# Broadside Dual-channel Orthogonal-Polarization Radiation using a Double-Asymmetric Periodic Leaky-Wave Antenna

## TL;DR

This paper introduces a double asymmetric periodic leaky-wave antenna design that enables simultaneous broadside radiation of two orthogonal modes, enhancing polarization diversity for wireless communication applications.

## Contribution

It presents a novel double asymmetric unit cell design combining circularly polarized and coupled mode elements, demonstrating dual-mode broadside radiation through simulations and experiments.

## Key findings

- Double asymmetry enables orthogonal mode radiation
- Degree of transversal asymmetry controls cross-polarization discrimination
- Experimental validation confirms simulation results

## Abstract

The paper demonstrates that double unit-cell asymmetry in periodic leaky-wave antennas (P-LWAs), i.e. asymmetry with respect to both the longitudinal and transversal axes of the structure -- or longitudinal asymmetry (LA) and transversal asymmetry (TA) -- allows for the simultaneous broadside radiation of two orthogonal modes excited at the two ports of the antenna. This means that the antenna may simultaneously support two orthogonal channels, which represents an interesting polarization diversity characteristics for wireless communications. The double asymmetric (DA) unit cell combines a circularly polarized LA unit cell and a coupled mode TA unit cell, where the former provides equal radiation in the series and shunt modes while the latter separates these two modes in terms of their excitation ports. It is also shown that the degree of TA in the DA unit cell controls the cross-polarization discrimination level. The DA P-LWA concept is illustrated by two examples, a series-fed line-connected patch (SF-LCP) P-LWA and a series-fed capacitively-coupled patch (SF-CCP) P-LWA, via full-wave simulation and also experiment for the SF-LCP P-LWA case.