Beam-Splitting Condition in a Broadside Symmetric Leaky-Wave Antenna of Finite Length

Abstract

In this letter, the influence of the truncation effects onthe beam-splitting property of a broadside symmetric leaky-waveantenna (LWA) is presented. It will be shown that for finite lengthLWAs, the maximum broadside beam exists at higher phase constantvalues than suggested by infinite LWA analysis. The accuratebeam-splitting conditions are obtained using a computer search algorithmand are reported for a range of practical LWAlengths. Thebehavior of the aperture distributions at the split conditions is thendiscussed. To illustrate the application of the result, the theoreticalbeam-splitting condition plot is used to identify the beam-splittingpoint of a microstrip based LWA design. Finally, other design implicationsof the findings are discussed.