Compact Bandpass Filter with high selectivity and wide stopband using Slotted Stepped-Impedance Resonator

In this paper, a Slotted Stepped-Impedance Resonator (SSIR) is proposed. Due to the slots in the low-impedance section of the conventional SIR, the new resonator has a lower fundamental resonance f0 and can provide a potential finite transmission zero fz close to f0. Based on the proposed SSIR, a fourth-order Chebychev BandPass Filter (BPF) is designed at f0=1 GHz. The measured results show that a better than –65 dB rejection is achieved on both the lower and the upper stopband. Moreover, the new filter has a wide –30 dB rejection upper stopband from 1.13f0 to 6.52f0. The fab-ricated filter exhibits a size of The new filter has a planar topology and is easily integrated with modern portable communication systems.     

COMPACT INTERLOCKED-COUPLED FILTER USING FOLDED STEPPED-IMPEDANCE RESONATORS

A microstrip interlocked-coupled bandpass filter is proposed with a markedly compact structure.The low-impedance open-end line of the quarter-wavelength Stepped-Impedance Resonator (SIR) is replaced by...     

Compact triple-passband bandpass filter based on new modified stepped impedance resonators

This study proposed a triple-passband bandpass filter with compact size, low loss and high passband selectivity. The filter includes two coupled stepped impedance resonators (SIRs) and two embedded stub-loaded stepped impedance resonators (SL-SIRs), connected with coupling scheme at the symmetric plane of the filter. The filter is designed to have triple-passband at 2.4, 3.5 and 5.2 GHz for worldwide interoperability for microwave access (WiMAX) applications. By properly tuning the impedance ratio and physical length ratio of the SL-SIRs, the three passbands can be easily determined, at the same time, achieving the high passband selectivity and wide stopband. Besides, the transmission zeros near passband edges of each passband are generated by the proposed filter with cross-coupling structure. The measured results are in good agreement with the full-wave electromagnetic (EM) simulation results.     

DUAL MODE WIDEBAND BAND-PASS FILTER WITH NOTCHED BAND FOR COMMUNICATION SYSTEM

This paper presents a planar microstrip wideband dual mode Band-Pass Filter (BPF) from 2 GHz to 3.4 GHz with a notched band at 2.62 GHz.The dual mode band-pass filter consists of a ring resonator with ...     

高温超导谐振器与滤波器的微调研究

高温超导滤波器采用的基底的介电常数和厚度与模拟设计值往往存在一定差异,从而导致实际制作的滤波器的中心频率和频带偏离设计值。本文提出了解决这一问题的新思路,在原有高温超导滤波器上进行微调,即对组成滤波器的每个谐振器的局部进行相同的微小结构改变,使谐振器频率偏移,进而使滤波器的整个频带发生偏移。并利用该方法对多种谐振器和四节前向耦合高温超导滤波器进行了模拟,发现数值模拟数据与理论曲线符合得很好。这一方法对于窄带高温超导滤波器尤其具有重要的意义。