Miniaturisation of conventional radio-link reflector antennas by using of active arrays

Using of active array antennas has been shown as a suitable technique to improve the figure of merit (G/T) of a radio-link, increase the effective gain or make a better distribution of the power what can reduce the number of amplifiers used in the feeding network [1]¿[2]. As one of the characteristics of active antennas is that it can improve the effective gain, a trade-off between the increase of effective gain and the reduction of antenna size can be done. The effect of including active elements to increase the effective gain while maintaining the radio-link gain implies a reduction in the antenna size. The paper presents the reduction that can be achieved in the antenna size by using of an active array. A study of the level of active element integration (patch level or subarray level) has been done to obtain the optimum situation between the size reduction factor and the power associated to any of the amplifiers in the active array.