Transmitter noise compensation - a signal processing technique for improving clutter suppression

A new signal processing technique, referred to as transmitter noise compensation (TNC), has been developed at the Naval Research Laboratory (NRL) to improve the capability of existing radars to suppress returns from strong clutter. This technique compensates for intra-pulse transmitter noise, as well as power supply instabilities, by capturing and processing an accurate replica of each transmitted pulse. Subsequently, through pulse-to-pulse comparisons, the measured transmit errors are used to derive a digital filter which compensates for the transmitter noise in the digital signal processor (DSP). This paper describes the transmitter noise compensation technique, its theory of operation, and the results from an experimental effort to demonstrate its feasibility. This experiment has confirmed the validity of the TNC concept and demonstrated an improvement of 15 dB or higher.