SiP-based 60GHz 4×4 antenna array with 90nm CMOS OOK modulator in LTCC

A 60GHz 4×4 circular polarized (CP) patch array antenna with a 90nm CMOS OOK modulator are designed and integrated in low temperature cofired ceramic (LTCC) substrate to form a SiP-based transmitter. By applying a stripline sequential rotation feeding scheme, the CP array exhibits a wide impedance bandwidth (VSWR<2) and 3dB axial ratio (AR) bandwidth, both over 8GHz. It has a beam-shaped pattern with a 3dB beamwidth of 20° and a peak gain of 16.8dBi. The CMOS modulator includes a 60GHz oscillator and switchable amplifiers to provide the OOK modulation. By applying a bond wire compensation scheme and low-loss transition optimization, the CMOS modulator is successfully integrated into the package with 2mil 500µm long bond wires. The final fabricated prototype measures only 22×13×1.4mm³. The 60GHz SiP transmitter is tested with a commercial receiver and a data rate of 2Gbps is demonstrated. The energy usage at 2Gb/s is only 13.2pJ/bit for the modulator.