Postwall waveguide slot array with cosecant radiation pattern and null filling for base station antennas in local multidistributed systems

Abstract

The authors propose to use planar antennas of waveguide slots with the simple structure of postwall waveguide for base station antennas in Local Multipoint Distribution Systems (LMDS). The array has a cosecant radiation pattern with null filling in the vertical plane for uniform illumination in a sector area. The slots are paired as an element to achieve traveling wave excitation because the phase, as well as the amplitude, has to be controlled for null filling in a cosecant pattern. It is the first time to design an array of reflection‐canceling slot pairs to get a tapered distribution both in amplitude and phase. This paper extends the designability of the reflection‐canceling slot arrays. A 16‐element array is designed at 25–26 GHz band. The model array has a cosecant pattern with 3‐dB deviations and a peak gain of 17.1 dBi in measurements.