Impedance Resonator Bandpass Research Articles

Novel Stepped Impedance Microstrip Bandpass Filters for Radar Applications

In this paper, the design and realization of A Novel Microstrip Stepped Impedance Resonator Bandpass Filters with two selected center frequencies (f0) 12GHz and 16GHz presented. For The design of Band pass Filters “Rogers 6035HTC" substrate material with relative dielectric constant of 3.55, Standard thickness of 0.020” (0.508mm), thickness of pec is 0.035mm and simulated on High Frequency System Simulator (HFSS). Both the designed filters performances are discussed and compared with literature. The designed Stepped Impedance microstrip BPFs have insertion loss of <1dB with the optimal average performance of 37% and 32% FBW, and return losses are 47 dB and 32dB, which is reported better when compared with the reference designs.

Wide‐stopband and high selectivity step impedance resonator bandpass filter using T‐network and antiparallel coupled line

A wide-stopband attenuation with high-selectivity step impedance resonator (SIR) bandpass filter (BPF) is presented in this study. The T-network stubs are used to produce transmission zeros (TZs) close to the centre frequency ( f 0 ) with a high-selectivity. Moreover, the antiparallel coupled lines can produce a TZ at spurious frequency of conventional SIR BPF for all step impedance ratio ( K ). For the validation, a half-wavelength ( λ /2) SIR BPF with T-network stubs at the input/output ports was designed at f 0 of 2.6 GHz. From the experiment, the insertion and return losses at f 0 were determined to be 0.91 and 21.25 dB, respectively. The insertion and return losses were better than 1.1 and 16.5 dB, respectively, of the 180 MHz bandwidth. The TZ frequencies ( fZ 1 , fZ 2 , and fZ 3 ) were located at 1.69 GHz (0.63 f 0 ), 2.98 GHz (1.12 f 0 ), and 3.17 GHz (1.19 f 0 ), respectively, with a high selectivity. The stopband attenuation was better than 25 dB from DC to 2.23 GHz and from 2.89 to 9.82 GHz.

Method of determining feed positions in coupled half-wavelength stepped impedance resonator bandpass filter

In this study, the input impedance of coupled half wavelength stepped impedance resonator bandpass filter with directly tapped feed structure is deduced, and the method of determining the feed positions in the filter is proposed by using the concept of impedance matching. Two microstrip bandpass filter examples are described for demonstrating the procedure. The simulated and measured results indicate that the proposed method is an effective way for designing similar filters.

Stepped impedance resonator bandpass filters using tapped‐line for controlling spurious response

AbstractA stepped impedance resonator bandpass filter was designed and implemented, combining with the tapped‐line structure. The measured bandpass filters at the center frequency of 2.0 GHz has the characteristics: the insertion loss S21 = −2.98 dB, BWR is 15.1%, and the transmission zeros occurred at 2.62 GHz with −48.5 dB. Especially, the wider rejection of −20 dB can be obtained form 2.4 to 8.2 GHz from the proper position of tapped‐line I/O. The designed filter shows the excellent abilities to shift and suppress the spurious response by properly designing the structure of the resonator. The proposed filter was designed and fabricated, and the performances closely matched the simulation results. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 40: 481–484, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20010

Microstrip stepped impedance resonator bandpass filter with an extended optimal rejection bandwidth

Bandpass filters with an optimal rejection bandwidth are designed using parallel-coupled stepped impedance resonators (SIRs). The fundamental (f/sub o/) and higher order resonant harmonics of an SIR are analyzed against the length ratio of the high-Z and low-Z segments. It is found that an optimal length ratio can be obtained for each high-Z to low-Z impedance ratio to maximize the upper rejection bandwidth. A tapped-line input/output structure is exploited to create two extra transmission zeros in the stopband. The singly loaded Q(Q/sub si/) of a tapped SIR is derived. With the aid of Q/sub si/, the two zeros can be independently tuned over a wide frequency range. When the positions of the two zeros are purposely located at the two leading higher order harmonics, the upper rejection band can be greatly extended. Chebyshev bandpass filters with spurious resonances up to 4.4f/sub o/, 6.5f/sub o/, and 8.2f/sub o/ are fabricated and measured to demonstrate the idea.