The superconductor digital receiver technology allows direct digitization of RF signals and digital processing of the digitized RF signals up to very high RF frequencies. Fig.1 illustrates a block diagram of a superconducting digital RF receiver. It consists of an analogue front-end and a superconductor analogue to digital (ADC) converter. The analog front-end includes a channelizer, and the power limiters. The ADC is realized using rapid single-flux quantum (RSFQ) logic. High performance RF bandpass and band-reject filters are employed in the front-end of such digital receivers to facilitate efficient utilization of the frequency spectrum and for suppression of interfering signals. While superconductor ADCs are capable of digitizing very wide band RF signal, the current fabrication technology of RSFQ logic, makes it more feasible and more efficient to implement superconductor ADCs with a bandwidth of 20-30 GHz. Wider band signals can be realized with the use of several ADCs and a wide-band millimeter-wave channelizer as shown in Fig 1. The ability to integrate monolithically high-Q filters up to millimeter-wave frequencies with ADCs on a single chip will enhance the RF performance of the digital receiver and will reduce its overall size. Moreover the ability of realizing reconfigurable front-end components that are amenable with Superconducting technology will pave the way of realizing a multiband interference-free receiver with a superior performance. The talk will address the research efforts at the University of Waterloo for the development of:
-          Niobium-based bandpass filters covering the frequency range from 300 MHz up to 100 GHz.
-          Wideband millimeter-wave channelizers for integration with digital receivers.
-          Niobium-based MEMS switches capable of operating at 4K.
-          Tunable niobium-based band reject filters.
-          Filter-based power limiters capable of protecting superconductor digital receivers.

Fig. 1 A block diagram of a superconductor digital receiver.

Keywords: Superconductor Niobium  Filters, Tunable superconductor filters , Superconductor ADC  , Power Limiters