Radiation Pattern-Reconfigurable Leaky-Wave Antenna for Fixed-Frequency Beam Steering Based on Substrate-Integrated Waveguide

A novel reconfigurable leaky-wave antenna (LWA) with fixed-frequency beam-steering property is presented. The proposed antenna is designed on a substrate-integrated waveguide (SIW) whose effective width can be electronically changed. There are two rows of vias designed on each side of the SIW, and the vias in the outer rows are directly connected to the ground plane and top wall of the waveguide, but the vias in the inner rows are connected to the ground plane and top wall through p-i-n diodes that work as binary switches. By setting the states of the switches in a coding way, the effective width of the SIW can be changed numerically. Then, the propagation constant and the beam direction of the LWA can be altered accordingly. A prototype of the proposed antenna is fabricated and measured to verify the design procedures. The measured results show that the main beam direction can be steered from 46 degrees to 68 degrees in a step of 7 degrees at the operating frequency of 5.2 GHz, which confirms the effectiveness and practicability of this design.