Multistatic Cw-Dopplerradar with Lateral Resolution for Short-Range-Applications at 35 GHz

Lateral resolution without scanning the antenna is achieved by a new method, which uses several homodyne receivers positionned along a linear aperture in order to evaluate the incident angles of the incoming wavefronts. The sampled values of the field distribution along the aperture are submitted to a Fourier transform, giving the directions of incidence. As this method is used for short range applications, the reduction of the sensitivity imposed by the homodyne principle can be tolerated, avoiding expensive IF circuitry. Considering moving objects, the changes of the incident field distribution is well described by the doppler effect. This means, that only low frequency data have to be processed and the evaluation of the data can be done on-line by a desk-top calculator. In a laboratory set-up the performance of the system was evaluated, giving the desired resolution, and in the absence of other scatterers an angular measurement accuracy of ± 0.026°.