Patent ID: 7825858

Claim:
A system for estimating bearing of a target based on RF signals received by an array of antenna elements, the system comprising: first and second analog lines for receiving analog signals corresponding to first and second antenna elements within the antenna element array; an A/D converter module for converting each of the analog signals to digital data and for outputting separate digital data streams corresponding to each of the first and second antenna elements; a phase shift module for shifting each of the first and second data streams by a predetermined amount of time to form first and second phase shifted data streams, a phase detector module for calculating in-phase (I) data based on the first and second data streams and for calculating quadrature (Q) data based on the first and second data streams and the first and second phase shifted data streams; and a surveillance module for determining a bearing of the target based on the I and Q data, wherein the phase detector module calculates a mixed in-phase data stream by multiplying the first and second data streams and includes a delay module that delays the mixed in-phase data stream by a fixed time delay to output the delayed mixed in-phase data stream.