Suspended Highly-efficient On-chip Phased Array Antenna at 60 GHz

This paper presents an on-chip millimeter-wave (mmW) phased array antenna for the next-generation wireless systems. Current silicon-based mmW antennas exhibit low radiation efficiency (~5-10%) due to lossy substrate. The proposed on-chip antenna array can achieve radiation efficiency >80% using micro-electro-mechanical systems (MEMS) processes. By suspending the radiating antennas, a low-ε_r substrate of air is formed instead of a lossy silicon substrate. The designed 5×5 (element) array is well matched at 60 GHz covering a bandwidth of 2 GHz with at least -10 dB return loss. The peak realized gain for this array is 19.7 dBi with the side-lobe level of -13 dB. Moreover, the maximum scanning volume of the designed antenna is ±45° in H plane and ±48° in E plane. As an on-chip antenna, the proposed array can be monolithically integrated on a silicon substrate. Moreover, unlike other arrays, it satisfies high realized gain and moderate scanning volume in both E and H planes, making it desirable for the next-generation communication systems.