Micro-strip dual-band adjustable band-pass filter based on folding split ring

Abstract

The invention discloses a micro-strip dual-frequency adjustable band-pass filter based on a folding split ring. Resonator coupling is adopted to form a dual-frequency band-pass filter, varactors are respectively loaded at an opening of an open-loop resonator and a terminal of a stepped impedance resonator, and the capacitance value is changed by changing an external voltage, so that the resonant frequency of the filter is changed, and dual frequency bands of the filter are independent and adjustable.

Description

technical field [0001] The invention belongs to the technical field of filters, in particular to a microstrip dual-band adjustable band-pass filter based on folded split rings. Background technique [0002] As a core component in wireless communication systems, microwave filters play a role in frequency band selection in radio frequency communication systems. With the rapid development of modern wireless communication systems, microwave filters are also facing great challenges. The communication system is becoming smaller and smaller, and the space left for the filter is also reduced. The contradiction with the miniaturization is that the multi-function of the modern communication system makes the communication system cover more and more frequency bands, so that the number of filters Multiplied. Tunable filters came into being under this background. Tunable filters can effectively solve the contradiction between the bulky size brought by the multifunctional communication s...

AI Technical Summary

Problems solved by technology

[0003] Since the tunable filter is researched on the basis of the filter, although the development is relatively late, the progress is relatively rapid.

At the beginning of the research on tunable filters, the research and production personnel mainly focused on single-frequency tunable filters. For example, foreign scholar Y. Band-pass filters, but with the rapid development of modern wireless communication systems, single-band tunable filters have largely been unable to meet the needs of communication systems

Therefore, the research on dual-frequency tunable filters is becoming more and more important. Domestic scholars have designed and implemented a dual-frequency tunable filter that works at 0.8-1.02GHz and 2.02-2.48GHz by means of branch-loaded impedance resonators. However, the designed filter is loaded with more varactor diodes, resulting in a higher insertion loss in the final designed tunable filter. The frequency band 2.4GHz-2.6GHz and the frequency band 3.4GHz-3.6GHz are widely used frequency band, so designing a tunable filter that works in these two frequency bands has great practical application value

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