Terahertz On-Chip Aperture Antenna With Through Substrate Vias for Enhanced Gain and Chip-Size Insensitivity in InP Technology

In this article, an on-chip aperture antenna in indium phosphide (InP) technology is proposed for terahertz transceivers. Terahertz on-chip antennas are often directly connected to the amplifier, and the bulky substrate of active circuits affects the impedance and radiation characteristics of the antenna. In order to obtain robust antenna performances against the uncertain chip size of the active circuits and simultaneously enhance the gain and radiation efficiency, through substrate vias (TSVs) are utilized to form the quasi-substrate integrated waveguide (SIW) cavity. Furthermore, a dual-mode aperture antenna with the quasi-SIW cavity is proposed, and the high-order mode of the substrate integrated cavity is introduced in proximity to the aperture mode to broaden the impedance bandwidth. The nonbroadside radiation pattern of the even-TM120 mode is successfully reshaped by the radiating apertures. Then, a custom-designed ground package is analyzed to fix the chip and further improve the broadside gain. Finally, the proposed antenna is fabricated and measured. Benefiting from the techniques proposed above, a competitive gain of
$\sim $
8.0 dBi is obtained.