A novel THz-enhanced dipole antenna using second-order high impedance surface resonance for MM imaging and sensing

In this paper, an improved technique is presented to enhance Terahertz (THz) and Millimeter Wave (MMW) On-Chip antenna performance on low-resistive silicon substrates using High-Impedance Surfaces (HIS). These surfaces are directly printed onto the metal layers of ST Microelectronics´ BiCMOS 55 nm technology Back End Of Line (BEOL) and do not require any special post-process (micromachining, Through Silicon Vias (TSV), etc.). They provide a remarkable improvement in terms of gain and efficiency. For example, the gain of an integrated dipole antenna at 60 GHz is improved by 7 dBi, and 40% efficiency is obtained, against 23% for the basic dipole without HIS. Furthermore, due to the frequency limitations induced by the fixed height of the silicon substrate, higher-order resonances of HIS are exploited to enhance performance at higher frequencies. The second-order resonance of an HIS is exploited with a 220-GHz antenna for millimeter-wave imaging applications. Thus, the gain is upgraded by the order of 15 dBi.