Compact Broadband Dual-Band Filtenna With High Selectivity for Vehicle Application
Di Pang, Huafeng Su, Xiao Peng Li, Hui Liang Xu, Xiu Yin Zhang
Abstract
This paper presents a compact dual-band filtenna with high selectivity and seven controllable radiation nulls for vehicle application. The proposed filtenna is composed of three dual-mode resonators and a feedline, which are etched on a 3D hollow substrate. To achieve dual-band responses with compact size, three dual-mode resonators are investigated, which feature broad band and controllable frequency ratio to fully cover WIFI bands. For miniaturization, filtering responses are realized by designing multi-path couplings between resonators and the feedline. Without increasing antenna size and extra filtering circuits, seven controllable radiation nulls are realized beside pass-bands. Therefore, the proposed filtenna possesses dual-band and broadband Quasi-elliptical filtering responses with compact size and high selectivity. Moreover, the in-band radiation performance is almost unchanged. To analyze and guide the antenna design, the working mechanisms are presented. For demonstration, the proposed dual-band filtering antenna is implemented with Laser Direct Structuring (LDS). The overall size of the proposed dual-band filtenna is 0.16*0.09*0.04 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\lambda^{3}_{0}$</tex-math></inline-formula> operating with the fractional bandwidth of 10.2% and 13.6%, respectively. The in-band radiation efficiency is of -1.5 dB and -1 dB, respectively. The proposed filtering antenna features compact size, controllable frequency ratio and radiation nulls and high in-band radiation, rendering it suitable for Shark-Fin scenarios.