The design of cancellation unit against radiofrequency interference in life-detection radar

When the life-detection radar detects the human-life existence, echoes from stationary barriers are generally so strong that make the post-amplifier saturated and submerge the useful life signal. In this paper, a method of interference suppression is discussed. To restrain strong interferences, a reference signal deriving from emission signal is used to cancel the clutters. This paper designs a cancellation system using Microcontroller Unit and the amplitude and phase modulation unit to produce the reference signal. The searching algorithm is proposed to find out the best digital values that respectively control the amplitude and phase of reference signal. To improve the efficiency of algorithm in the searching process, searching procedures of phase and amplitude are discussed. Simulation results are shown in a three-dimensional diagram.