Direct Chip-to-Waveguide Transition Realized With Wire Bonding for 140–220 GHz G-Band

This work presents a method to realize a direct chip-to-waveguide transition by means of commercial wire-bonding tools. A straight E-field probe is formed by a freely suspended bondwire and mounted to a standard RF pad on-chip. In contrast to conventional approaches, no additional dedicated substrate or large integrated radiating structure are necessary. A preliminary analysis is performed to illustrate the basic feasibility and a WR-05 prototype module, with dedicated test chip, is designed and optimized for a frequency range of 140-220 GHz (G-Band). The measured return loss of a back-to-back configuration is above 10 dB, while the deembedded absolute loss of a single transition is between 0.4 and 1 dB, both within the complete waveguide bandwidth of 80 GHz. The demonstrated performance is very well suited to ultrawideband communication systems or general-purpose mm-wave components.