Author_Institution :
Associated Electrical Industries Ltd., Advanced Development Laboratories 2, Telecommunications Group, London, UK
Abstract :
A new class of time-varying lowpass and highpass filters is described in which the stopband attenuation is obtained by outphasing in a quadrature-modulation arrangement, the undesired associated frequency translation or inversion being cancelled by a suitably chosen second step of quadrature demodulation or both; bandpass and bandstop filters can be obtained as combinations of lowpass and highpass filters.
