A TM11 High-Order Mode Leaky Wave Antenna

A novel leaky-wave antenna (LWA), which operates at the $TM_{11}$ high-order mode, is proposed. This LWA achieves a 4.6 times higher gain than the traditional TE10-based LWAs. An analytical formulation is derived, which shows that a $TM_{11}$ -based LWA couples more energy to free space through an appropriately designed slot than traditional TE10-based LWAs. Simulations are used to compare the performance of our proposed $TM_{11}$ -based LWA with a similar LWA that operates at its fundamental TE10 mode. Specifically, it is shown that our $TM_{11}$ high-order mode LWA achieves 6.67 dB higher gain than a TE10-mode LWA that operates at the same frequency. Also, a $TM_{11}$ -mode LWA is designed to mitigate the open-stopband (OSB) problem. This design achieves a fan beam with a maximum gain of 15.4 dBi and a scanning elevation range of 18° (through the broadside direction) in a bandwidth of 2 GHz. Prototypes of our LWA designs are manufactured using a cost-effective additive manufacturing method (i.e., selective laser melting), and their performance is measured. The measurements exhibit good agreement with simulations, thereby validating the proposed designs.