Broadband W-band on-chip Yagi antenna using superstrate for high efficiency and endfire radiation

A Silicon (Si)-based on-chip Yagi antenna with a superstrate is proposed at W-band. Conventional on-chip Yagi antenna suffers from low gain, low efficiency, and beam squinting towards the Si substrate due to the lack of ground shielding from the electrically thick, high-permittivity, and lossy Si substrate. By using the superstrate above the Yagi antenna, undesired strong coupling into Si is reduced and by properly selecting the thickness of the superstrate, endfire radiation is maintained. Furthermore, gain and efficiency are significantly improved. Simulation shows that at 82–108 GHz, the on-chip antenna with the superstrate exhibits a higher endfire gain (> 0 dBi) and higher efficiency (> 60%), which is comparable to those of an off-chip antenna.