Multi-Beam Reflector Antenna System Combining Beam Hopping and Size Reduction of Effectively Used Spots

This paper describes a concept combining beam hopping and size reduction of effectively used spots that can be implemented on multiple-beam antennas to improve their performance, namely the carrier-to-interference ratio, the minimum directivity, and the roll-off. The expected impact on antenna RF performance is demonstrated based on simplified models. A more-realistic focal-array-fed reflector antenna is also presented, based on a cell-reuse scheme of 12 reduced to four (one-third of the coverage receiving all the available bandwidth according to a cell-reuse scheme of four at a given instant), with performance in line with the simplified model. This specific design enabled improving the antenna's performance without drastically increasing its complexity: the minimum directivity and C/I were respectively 1.67 dB and 3.65 dB higher when compared to a standard antenna implementation with a cell-reuse scheme of four.