Beamforming with Uniform-Circular-Array and Ultrawideband-Throb Signal

In this paper, the principle of beamforming using uniform circular array (UCA) antenna and ultrawideband (UWB)-throb signal is presented. The space-time resolution function of a UWB-throb signal received by a UCA antenna is derived and used to obtain the average-power beam pattern of the UCA. The elevation power pattern (EPP) and the azimuth power pattern (APP) for a UWB-throb signal and linear-frequency-modulated (LFM) signal, also referred to as chirp signal, received by a UCA are generated and compared. The EPP as well as the APP of the UWB-throb signal yield better angular resolution capability and have lower sidelobe levels than of the EPP and the APP of the LFM-chirp signal. It is shown that beam steering in the elevation plane of the UCA widens the beamwidth and influences the sidelobe structure of the power pattern, but not its general shape, while beam steering in the azimuth plane of the UCA is more robust and causes no deformation or widening of the power beampattern.