UWB Bandpass Filter with Dual Notched Bands Using T-Shaped Resonator and L-Shaped Defected Microstrip Structure.

Xuemei Zheng,Yuwen Pan,Tao Jiang

doi:10.3390/mi9060280

Xuemei Zheng, Yuwen Pan + Show 1 more

Open Access

https://doi.org/10.3390/mi9060280

Copy DOI

Abstract

In this paper, an ultra-wideband (UWB) bandpass filter (BPF) with dual notched bands using a T-shaped resonator and L-shaped defected microstrip structure (DMS) is proposed and fabricated. First, the principle of generating notched bands by using a T-shaped resonator and L-shaped defected microstrip structure to determine the size parameters of the structure is analyzed. High frequency structure simulator (HFSS) software is used to analyze the performance of the filter, and advanced design system (ADS) is used to extract the equivalent circuit model parameters. The two simulation results are consistent, which further verifies the correctness of the circuit model. Finally, the filter is fabricated and measured. The measured results are in good agreement with simulated results, demonstrating good insertion loss and return loss. The proposed filter has dual independently controllable notched bands which are implemented by coupling the T-shaped resonator to the transmission line and by etching the L-shaped defected microstrip structure respectively. The proposed filter can suppress dispensable bands at 3.5 GHz and 7.5 GHz in WiMAX band and X-band to improve the performance of the ultra-wideband communication system. By adjusting the parameters of the T-shaped resonator and L-shaped defected microstrip structure, the UWB bandpass filter with dual notched bands working at WiMAX band and X-band can be designed and applied to the wireless communication system.

Highlights

Ultra-wideband (UWB) communication systems are widely used in wireless communication because of low cost and high data rate
The ultra-wideband (3.1–10.6 GHz) frequency spectrum was announced by the Federal Communications Commission in 2002 [1] for unlicensed indoor and hand-held commercial applications. ultra-wideband filters, as one of the key components of the radio frequency front-end, directly affect the quality of communication systems
The notch bands are generated by introducing a resonance unit, such as a stepped impedance resonator (SIR) [2,3] and multi-mode resonator (MMR) [4,5,6,7,8,9]

Summary

Introduction

Ultra-wideband (UWB) communication systems are widely used in wireless communication because of low cost and high data rate. In order to remove interference from WiMAX and satellite communication bands, a dual notched ultra-wideband bandpass filter is proposed in this paper. A dual notched ultra-wideband bandpass filter using a T-shaped resonator and L-shaped defect microstrip structure is proposed and fabricated. The first and second notched band functions are respectively implemented by coupling the T-Shaped resonator to the transmission line and etching the L-shaped defect microstrip structure on the bandpass filter. We will discuss the design of the ultra-wideband filter with dual notched bands and study the frequency rejection function based on a T-shaped resonator and L-shaped defect microstrip structure. By adjusting the parameters of the T-shaped resonator and L-shaped defect microstrip structure, the ultra-wideband bandpass filter with dual notched bands working at WiMAX band and X-band can be designed and applied to the wireless communication system

Filter Design

Conclusions