Date of Award

2017

Document Type

Open Access Thesis

Department

Electrical Engineering

Sub-Department

College of Engineering and Computing

First Advisor

Yinchao Chen

Abstract

Since the Federal Communications Commission’s endorsement of the frequency band of 3.1 – 10.6 GHz in 2002 to be unlicensed for wireless communication applications, various ultra-wideband bandpass filters (UWB-BPFs) have been proposed and designed. Different UWB-BPF configurations were presented in the past years to meet the very strict UWB-BPF specifications in terms of ultra-band requirement, low return loss, high rejection in notched bands. However, most of the previous works are limited by large dimension size, complex geometry, and high production cost.

The major objective of this work is to design a highly compact, simple geometry, and low-cost UWB-BPF, which passes signals in nearly all frequencies in the passband with minimum loss but rejects unwanted WLAN interference signals in the frequency neighborhood of 5.8 GHz. First, an ellipse-shaped UWB-BPF was designed by using a simplified composite right/left handed (SCRLH) resonator to achieve a 3dB bandwidth ranging from 2.94 GHz to 12.83 GHz. Then, two open, curved stepped-impedance stubs were integrated into the UWB-BPF to achieve a notched band in the range of 5.8 GHz, such that the frequency response in the frequency band was sharply notched up to about 35dB attenuation. The finalized UWB-BPF, is simply built up with a commonly used PCB with FR4 substrate and has a dimension of 14mm × 6.2mm. The extracted current density images in the passbands, stop bands, and notch band clearly demonstrate the mechanism of the signal response characteristics of the proposed UWB-BPF.

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