Polarization and pattern agile planar periodic 2-D bull’s-eye leaky wave antenna with open-stopband suppression

A radially periodic 2-D leaky wave antenna (LWA) with high gain at broadside, reduced sidelobes, and suppressed open-stopband (OSB) is presented in this communication. The antenna is low profile and is defined by a printed, double microstrip bull’s-eye aperture. To support polarization and pattern agility, as well as applications in full-duplex systems and dual-polarization scenarios, the antenna is fed with a compact multislot array at the center of LWA, enabled by substrate integrated waveguide (SIW) technology. When considering differential excitation, the simulations and measurements demonstrate a maximum realized gain of more than 17 dBi at broadside at about 18.4 GHz. Furthermore, due to the suppression of the OSB, persistent broadside radiation is supported from 18 to 19 GHz, along with continuous and sustained directive radiation when the main beam scans through broadside, which is in agreement with leaky-wave (LW) theory. Applications include vehicle antennas and V2X communication systems, satellite connectivity, polarization and pattern diversity scenarios, radar and monopulse systems, as well as 5G/6G wireless communications.