A Printed Leaky-Wave Antenna Based on a Sinusoidally-Modulated Reactance Surface

A simple procedure for designing a sinusoidally-modulated reactance surface (SMRS) that radiates at an arbitrary off-broadside angle is outlined. The procedure allows for nearly independent control of the leakage and phase constants along the surface. Printing an array of metallic strips over a grounded dielectric substrate is discussed as a way to practically implement the theoretical SMRS. A method of mapping the gaps between metallic strips to a desired surface impedance is presented as an efficient alternative to mapping methods used in the past. A printed leaky-wave antenna with a sinusoidally-modulated surface reactance is designed using the procedure mentioned above. The TM-polarized antenna radiates at 30 degrees from broadside at 10 GHz, and exhibits an experimental gain of 18.4 dB. Theoretical, simulated, and experimental results are presented.