Accurate formulas for the beamwidth of 1-D bidirectional leaky-wave antennas

In this work, we accurately evaluate the beamwidth of one-dimensional (1-D) bidirectional leaky-wave antennas (LWAs) radiating at broadside. Indeed, existing formulas neglect the effect of the aperture truncation, which affects the exact value of the beamwidth for practical realizations of 1-D LWAs. By exploiting a well-established theoretical framework, we find an approximate, but still accurate analytical formula for evaluating the beamwidth of finite-length 1-D bidirectional LWAs radiating at broadside. The comparison with numerical results confirm the accuracy of the proposed formula, whereas the comparison with previous formulas confirm its relevance for accurate LWA design.