Numerical modeling of V-shaped linearly tapered slot antennas

Efficiency, bandwidth, light weight and geometric simplicity are among the most crucial requirements for antennas designed for some specific applications, such as airborne radars and communication systems. One of the most desirable candidates catering for these demands is the tapered slot antenna (TSA), which belongs to a group of endfire traveling wave antennas and consists of a tapered slot etched onto a thin film of metal with or without substrate on one side of the film. The most attractive features of the TSAs in contrast to other kinds of planar antennas are that it can work over a large frequency bandwidth and produce a symmetric endfire beam with appreciable gain and low sidelobes. This paper reports a study of a previously proposed V-shaped linearly tapered slot antenna (V-LTSA) by employing the spectral domain method. The method is based on the exact Green´s function and the moment method procedure in the spectral domain to obtain the reflection coefficient and the unknown electric currents on the antennas. The currents are approximated by subsectional basis functions in both transverse and propagation directions. Several examples of the V-LTSA have been examined using the piecewise sinusoidal and roof-top basis functions, respectively. Results are presented for reflection coefficients, equivalent circuit parameters and current distributions, some of which are validated by measured results and those obtained from the FDTD.