Packaging of a state-of-the-art v-band active cold load and RF switch

Sammanfattning

Microwave radiometers must be regularly calibrated to maintain high measurementaccuracy. Conventional calibration systems often use cold sky and onboard referenceviews. These different views are typically selected using a rotating mirror. AnActive Cold Load (ACL) can provide an electronically controlled cold reference directlyin the receiver chain, while a Radio Frequency (RF) switch routes the receiverbetween the measurement and calibration reference paths.This thesis presents the packaging and integration of two V-band Silicon-Germanium(SiGe) Monolithic Microwave Integrated Circuits (MMICs), an ACL and an RFswitch. The thesis includes the design of a WR-15 waveguide-to-planar transition,bondwire interconnects between MMIC and transition, split-block design and biasingboards. Specifically an E-plane probe on alumina was developed and designedfor the SiGe MMIC interface using a Coplanar Waveguide with Ground (CPWG)section and a multi-stage impedance transformer optimized in ANSYS High FrequencyStructure Simulator (HFSS).The transition achieved a simulated return loss of S11 < −26.9 dB and S21 >−0.3 dB across the targeted frequency band 50 − 60 GHz. In addition, a backto-back structure showed S11 < −17.8 dB and S21 > −0.6 dB. Furthermore, asensitivity analysis was performed, demonstrating that the design remained belowS11 < −20 dB for all investigated variations. The design was evaluated through fullwaveelectromagnetic (EM) simulations, while the planned scattering parameter andnoise temperature measurement procedures are described for future characterization.The simulation results suggest that the proposed packaging design is suitable torealize compact V-band ACL and RF switch modules for radiometer calibration.