to an integrated direction of microwave passive devices and active devices, in particular to a single-pole double-throw (SPDT) filter switching circuit with low insertion loss, high suppression degree, miniaturization and high isolation degree. Background Low temperature cofired ceramics (LTCC, low Temperature Co-FIRED CERAMIC) are a mature technology that is widely used in high frequency and high density electronic packaging. The process prepares the low-temperature sintered ceramic powder into a green ceramic tape with accurate thickness and compact structure, and forms a required circuit pattern on the surface of the green ceramic tape by adopting precise processes such as laser drilling, micropore grouting, conductor paste printing and the like. Then, by lamination and high-temperature co-firing, passive structures such as metal wires, through holes and the like can be embedded in the matrix, and Integrated Circuits (ICs) and active devices are attached to the surface after sintering, so that the three-dimensional integration of the passive devices and the active devices is realized. LTCC technology has the advantages of high quality factor (Q value), excellent heat dissipation performance and reliability, good high-temperature stability, mechanical shock resistance and the like, and has become an important way for integrating microwave and millimeter wave devices. Conventional filters are typically combined with the switch in a cascaded fashion, i.e., the filter is placed in front of or in the back of the switch. The discrete architecture is simple in design, but is easy to cause the volume of the radio frequency front end to be overlarge, and is unfavorable for miniaturization and high integration of the system. Meanwhile, the cascade connection can also introduce impedance mismatch, so that signal reflection and loss are increased, and overall performance is affected. In order to meet the requirements of 5G and future wireless communication systems on low loss, miniaturization and high integration level, the invention provides a capacitive loading type waveguide integration (SIW) structure single-pole double-throw filter switch fusion circuit based on the LTCC technology. The design fully utilizes the advantages of the three-dimensional laminated structure of the LTCC, and the switch circuit is embedded into the multilayer ceramic matrix to realize integrated integration, so that the circuit size is obviously reduced, the interconnection loss is reduced, and the isolation and the reliability of the system are improved. The scheme is particularly suitable for the 5G small base station and the compact radio frequency front end module, and has good application potential and industrialization prospect. Disclosure of Invention The invention discloses a single-pole double-throw switch filter component based on a low temperature co-fired ceramic (LTCC) technology, which is designed based on the co-fusion of a Substrate Integrated Waveguide (SIW) filter and a switch circuit. The invention is realized by the following technical scheme: a single-pole double-throw switch filter assembly based on LTCC technology forms a three-dimensional integrated structure with the LTCC filter and a switch circuit in a collaborative fusion mode. Further, the filter switch is provided with a plurality of circuit layers, a plurality of via layers, a plurality of grounding layers, an input/output layer and a switch circuit layer; one circuit layer of the circuit layers is provided with a capacitor loading SIW filter circuit, the other two circuit layers are provided with quarter-wavelength strip line switch circuits, and the capacitor loading SIW filter circuit is connected with the quarter-wavelength strip line switch circuits. The switching circuit layer is located in the first layer circuit and comprises a switching diode D1, a switching diode D2, a switching diode D1-1 and a switching diode D2-1, wherein the biasing capacitor C1, the biasing capacitor C2, the biasing capacitor C1-1 and the biasing capacitor C2-1 are connected with the first layer circuit, the first layer circuit comprises an inductor L1, an inductor L2, an inductor L1-1, an inductor L2-1, a direct-current voltage VDD1 and a direct-current voltage VDD2, the switching diode D1 is connected with a resonator R3 through a through hole, the switching diode D2 is connected with the resonator R2 through a through hole, the switching diode D1-1 is connected with the resonator R3-1 through a through hole, the switching diode D2-1 is connected with the resonator R2-1 through a through hole, the switching diode D2-1 is connected with one end of the inductor L1, the direct-current power supply VDD1 is connected with one end of the inductor L2, one end of the inductor L1 is connected with o