Filter circuit, multiplexing duplexer and communication equipment

Abstract

The invention discloses a filter circuit, a multiplexing duplexer and communication equipment, the filter circuit comprises two filters and two switches, the two switches are single-pole double-throwswitches, and two ends of the first filter are respectively connected with a first fixed end of the first switch and a first fixed end of the second switch; two ends of the second filter are respectively connected with second fixed ends of the first switch and the second switch; and the movable ends of the first switch and the second switch are respectively used as two ends of the filter circuit.The multiplexing duplexer comprises four 90-degree electric bridges and four filter circuits, signals leaked from a transmitting filter to a receiving filter are divided into two paths by utilizing the phase shifting function of the 90-degree electric bridges, and the phase difference is 180 degrees, so that the signals are mutually counteracted, and the isolation degree is improved.

Description

technical field [0001] The invention relates to the technical field of filters, in particular to a filter circuit, a multiplexer and a communication device. Background technique [0002] The small base station system is an important part of 5G communication, which requires a higher transmission frequency; the filters and multiplexers in the small base station system in the future will move towards small phones, high power capacity, high isolation, and low cost. direction development. [0003] At present, cavity filters and multiplexers are mainly used in base station systems. Filters and multiplexers with cavity structures have small insertion loss, good out-of-band suppression, and high isolation, but their significant disadvantages are size Larger, high processing costs, it is difficult to be widely used in future 5G communications, and bulk acoustic wave filters and multiplexers are characterized by good insertion loss, high out-of-band rejection, and low cost, but their...

AI Technical Summary

Problems solved by technology

[0003] At present, cavity filters and multiplexers are mainly used in base station systems. Filters and multiplexers with cavity structures have small insertion loss, good out-of-band suppression, and high isolation, but their significant disadvantages are size Larger, high processing costs, it is difficult to be widely used in future 5G communications, and bulk acoustic wave filters and multiplexers are characterized by good insertion loss, high out-of-band rejection, and low cost, but their significant disadvantages are power The capacity is poor, the current power capacity is only about 1.5W, it is difficult to meet the requirements of future 5G communication

At the same time, the small base station system requires the coverage area to be as large as possible, so the transmission power is relatively large. If the isolation of the transceiver system is small, the transmitted signal will be coupled to the receiving system, seriously affecting the sensitivity of the receiving system. The isolation has higher requirements, generally greater than 70dB, and it is difficult for ordinary bulk acoustic wave duplexers to meet the requirements

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