Design and Optimization of Metallic Cavity Packaging for Millimeter-Wave RF Chips

In millimeter-wave (mmWave) front-end systems, low insertion loss and low return loss chip packaging technologies significantly impact overall system performance. This paper presents a metallic cavity packaging technique for mmWave RF chips, including critical components such as waveguide-to-microstrip transition structures, bare-die gold wire bonding, and impedance matching methodologies. A V-band design example is demonstrated to validate the proposed approach. Simulation results show that the optimized packaging structure achieves a transmission coefficient better than 0.5 dB and a return loss exceeding 12 dB across the 45 GHz-80 GHz frequency range, meeting practical engineering requirements.