Radar: Reflections and speculations

This paper discusses three diverse topics in radar that have little relationship to one another, other than they represent what might be interesting for further exploration. These topics are: (1) a suggested origin for microwave sea echo (something not currently understood), (2) a different type of phased array radar architecture based on digital beamforming that can overcome a serious weakness of current multifunction phased array systems, and (3) recognition that the electromagnetic spectrum available for radar might be considerably reduced by the insistent demands of non-radar users of the spectrum. None of these can be said to be completed studies at present.