Analog implementation of high resolution DFT in RF domain, utilizing a special multilayer realization of Rotman lens

A passive DFT processor using a special realization of a Rotman lens is proposed which provides higher resolution with less complexity in compare to the traditional Butler matrices implementation which their complexity increases exponentially with resolution. The design is extended to 2X point by adding another dimension in form of stacked configuration which is easily available in multilayer PCBs. By offsetting the center frequency of the serial-to-parallel converter from that of the lens, the bandwidth of the processor was increased from 320 MHz to 1 GHz maintaining error at the same level (~4%). This is more than 3X bandwidth enhancement, making this design suitable for processing wide band time domain signals.