Enhanced Receiver Architecture For Leakage Reduction in Wideband EW Transceivers With Overlapping RF And IF

EW transceivers with high input dynamic range, wide bandwidth and overlapping RF & IF frequency bands for simultaneous detection and characterization of incoming signals, are susceptible to RF & LO leakage to IF resulting in erroneous identification of leakage and spurs as threat signals using conventional approaches. This paper presents an enhanced receiver architecture which has been fabricated and tested successfully for RF section of Wideband digital channelized transceiver for precise identification of threat signals by translating the entire input frequency band to X-Band and down-converting to overlapping IF. This eliminates direct leakage problem along with relaxed filter rejection & Mixer isolation requirements for image and spurious rejection and provides clean down-converted signals in multiple input scenario for Nyquist sampling at Low IF. The system has been tested successfully with spurs, RF & LO leakage levels of −60dBm for closely spaced dual input pulsed signals in −10 to −50dBm dynamic range. Enhanced architecture, test results and comparison of the results with heterodyne architecture have been presented.