Dual-mode high-performance balance band-pass filter based on E-shaped resonators

Abstract

The invention discloses a dual-mode high-performance balance band-pass filter based on E-shaped resonators. The dual-mode high-performance balance band-pass filter comprises input port feeder lines, output port feeder lines, a first E-shaped resonator and a second E-shaped resonator positioned on the upper surface of a dielectric substrate and a metal ground plate positioned on the lower surface of the dielectric substrate. The first E-shaped resonator and the second E-shaped resonator are symmetrical surface branch loaded dual-mode resonators; the input port feeder lines comprise a first input port feeder line and a second input port feeder line which are symmetrically connected with each other; the output port feeder lines comprises a first output port feeder line and a second output port feeder line which are symmetrically connected with each other; and each of the first E-shaped resonator and the second E-shaped resonator comprises a half wavelength resonator and a symmetrical surface branch loading unit. The dual-mode high-performance balance band-pass filter has the characteristics of miniaturization, high common mode rejection, high selectivity, low loss and the like, and is very suitable for modern wireless communication systems.

Description

technical field [0001] The invention relates to the technical field of microwave passive devices, in particular to a dual-mode high-performance balanced bandpass filter based on an E-type resonator. Background technique [0002] In recent years, with the development of Modular Building Block (MBB) and Monolithic Microwave Integrated Circuit (MMIC), low cost, high integration, and miniaturization have become very important considerations in the integrated design of modern wireless communication systems. . The balanced filter is an independent microwave passive device, which has higher environmental noise immunity, better dynamic range, and lower electric field interference than the dual-port filter. The balanced filter in the radio frequency circuit can Transmits differential mode signals and rejects common mode signals. A high-performance balanced filter can not only effectively reduce the size of the system, but also simplify the complexity of the system design, thereby f...

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Problems solved by technology

Although the design theory of this design method is relatively simple, because the structure needs to be loaded with lumped elements, the structure processing is complicated and the error increases

[0004] Document 2 (WenjieFengandWenquanChe, NovelwidebanddifferentialbandpassfiltersbasedonT-sharpedstructure, IEEE Transaction on Microwave Theory Technique, 2012,60,(6):1560–1568) proposed a resonator based on a T-shaped structure loaded with open-circuit stubs and short-circuit stubs to achieve balanced output of signals and dual-mode bandpass characteristics. Although this design method is relatively simple in structure , but the common mode rejection effect is only 14.5dB, and its differential mode out-of-band rejection is poor

[0005] Document 3 (Li Yang, Wai-WaChoi, Kam-WengTam, and LeiZhu, Balanced dual-bandband pass filter with multiple transmission zeros using double short-ended resonator coupled line, IEEE Transaction on Microwave Theory Technique, 2015,63,(7): 2225–2232) proposed double-terminal short-circuit resonators and end-loaded parallel coupling structures to realize dual-passband balanced filters. This design concept is relatively novel, but its passband differential loss is relatively large. large, and the circuit size is large

[0006] It can be seen from the above that the structure of the balanced filter in the prior art is relatively complicated, and it is not easy to process and integrate; the common mode suppression effect is not good enough; the filter selectivity is poor, the insertion loss is large, and the circuit size is large, which is not suitable for modern wireless communication. system

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