Extension of transmission-line model for longitudinal-slot dielectric-filled waveguide

This Letter presents a well-suited model for the analysis of longitudinal-slot dielectric-filled waveguide antennas by extending the transmission-line model used for printed slot antennas. The found slot admittance is calculated on the waveguide plane thanks to a transformation ratio that corresponds to the current discontinuity, taking into account the permittivity of the antenna. The results obtained with the use of this methods are first compared to a commercial software based on the FDTD method, for two dielectrics, with different slot offsets, in the millimeter-wave band. Second, the method is compared with a measurement. (C) 2002 Wiley Periodicals, Inc.