Multi-Band Multi-Beam Higher-Order Space Harmonics-Enabled Leaky-Wave Antennas

This paper demonstrates the concept and feasibility of using higher-order space harmonics (HSH) in the development of one-dimensional periodic leaky wave antennas (1D-periodic LWAs). A methodology for analyzing the behavior of the propagation constant ($\beta_{\mathrm{n}}$) of HSH is presented by introducing two new concepts, namely safe zone area (SZA) and boundary region. They allow us to identify the number of beams and frequency bands to achieve multi-band and multi-beam antennas (MBMBAs). The proposed analysis methodology is experimentally validated by prototyping a dual-band multi-beam LWA (MBMB-L WA) based on substrate integrated waveguide (SIW) technology where the $\mathrm{n}\ \epsilon[-1, -2]$ space harmonics are utilized for achieving such a design. The measurement and simulation results show a good agreement with the theory and analysis of HSH.