Gain and Efficiency Enhancement of a 77 GHz On-Chip Antenna through AMC and Superstrate Package

Abstract

On-chip antennas present an excellent solution for higher integration levels with the lower number of off-chip components and lower cost, however, their efficiencies are much lower due to lossy Si substrates. In this paper, we present a novel combination of Artificial Magnetic Conductor (AMC) surface and a package which acts as a superstrate as well to enhance the on-chip antenna efficiency. Designed in standard 0.18 µm CMOS technology at 77GHz frequency band, the CPW-fed on-chip monopole antenna is a good candidate for automotive radar systems. Since the package of the chip acts a superstrate, it is not a mere protector of the chip but also provides functionality, qualifying this design as System-on-Package (SoP). The combination of the optimized AMC surface and superstrate package enhance the radiation efficiency of the antenna to 54.37% and the gain to 2.4dBi, achieving 22.1% efficiency enhancement and 9.1 dB gain enhancement as compared to the standalone on-chip antenna.