Amit Ranjan Azad

Synthesis of cross-coupled resonator filters using comprehensive learning particle swarm optimization (CLPSO) algorithm

This paper presents the synthesis of coupling matrix of cross-coupled resonator filters using comprehensive learning particle swarm optimization (CLPSO) algorithm. The CLPSO algorithm does not require gradient information of the fitness function under consideration. The coupling topology of the filter is incorporated in the optimization process to eliminate the need of similarity transformations of the coupling matrix. The CLPSO algorithm is applied to synthesize third- and fourth-order cross-coupled resonator filters.

Compact differential wideband bandpass filter

A compact differential wideband bandpass filter (BPF) with good common mode suppression is presented in this paper. The proposed filter consists of a four port two stage branch line differential mode filter. This filter is analyzed by bisecting it into a two port network, which results in a bandpass or bandstop filtering response under differential or common mode excitations, respectively. The length and widths of the stubs can be tuned to obtain desired passband and stopband of the differential BPF. The proposed differential filter is fabricated and measured. The measured results are in good agreement with the simulated results.

Cross-coupled substrate integrated waveguide filter with enhanced electric coupling

This paper presents an electric coupling structure based on double-layered SIW cavity resonators which provides enhanced coupling coefficient. Electric coupling is achieved by inserting two short-ended striplines between two SIW cavities. The electric coupling depends on the width of the stripline. The proposed structure can achieve coupling coefficient more than 0.12. In order to validate the proposed structure, a fourth-order cross-coupled filter having center frequency of 9.7 GHz and 3-dB bandwidth of 13% has been designed.

Compact UWB bandpass filter with notched band using multiple-mode resonator

In this paper, a compact ultra-wideband (UWB) bandpass filter (BPF) with notched band is proposed. The basic quintuple mode UWB bandpass filter is based on stub loaded multi-mode resonator (MMR) and two interdigital coupled lines. Two embedded slotline based split-ring resonators (SRRs) are introduced in the ground plane near the I/O feed lines in order to generate the notch band around 8.7 GHz. The design BPF has passband insertion loss of 1.6 dB, return loss greater than 12 dB and fractional bandwidth of 110 %. The proposed filter with has a compact size of 22.22 mm × 13.13 mm.