Real time digital signal strength tracking for RF source location

A Direction Finding (DF) system is implemented and measured for the 915MHz ISM band. This system covers frequencies up to 1.5GHz with an instantaneous bandwidth of 1.5GHz. It is capable of electronically steering multiple scan beams with 0.7° resolution and scanning speeds 5MHz via digital signal synthesis. A computationally efficient implementation of the digital beamforming is demonstrated that enables direct implementation in an FPGA or ASIC. The architecture also provides digital calibration of distance versus signal strength, system impairments such as channel gain/phase mismatch, and ambient RF noise power.