A critical review of angular resolution vs. beamwidth in antenna systems

The angular resolution of a given antenna system is usually believed to be limited by the beamwidth. Therefore, many antenna design efforts are aimed at improving angular resolution by means of more directive beams, normally involving large size (or aperture) antennas. However, the antenna beamwidth limits the bandwidth of the system (the maximum detectable frequency), but not the maximum achievable angular resolution. This concept is more related to the sampling intervals used in the data capturing process. The signal received by an antenna system can be modeled as a convolution of the observed scene and the antenna beam, and it would thus be possible to apply inverse filtering methods. In that event, we can reduce considerably the sampling intervals for data capturing and subsequently perform an inverse filter, obtaining the angular resolution stablished by the sampling rate. This concept involves the chance of using a lower angular resolution antenna (much simpler and smaller) to obtain similar results in relation to angular resolution. In this article, we compare the simulation of a data capturing process of a high angular resolution antenna and a lower resolution one (2 times less directive and smaller), which obtains satisfying results thanks to post-processing techniques based on previous theories.