一种具有边带陡峭特性的超窄带滤波器

A Side-Band Suppressed Ultra-Narrow-Band Filter

应用LTCC技术,设计了一款带通滤波器。采用开口环谐振结构作为基本谐振单元,利用谐振级之间的耦合产生传输零点,实现边带抑制。给出了开口环谐振结构的等效电路分析,滤波器的通带中心频率为23.2GHz,3-dB带宽为600 MHz,具有很窄的相对带宽,3-dB相对带宽仅为2.6%。对滤波器进行仿真和优化,结果表明,通带22.9-23.5GHz内插损小于3dB,低阻带10-21.1GHz的衰减大于45dB,高阻带25.3-40GHz的衰减均大于30dB。该滤波器的尺寸为4mm×3.5mm×0.45mm,具有非常好的窄带特性和边带抑制特性。

A side-band suppressed ultra-narrow-band filter with a good narrow-band characteristics was designed in a LTCC technology. The filter used an open-loop stripline resonator as a basic resonator unit by using coupling between resonators to generate zeros to obtain sideband suppression. The equivalent circuit of the resonator was given. Its central frequency was 23.2 GHz, the 3 dB bandwidth was 600 MHz, and the relative bandwidth was only 2.6%. The proposed resonator was simulated and optimized, and the results showed that the pass-band insertion loss was less than 3 dB from 22.9 GHz to 23.5 GHz, the low stop-band attenuation was more than 45 dB from 10 GHz to 21.1 GHz, and the high stop-band attenuation was more than 30 dB form 25.3 GHz to 40 GHz. The filter＇s size was 4 mm N 3.5 mm × 0.45 mm. The filter had a good narrow-band characteristics and a good sideband suppression performance.