Design of Compact Wideband Dual-Band Pattern- and Polarization Diversity In-Vehicle Antenna

A dual-band pattern- and polarization-diversity antenna for vehicle applications is proposed. The presented antenna is composed of three parts: chessboard patches, near-field resonance parasitic (NFRP) monopole array and L-shaped driven dipole. The chessboard patches are excited by L-shaped driven dipole to realize broadband broadside right-handed circular polarization (RHCP) in the lower band. The monopole array, acting as an NFRP element, is excited by chessboard patches to achieve bidirectional end-fire radiation in the upper band. The presented antenna is characterized by compact size (0.43 lambda(0)*0.43 lambda(0)) and wide bandwidth (lower band:18.4%, upper band:3.4%). Simulated results demonstrate that the presented antenna possesses broadside RHCP and bidirectional beam in 3.79-4.56GHz and 5.77-5.97GHz, respectively, which is suitable for vehicle applications.