Finite measurement distance effects on the broadside symmetric leaky wave antenna

In this paper, the effects of finite measurement distance on the measured radiation pattern of a the symmetric broadside LWA was investigated. Specifically, the broadside beam behaviors near the splitting condition were examined. It was found that while the FF pattern is unaffected, the finite distance pattern varies depending on the sign of beta^. Furthermore, near the splitting condition, an error of 1 dB in the broadside directivity can be expected for the rule of thumb measurement distance of 2L²/lambda_o.