115GHz Low-Cost Oscillator-Integrated Reflectarray

This paper presents a low-cost 115 GHz oscillator-integrated folded reflectarray (FRA) for the first time. The oscillator generates a millimeter-wave signal beyond 100 GHz, which is significantly higher than the maximum oscillation frequency ( $f_{\max}\approx 70$ GHz) of the employed $0.18\ \mu\mathrm{m}$ CMOS process. Then this oscillator is directly wire-bonded with a wideband antenna to feed the FRA in printed circuit board (PCB). The FRA features high gain to increase the equivalent isotropic radiated power (EIRP) of the transmitter. A quasi-double-arrow-shaped element which is robust for fabrication tolerance, is proposed for polarization rotating and phase compensation. Experimental results show that, the proposed oscillator-integrated FRA has a 9.5 dB EIRP enhancement compared with that of the feed antenna. The proposed oscillator-integrated FRA features low cost, planar structure, and high EIRP without bulky lens.