Abu Nasar Ghazali

Band Notched UWB-BPF Based on Broadside Coupled Microstrip/CPW Transition

ABSTRACT A planar band notched ultra-wideband (UWB) bandpass filter based on broadside coupling of microstrip/co-planar waveguide (CPW) transition is proposed and implemented. The UWB filter topology is made up of microstrip lines on the top coupled in broadside fashion to an open ended CPW in the ground plane. Dual narrow notches at 5.2 and 7.9 GHz are implemented by etching two meander shaped defected ground structures in the CPW under the microstrip lines. A wideband stopband for improved isolation is obtained with the suppression of spurious harmonics by the attenuation poles generated by the spur line structures embedded in the input and output feeding lines. The proposed structure exhibits good frequency characteristics and is of compact size.

Planar UWB Filter with Multiple Notched Band and Stopband with Improved Rejection Level

Abstract Analysis and realization of a microstrip-based planar ultra-wideband (UWB) filter with integrated multiple notch elimination property and simultaneously extended upper stopband is proposed. Initially, a UWB filter based on back-to-back microstrip-to-CPW technology is designed. Later, multiple spiral defected ground structures (DGS) are embedded to obtain multiple passband notches. Further, double equilateral U (DEU)-type DGS are used to improve upon the rejection level in upper stopband. The multiple passband notches are results of embedded spiral-shaped DGS (SDGS), while extended upper stopband is the outcome of suppressed higher-order spurious harmonics. The flexible dual-attenuation poles of DEU-shaped DGS suppress the stopband harmonics and widen the stopband. An approximate lumped equivalent circuit model of the proposed filter is modelled. The filter is compact and its layout measures 25.26 mm × 11.01 mm. The measured result is in good agreement with the full-wave electromagnetic (EM) simulation and circuit simulation.

A Compact UWB Filter with Notched Band and Suppressed Stopband Using DGS

AbstractA microstrip-based Ultra-Wideband Bandpass Alter with a controllable notch and suppressed stopband is proposed. Dumbbell-shaped defected ground structure (DGS) etched in the ground and the double equilateral-U (DEU) DGS units under the input and output feeding lines provide the controllable notch and suppressed stopband, respectively. For optimum design of both the DGS (Dumbbell and DEU), a notch at WLAN frequency of 5.8 GHz and simultaneous stopband till 18 GHz is reported. Experimental results are in favor of the simulated data.

Microstrip based UWB filter with controllable multiple notches and extended upper stopband

Microstrip based ultra-wideband (UWB) bandpass filter (BPF) with controllable triple notches and simultaneously extended upper stopband is proposed. Initially an UWB filter based on back-to-back microstrip to co-planar waveguide (CPW) technology is constructed. Band notch property is integrated into the UWB filter by implementing complementary split ring resonators (CSRR) based defected ground structures (DGS) in the ground of this filter. Double equilateral-U (DEU) DGS etched under the input and output feeding lines suppress the spurious stopband harmonics and extend the stopband. An approximate lumped equivalent circuit model of the proposed structure is presented. Full wave and circuit simulations are in good agreement with measured results.

A Compact Broadside Coupled Notched Band UWB Filter with Wide Upper Stopband

ABSTRACT A broadside coupled ultra-wideband (UWB) bandpass filter (BPF) with notched band and wide upper stopband is proposed and implemented. Initially, a broadside coupled UWB filter structure with good passband characteristics is developed. To this, split ring resonator (SRR) metal lines of half guided waveguide length are coupled to generate passband notch. Later, stub lines are embedded in the input and output (I/O) feeding lines whose attenuation poles suppress the spurious harmonics and widen the stopband. Finally, the proposed structure is fabricated and measured which establishes the authenticity of the full-wave electromagnetic response. The passband extends from 2.85 to 11.3 GHz with stopband of width 18 GHz and depth greater than 18 dB. The variation of group delay is less than 0.42 ns in the passband. The proposed structure is small in size measuring 11.08 × 11.7 mm2.

UWB-BPF with Application Based Triple Notches and Suppressed Stopband

An ultra-wideband (UWB) bandpass fllter (BPF) with application oriented triple notches and simultaneously suppressed stopband is proposed. Implementing complementary split ring resonator (CSRR) and novel complementary meandered folded split ring resonators (CMFSRR) shaped defected ground structures (DGS) in the ground of proposed structure generates the triple notch in the UWB passband. The notch positions are functions of CSRR/CMFSRR proflle dimensions. Stopband is suppressed using the dual attenuation poles generated by the double equilateral-U (DEU) shaped DGS. An approximate lumped equivalent circuit model of the proposed fllter is presented. Measured results obtained are in good agreement with the equivalent circuit model and full wave electromagnetic (EM) simulation. The fllter is small in size with an overall area of 26:06mm£ 11mm.