Suspended Stripline Ultra-Broadband Tunable Zero Bandpass Filter

Abstract

The invention discloses a suspended stripline ultra-wideband adjustable zero-point bandpass filter, which has small area, high integration and excellent standing wave performance. The present invention is realized through the following technical scheme: at least two resonators and a double-layer metallized coupling via are arranged on the front and back of the dielectric substrate, and each resonator is composed of The main resonator on one side and the resonator loading capacitor on the other side are jointly formed. The resonator loading capacitors of all resonators are connected to the metal ground on both sides of the dielectric substrate; the transmission lines at both ends are realized through a metallized via hole. Each resonator can adjust the self-resonant frequency of the resonator by adjusting the size of the resonator loading capacitance on the back of the dielectric substrate. Increasing the size of the capacitive loading part will shift the self-resonant frequency of the resonator to the low-frequency direction, and reducing the capacitive loading size on the back of the resonator will shift the self-resonant frequency of the resonator to the high-frequency direction.

Description

technical field [0001] The invention relates to a radio frequency microwave filter, in particular to a bandpass filter which can be widely used in the front end of a radio frequency communication system. Background technique [0002] Filters are one of the indispensable devices in wireless communication systems. With the development of new technologies in the radio frequency / microwave field, filters are also developing towards high performance, miniaturization, high power capacity, light weight and low cost. In the communication system, the signal will be interfered by the environmental noise signal outside the system, as well as the harmonic influence in the system due to the nonlinearity of the system, which will significantly reduce the communication quality of the communication system. In order to suppress the interference signal outside the system and the harmonic signal generated by nonlinearity in the system, it is necessary to add a filter to the system to ensure th...

AI Technical Summary

Problems solved by technology

Using cascaded high- and low-pass filters is equivalent to using two filters to realize the function of a band-pass filter, which is too bulky; microstrip multi-mode resonance technology is one of the mainstream technologies for realizing ultra-wideband filters, but due to It has only one resonator, and it is difficult to introduce a transmission zero point outside the passband in terms of structure; low-temperature co-fired ceramic technology and liquid crystal polymer technology are complex in processing and high in cost, and it is difficult to introduce a transmission zero point

After simulation, it is found that the filter response is not good, and the standing wave is relatively large

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