Low Profile Metamaterial Band-Pass Filter Loaded with 4-Turn Complementary Spiral Resonator for WPT Applications

TL;DR

This paper introduces a compact, low-loss metamaterial band-pass filter with a 4-turn complementary spiral resonator, optimized for wireless power transfer at 730 MHz, demonstrating high stopband attenuation and practical fabrication results.

Contribution

It presents a novel low-profile MBPF design with interdigital capacitor loading, achieving improved stopband performance for WPT applications.

Findings

Achieved over 52 dB attenuation in the stop band

Validated design with high agreement between simulation and measurement

Demonstrated suitability for wireless power transfer systems

Abstract

In this paper, a very compact and low insertion loss metamaterial band-pass filter (MBPF) at the center frequency of f0=730 MHz is proposed, based on the rectangular-shape 4 turn complementary spiral resonators (4 CSR). The proposed MBPF consists of an interdigital capacitor as a series capacitance in the top layer, leading to improve the stopband performance in the pass band range of 700 to 760 MHz, which makes it suitable for wireless power transfer (WPT) systems by rejecting unwanted signals. In order to validate the performance of the proposed technique, the MBPF is fabricated on the RO-4003 substrate and great agreement is achieved between simulated and measured results. The stop band attenuations of greater than 52 dB and 20 dB are obtained around the 0.8xfcl (lower cutoff frequency) and 1.2xfcu (upper cutoff frequency), respectively.