ACP Probe Measurement of On-Chip Strip Dipole Antennas at W Band

Two L- and T-shaped strip dipole on-chip antennas are designed and manufactured back-to-back in a single chip for 77 GHz operation. The antennas are measured for their reflection coefficients and radiation patterns at W band. It has been observed that measurements are highly influenced by the antenna placements and the ACP110-A-GSG-100 probe. To model the effect of air coplanar probe (ACP probe), a software calibration is performed similar to a network analyzer calibration, and then the antenna reflection coefficient is calculated using the modeled probe-fed antenna. The technique employs obtaining the probe ABCD matrix and then de-embedding from the simulation results to compare with measurements. The probe-fed simulated and measured reflection coefficients agree well for manufactured L and T antennas, which resonate at 86 and 81 GHz, respectively. There are resonance frequency shifts attributed to the ACP probe effect, and simulations show that antennas will operate at 79 GHz (L antenna) and 77 GHz (T antenna) in the absence of ACP probe. The results obtained are highly dependent on the ACP probe, antenna structure, and the environments/experiments on which the measurements are performed.