Modelling and validation of a simple and compact wide upper stop band ultra-wideband bandpass filter

Abstract

A compact ultra-wideband (UWB) bandpass filter (BPF) is proposed based on end coupled microstrip transmission line, defected ground structure and defected microstrip structure. The experimental filter shows a fractional bandwidth of 110% at a centre frequency, with two observable transmission zeros (attenuation poles) at 2.1 and 11.7 GHz. Measured results exhibit an UWB passband from 3.02 to 10.6 GHz with mid-band insertion loss of 1.8 dB and group delay variation <0.45 ns. The BPF achieves a wide stopband with < −18 dB attenuation up to 20 GHz.

Keywords

• band-pass filters
• ultra wideband technology
• coupled transmission lines
• microstrip couplers
• microstrip lines
• defected ground structures
• microstrip filters
• microwave filters
• UHF filters
• compact ultrawideband bandpass hlter
• UWB BPF
• end coupled microstrip transmission line
• defected ground structure
• defected microstrip structure
• observable transmission zeros
• attenuation pole
• midband insertion loss
• frequency 2.1 GHz
• frequency 11.7 GHz
• loss 1.8 dB