A Ka-band power sharing multiple beam system proposal

Abstract

This paper present a new power sharing multiple beam mobile satellite system concept in Kaband. A wide allocated bandwidth and a large number of frequency reuse by multiple small spot beams allow to envisage a drastically new mobile satellite systems concept in Ka-band. At first, requirement for the beam size on the surface of the earth for voice signals transmission is considered. As system examples, geostationary systems with 3.5m and 10m(£ antenna are shown. If number of beam is hundreds to thousands, it is difficult to allocate a fixed high power transmitter for each beam. In order to cover varying traffic areas, this paper propose a new active array fed multiple beam antenna. The proposed active array consists of hundreds to thousands of similar elements with equal phase shift. Features and simulated performances of the proposed active array fed offset reflector antenna are presented. Since each beam commonly utilize all active array elements, power sharing among beams become possible. Traffic variation among beams will be accommodated in the system without loss of transmitting power efficiency.