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.