High-gain low-cost broadband 60 GHz differential integrated patch array antennas with wire-bonding packaging and on-board compensation network

Two high-gain broadband 60 GHz integrated planar patch array antennas, without and with air cavity, are designed and implemented on Rogers 5880 substrate. The differential antenna structure is used to improve the signal integrity at millimetre-wave frequencies. The antennas are co-designed with bonding wires of which the parasitic effect is compensated using a passive network. The proposed antennas have the advantages of symmetrical radiation pattern, wide bandwidth and low insertion loss. In the measurement, a differential transmission line based de-embedding structure is developed on silicon, mimicking the real chip packaging environment and providing reliable terminations for antennas. The measured fractional bandwidths (|S₁₁| < -10 dB) are 13.8 and 26.2%, respectively, for the two structures without and with air cavity, including the effect of a waveguide-to-microstrip line transition and a branch-line balun. Both antennas have measured gain of about 12 dBi. After de-embedding the return loss, the measured insertion loss of the bond wire compensation network is only 0.07 dB at 61 GHz.