关键词: 滤波器, 频偏, 涂胶

Abstract: This paper presents a method of applying fluoroplastic sealant on the surface of planar circuit to adjust the deviation of filter center frequency. Firstly, the variation trend of various performance parameters of 12-order hairpin band-pass filter before and after it was coated with fluoroplastic sealant was simulated and analyzed. Then, fluoroplastic sealant was coated on the sample surface of filter, and the characteristics of band-pass filter before and after the coating were tested. The test results were basically consistent with the simulation results, and it was found that the center frequency of the filter after being coated with fluoroplastic sealant moved to low frequency, the in-band insertion loss increasing slightly, the passband width, in-band fluctuation and out-of-band rejection did not change significantly, which verified the feasibility of the method.

Key words: filter, frequencydeviation, applysealant