Simple MIMO imaging system based on phase compensation and hardware calibration

This paper presents a simple Multiple Input Multiple Output (MIMO) imaging system based on phase compensation and hardware calibration. The antenna array of radar system composed of 6 transmit elements and 8 receive elements synthesizing a fully populated 69 cm long linear array is about 1 meter long. With electronic switch matrices controlling the antenna pairs, only one antenna pair works once a time in order to eliminate the antenna coupling. According to the Bi-static Theory, the antenna array is able to synthesize 24 effective mono-static elements which require 24 bi-static pairs with conventional method, providing the same capability with less than two-thirds antennas. However, a phase center error dues to the synthesizing approximation needs to be eliminated while we introduce a new software method to compensate the phase error. Additionally, we introduce a calibration method to eliminate the phase error caused by microwave cables, switched-antenna-array matrixes and so on. The algorithm for 2d imaging named Range Migration algorithm is discussed in the paper. Simulation and measurement of two metal square blocks will be presented in the end.