Millimeter-wave radar techniques

Advantages of a use of millimeter waves in place of microwaves are related to a reduced antenna diameter for the same antenna gain, an enhanced angular resolution, improved resolution in distance measurements, a favorable Doppler frequency range, and a larger radar cross section. A large-scale utilization of the millimeter wavelength region has now become economically feasible in connection with advances related to modern semiconductor technology. Gunn elements, IMPATT diodes, and Schottky barrier layer mixer diodes for frequency ranges up to 100 GHz are commercially available. Current millimeter-wave radar devices employ as much as possible semiconductor components. A description is presented of the various possibilities for an application of the considered technology, taking into account basic radar principles and three different types of radar sensors. Crucial aspects of future developments are concerned with semiconductor reliability and the design of integration procedures for a reduction of costs.