The reconfigurability is widely regarded as a viable option for meeting the changing requirements of modern radio links. Telecommunciaton satellites may benefit from antenna reconfirgurability, in particular the coverage areas of broadcasting satellites may be reconfigured by making use of reflector-type antennas using multiple feeds . Moreover, antenna reconfigurability can be used for switching between different transmission modes in terms of the received/ transmitted power, allowing the antenna gain to be dynamically adjusted to the changing channel requirements. For example,  describes a strategy for dynamically tuning the antenna gain for counteracting the extra attenuation occurrin gin case of cloud coverage or rain precipation over the illuminated areas.
In the present contribution we propse a strategy for reconfiguring non-uniform array-antennas. The proposed approach is based on the thinning of a uniform array achieved by switching on and off the transmit/ receive modules (TRMs) feeding the individual radiators. By strating from a fully populated, uniform configuration, different thinned arrays can be obtained by electronically switching off some of the individual TRMs. By changing the thinning ratewe are able to compensate for the gain-loss due to the steering of the antenna beam while keeping the peak sidelobes level (PSLL) under control.
In order to assess the scanning performance of the thinned arrays a non-uniform array-antenna designed by means of a Genetic Algorithm (GA) approach  is compared with an array obtained by thinning down a uniform, lambda/2 spaced configuration (with lambda denoting the wavelength at the maximum operational frequency). The number of elements in the two arrays is 30 and 36, respectively, and their total length is approximately the same. The thinned array turns out to perform better than the GA array as the main beam is steered away from the boresight direction, providing, at the same time, a certain degree of reconfigurability.
|Publisher||European space research and technology centre (ESTEC)|
|Conference||29th ESA antenna workshop on multiple beams and reconfigurable antennas - innovations and challenges|
|Period||18/04/07 → 20/04/07|
- conference contrib. refereed
- Conf.proc. > 3 pag