The beam switching cylindrical array, which is a unique system, has been designed and developed to cover 3600 in azimuth plane by generating 16 beams with specified elevation coverage. In this design, the concept of fast aperture selection (4 x 4) in microseconds from the total cylindrical array has been realised successfully to meet the requirement of point-to-multipoint communication. The components of the array, viz., radiating elements, powder dividers, switches, etc., are designed in printed circuit type, and hence, objectives of lightweight and ease of reproducibility are achieved. The lightweight of the array makes it accessible for easy mounting at a specified height for achieving longer communication range. Finally, a low-Ioss radome is incorporated to protect the array from environmental conditions. The various paramete"rs, viz., return loss, gain, and switched-beam radiation patterns were measured over a bandwidth of 300 MHz in L-band and typical measured results are presented in this paper.(ii) beam scanning is nearly continuous by using the phase shifters, which makes the antenna system complex arid costlier3. As the requirement of scanning is to generate a fixed beam in azimuth and also narrow beam in elevation planes, the cylin'drical array with 64 elements arranged in 4 rows and 16 columns (4 x 16) is considered, which provides moderate gain. A software for uniform distribution was developed to stud)\ .the effect of interelement spacing of cylindrical array, which reveals similar results4. Finally, the cylindrical array covering 20 per cent bandwidth in L-band has been designed and developed. The mutual coupfing effects were also studied experimentally5. The concept of fast selecting aperture in co-phasal condition for appropriate beam is implemented successfully. The antenna is housed in a low-Ioss, lightweight sandwich radome and is evaluated in azimuth and elevation planes in small steps of

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