Wideband Beam-Switched Bow-Tie Antenna With Inductive Reflector

Abstract

A wideband pattern reconfigurable bow-tie antenna on an inductive reflector is presented. The antenna consists of three bow-tie structures printed on an FR-4 substrate and controlled by six p-i-n diodes. The excited bow-tie at each operating state acts as the driven antenna, while the other bow ties act as the parasitic elements. To achieve low profile and high gain with directional radiation, a 5 × 5 metallic mesh-grid structure is designed as an inductive reflecting surface. It is located at a distance of $0.08{\lambda _0}$ (where ${\lambda _0}$ is the wavelength at the lower operation frequency) from the radiator. The antenna is able to steer the radiation pattern at the angles −25°, 0°, and +25° in the azimuth plane. Moreover, it is capable of electronically switching polarization along the diagonal section of the antenna's surface. It has a compact size of $0.6{\lambda _0} \times 0.6{\lambda _0} \times 0.08{\lambda _0}$ , measured fractional bandwidth of 37% at 0.8–1.16 GHz for tilted states, peak measured gain of 9 dBi, and maximum measured front-to-back ratio of 12 dB with ±1 dBi gain variations and ±3° peak pattern's direction variations across the whole bandwidth in all operational states.