Beamwidth Evaluation of Finite-Length 1- D Bidirectional Leaky-Wave Antennas

In this work we analyze the beamwidth properties of one-dimensional (1-D) bidirectional leaky-wave antennas (LWAs) when the antenna is pointing close to broadside. Existing formulas neglect the effect of the aperture truncation, which affects the exact value of the beamwidth for practical realizations of 1-D LWAs. Using a rigorous theoretical framework, we find a transcendental beamwidth equation, whose numerical solution furnishes the exact value of the beamwidth for finite-length 1-D bidirectional LWAs. Numerical results confirm that the aperture truncation considerably affects the beamwidth properties, especially for limited efficiencies.