A Dual-Polarized High-Gain Endfire Antenna With Enhanced Bandwidth by Employing Symmetric Meander-Line Radiators

Abstract

In this letter, a dual-polarized high-gain endfire antenna is proposed using symmetric meander-line radiators with differential feeding. The symmetric radiator, comparing to typical single-arm asymmetric meander-line design, provides a much flatter phase constant closely matching the Hansen–Woodyard condition and ensures a higher gain and broader bandwidth within a compact length, which is the key contribution of this design. A wideband microstrip-to-slotline transition is adopted to realize differential excitation and improved impedance matching. Measured results exhibit endfire gains of 12.3 dBi/12.5 dBi, impedance bandwidths of 9.1%/8.9%, and port isolation better than 20.9 dB. Compared with the nonsymmetric meander-line antenna, the proposed design achieves 2.3 dB higher gain and nearly double bandwidth. The proposed antenna would be suitable for target detection and wireless communication systems.