Technology intercepts for the S-APAS architecture

The implementation of the S-APAS (Scalable Multifunction Radio Frequency - Active Phased Array System) concept requires the use of autonomous T/R modules connected to a common digital bus. The T/R modules have the functions of radiating energy in the radar space, collecting the relative returns and exchanging data and commands with the processing/control blocks. The technological aspects related to producing a T/R module, that is flexible and cheap enough to be used in different radar systems, at least within the same operating band, have been analyzed in previous papers. Further aspects derived from the S-APAS architectural concept have been considered here, in order to find the right intercepts with available technologies and with new technologies under development. In particular, the transmitter performance, the bus throughput and the performance of the data/ signal processing blocks are among the most critical items, to be analyzed carefully. This paper defines the dimensioning criteria for the proposed architecture in a number of cases related to different applications at different operating frequencies, defines the basic design principles and discusses the results, with respect to the above parameters, in order to find the technological constraints related to the physical implementation of the S-APAS architectural concept. The study is limited to applications with operating frequencies ranging from L band to X band, but the results can be easily extended to other frequencies of interest.