Design of a compact printed lowpass filtering antenna with wideband harmonic suppression for automotive communication

This article presents a printed planar lowpass filtering monopole antenna with wide stopband for automotive communications. This monopole radiator exhibits hybrid geometry and is constructed using a circular slot and corner edged slot. The fundamental radiator's ground plane is defected to enhance the VSWR bandwidth and four rectangular patches with two open‐circuit stubs is being used to construct a lowpass filter with wide stopband. The filtering characteristics are further improved by incorporating circular complementary split‐ring resonator (CCSRR) on the ground plane. The proposed lowpass filtering antenna is obtained by integrating the lowpass filter with a super wideband (SWB) monopole antenna and experimentally validated with the measured reflection coefficient as 4.45 dBi. Further, the prototype filtering antenna bandwidth and radiation characteristics are analyzed in housing effects. The filtering antenna can be conveniently printed along with the existing printed circuit board or it can be located inside the shark fin housing thereby eliminating the need for a dedicated location in vehicular communications.