Under-decimated 3D FIR space-time cone filters using DFT polyphase filter banks for attenuation of radio frequency interference

It is shown that, by employing 2D FIR spatial filters and under-decimation, the computational time of 3D space-time polyphase cone filter banks may be significantly reduced. The resultant input-output 3D transfer function is almost alias-free and, further it is shown that the proposed cone filters can be used to effectively attenuate such stopband signals as radio frequency interference in radio astronomy applications.