Artificial dielectric enabled antennas for high frequency radiation from integrated circuits

At millimeter and sub-millimeter wave frequencies, electronic circuits and antennas are often located on the same semiconductor chip to facilitate their interconnection. However, on-chip antennas are characterized by very poor radiation efficiency and extremely narrow bandwidth. This is because they are situated at small electrical distance from a ground plane that shields the antenna from the lossy bulk. High-permittivity superstrates can be located above the antennas to improve the impedance properties, but they support the propagation of surface waves which reduce the efficiency. Here we propose the use of artificial dielectric (AD) superstrates above the antennas to improve significantly their performance. Because of their anisotropy, AD slabs do not support surface waves, thus enabling high-efficiency designs. To clarify the concept, we investigate the properties of a simple dipole antenna on chip in terms of impedance and efficiency. Full-wave simulations predict efficiency up to 87% with the presence of the AD.