The need for low cost and low size radiometers have encouraged many to look at the implementation of radiometers using MMICs. Compared to their waveguide counterparts, radiometers implemented with MMICs significantly reduce the size and weight of the radiometer, while still maintaining satisfactory electrical performance at millimeter wave frequencies. Utilizing MMICs can also help in significantly lowering the noise temperature of the radiometer, specifically, metamorphic high electron-mobility transistors (mHEMT) have demonstrated very low noise, high gain performance and comparably low cost. This thesis is focused on designing a combined switch and low noise amplifier IC at 36.5 GHz that lowers the radiometer noise temperature while allowing for an accurate calibration. The measured gain from straight and 90 degree input of the switch-LNA, at 36.5 GHz, was 6.6 dB and 7.1 dB, respectively. Likewise, the noise figure of the MMIC was 3.8 dB and 3.3 dB, respectively. The mHEMT implemented SPDT switch has a measured insertion loss, at 36.5 GHz, of 1.3 dB and 0.88 dB with isolation of 25 dB and 36 dB, respectively. The calculated temperature sensitivity based on measured temperature variations was 0.273 K at 36 GHz.

High frequency solid-state switches are critical elements in communication systems, radio frequency (RF) systems and instrumentation. Key parameters to an RF switch include insertion loss while on and off-state isolation. Power handling and linearity are important to consider for a cost-effective construction. This becomes a design challenge into K-band frequencies as components required need to be small, dielectric losses and transmission lines need to be physically matched for proper isolative and through states. This thesis presents a novel single pole eight throw (SP8T) hybrid design composed of commercially available surface mount technology solutions to achieve high isolation and low insertion loss from 2-20GHz. A range of PIN diode solutions were surveyed against key design requirements for the SP8T hybrid switch. There were no commercially available solutions for a SP8T switch using surface mount components. A SP2T switch is combined with two SP4T to make the hybrid model. A wide range of RF switch topologies were simulated and designed into a printed circuit board panel that includes 15 test structures. This board is fabricated on a low loss dielectric material with a 4-layer stack that is operational up to 20 GHz and beyond. An onboard calibration structure including STOL standards are tested through a vector network analyzer to determine losses and reflection. Each switch design is on its own board to better determine the performance of the SP8T hybrid. High frequency coplanar waveguide to 2.4mm coaxial connectors are used to evaluate each board. This design is characterized against individual MMIC and PIN diode boards through switched states in decibels (dB). Second harmonic content is also measured at a target frequency at 2.4GHz for all configurations to determine the magnitude of undesirable spectral content with input power no greater than 10dBm. Results display acceptable loss in the lower half of the frequency band and narrow resonance nearer to 20 GHz due to board loss and reflections. This design has been successful in its design and operation at broadband RF frequencies. Performance characteristics are given in the summary section. Details of the design process and measurement methodology are given in the body of this thesis.