Electronics & Radar Development Establishment. Bangalore-560 093 and

II The paper ckals with the cksign and ckvelopment of a dual polarised corrugated conical horn employed as a feed for parabolic nrflector antennas used in very small aperture terminal applications. The V SA T antenna feed is designed. fabricatf1d and tested toloperate over a band from 3.7 GHz to 6.5 GHz with good pattern sy~etry.lo ~ sick lobes and low cross-polarisation. Networks using VSATs provide two-way transmission links using antennas with diameters up to 2'.4 m: The antenna ~Iays the role df RF interface in the earth/space link. It provides di~ectivity, isolation co~erage and connectivity with prime concern on mass, size, cost and its technical and economic viability. In Isuch small aperture antennas, offset feed reflectors are employed to achieve low far off side lobes. These antennas have high efficiency, low ~ide lobe levels ~nd low noise temperatures. Domestic satellite communication systems have an uplink fr{)m the earth station to the satellite and a downlink from the satellite to the earth station and are based mainly on 6/4 GHz, 14/11 GHz and 14/12 GHz bands. The design and development of feed systems for multifrequency bands is one of the most important tasks in the antenna design. Since most of the feeds for these antennas are beingI imported, the total cost of the ant,enna can be reduced..-ffl--l'liv<.ly Ily <1...~igJliJlg 111i ~ ~IIII ~y~ICIII illuigclIollNly without compromising on electrica,1 performances