Dual Notched Multilayer Broadside Coupled Ultra-Wideband Bandpass Filter with Folded Meander Slots

Abstract

This paper presents a dual-notched multilayer broadside-coupled ultra-wideband (UWB) bandpass filter with folded meander slots, designed for efficient interference mitigation in UWB systems using multilayer printed circuit board (MPCB) technology. The filter employed a microstrip-coplanar waveguide (CPW) architecture with half-wavelength stepped impedance resonators (SIR) on the upper and lower layers connected vertically via a CPW-rectangular patch resonator on the central layer. The UWB performance is achieved through tight coupling, whereas folded meander slots at the input and output patches create dual notched bands to eliminate interference from narrowband systems, allowing precise frequency adjustment. High-frequency simulations and parametric analyses optimized the filter's dimensions and notch placements, achieving a 96.5% 3 dB fractional bandwidth across the UWB spectrum, with sharply notched bands at 6.0 GHz and 7.6 GHz, attenuated by 19.89 dB and 19.51 dB, respectively, eliminating WLAN and X-band satellite signals. Experimental tests on the RT/Duroid 5880 substrates confirmed the simulated data, validating the minimal insertion loss, enhanced selectivity, and compact design configuration. This study offers a robust solution for interference reduction with significant potential for use in existing UWB wireless communication networks