一种性能优化的发夹型微带线滤波器的分析与设计

微带线发夹型滤波器具有结构紧凑、尺寸小、指标优良等优点,在射频和微波通信系统中应用广泛。由于目前设计的多数带通滤波器没有考虑交调畸变的影响,导致通带内波纹起伏较大,衰减严重。本文提出了一种用于抑制通带内波纹起伏及减小带内衰减的新方法。首先,在传统发夹滤波器结构之后加入短路短截线与谐波四分之一波长开路短截线并联谐振结构,能够在不影响有用信号的情况下,很好地抑制交调干扰。接着,通过采用微带径向短截线(MRSTU)扩大抑制干扰带宽,实现通带内宽频带干扰的有效抑制。最后,基于本文方法设计了一款2.3GHz到2.5GHz的五阶发夹型带通滤波器,ADS仿真及版图分析证明了本文方法设计的滤波器具有较为平坦的带通特性,并且将带内衰减降低了近10d B.

Analysis and Design of Hairpin Micro-strip Filter with Novel Performance Optimization

Micro-strip hairpin filter has advantages of compact structure, small size, excellent indicators, and is widely used in RF and microwave communication system. The Micro-strip hairpin filter designed so far does not take into account the influence of the distortion, which causes that the ripple is volatile and attenuation is large within pass-band. This paper proposes a new method that can reduce the ripple and attenuation in-band. First of all, short circuit stub and harmonic quarter-wave open stub parallel resonant structure is added to the traditional hairpin filter structure, which can suppresses the inter-modulation (IM) effectively and does not affect the useful signal. And then, micro-strip radial stub (MRSTU) is used to expand the interference suppression band-width. Finally, a new type of five order hairpin band-pass filter is designed in which pass-band is 2.35GHz to 2.55 GHz. ADS simulations and layout analysis prove the superiority of the proposed method. The results show that the attenuation drops nearly 10 dB in-band.