Leaky Wave Antenna Array using Complementary Dual-Stub Radiating Elements for Consistent Gain

This paper presents a 16 element Leaky Wave Antenna (LWA) array in the X-band for obtaining pencil beam radiation pattern with consistent gain. The design uses complementary dual-stub configuration in microstrip line technology to obtain linearly polarized beam in the propagation direction. The unit cell of the antenna is chosen with transversal and longitudinal asymmetry to achieve consistent gain while scanning through the broadside direction. First, a single LWA element is designed with 90% radiation efficiency. The main beam scans from −22° at 8 GHz to +41°at 12 GHz about the broadside direction with gain variation less than 0.6 dB. Next, the array is designed using this element and the individual elements are fed in phase using wideband multi-section Wilkinson power dividers. Measured peak gain of 28 dBi is obtained in the broadside direction at 9.25 GHz. The 3 dB beamwidth measured in the broadside direction in the two orthogonal planes are 3.2°and 7°, respectively.