An integrated millimeter-wave monopulse radar receiver with polarimetric capabilities

This thesis presents the development of integrated antenna and circuit technology for a high-performance, miniature 94 GHz monopulse radar receiver. The specific intent of this receiver is as the front-end for shipborne point defense applications (a short-range, small-target, high-multipath and high-clutter mission), but the technology is applicable to millimeter-wave automotive radar and communications systems as well. Among the design objectives are a small aperture, wide IF bandwidth (for range resolution), low noise figure, sub-milliradian angular accuracy, and compatibility with monolithic millimeter-wave integrated circuit (MMIC) processing. A further objective is the potential for exploiting polarization diversity to improve discrimination between a radar target and disturbances such as clutter, chaff, and jamming.; The receiver is based on a 2 x 2 array of coplanar-waveguide-fed slot-ring antennas placed on an extended hemispherical dielectric lens; the slot-ring antennas are compact and offer the potential for polarimetric operation. The dielectric lens eliminates losses to substrate modes allowing the millimeter-wave electronics to be fabricated on standard-thickness wafers. A thorough characterization of single- and dual-polarized slot-ring antennas is presented including method-of-moments simulations and millimeter-wave measurements, the dual-polarized antenna demonstrates a port-to-port isolation of better than {dollar}-{dollar}25 dB over a 5% bandwidth. This is followed by an investigation of a high-performance, uniplanar W-band subharmonic mixer. Subharmonic mixing is utilized due to the relative ease of distributing the lower frequency LO on chip, and the inherent RF/LO isolation. The measured minimum single sideband conversion loss is 7.0 dB at a 94 GHz RF and a 2-4 GHz IF, and represents state-of-the-art performance for a planar subharmonic mixer at W-band. The CPW-fed slot-ring antennas are then integrated with the uniplanar subharmonic mixers to realize individual receiver channels. Novel on-wafer antenna and receiver measurement techniques are also presented.; Finally, the integrated monopulse receiver is presented. Excellent monopulse patterns are achieved, with better than 45 dB measured difference pattern nulls using IF monopulse processing. This translates to sub-milliradian angular accuracy for a 24 mm aperture. Better than 25 dB nulls are possible over a 600 MHz bandwidth. The dissertation concludes with a discussion of future research directions building on this work. Included in the appendices are several complementary millimeter-wave antenna and circuit technologies.