The evolution of broadband communication satellites shows a clear trend towards antenna beam-forming and antenna beam-switching systems with efficient multiple access schemes at wide bandwidths, which to be economically viable communication price should be as low as possible.
In such applications, the most demanding antenna concept is the Direct Radiating Array (DRA) since its use allows a flexible power allocation between beams and may afford failures in their active chains without relevant pattern degradation.
The antenna control can be done mainly in three ways: with microwave, digital or optical processors. Microwave processing systems are limited to the mass and volume of microwave devices and guides and the bandwidth of digital processors is limited due to power consumption and complexity constraints. However,the photonic technology is an enabling technology that can improve the antenna feeding network performance overcoming the limitations of the traditional technology in the more demanding scenarios. Moreover, integrated optics technology can play a crucial role as an alternative technology for implementing beam-forming structures for satellite applications thanks to the well known advantages of this technology such as electro-magnetic interference immunity, low consumption, low volume and weight, huge electrical bandwidth, low-attenuation remote delivery capability (due to the optical fibre) and the robustness and precision that exhibit the integrated optics, especially in the case of Silicon-on-Insulator, due to the compactness and its compatibility with the standard CMOS technology.