On-Chip Leaky Wave Antenna With 220–500 GHz Bandwidth and 128° Beam Scanning in 65-nm CMOS Process

This paper presents a terahertz on-chip leaky-wave antenna (LWA) implemented in 65- nm CMOS technology, featuring ultra-wide bandwidth and enhanced beam coverage. The antenna employs a periodically alternating transmission structure composed of a substrate integrated waveguide (SIW) and a microstrip line (MSL). At each SIW-MSL interface, discontinuities in surface impedance and wave mode are simultaneously generated, introducing periodic perturbations. This impedance-mode hybrid modulation mechanism facilitates efficient radiation of theN= -1 space harmonic across a 77.8% relative bandwidth. Moreover, by modifying the SIW-MSL transition and optimizing the interface spacing, the open stopband (OSB) effect is effectively suppressed. Finally, an on-chip 7-element LWA with a footprint of 0.5×4 mm2is fabricated and experimentally characterized, demonstrating a wide -10-dB impedance bandwidth from 220 to 500 GHz, a wide beam scanning range from −54° to +74°, a peak gain of 10.3 dBi, and a side-lobe level ranging from −12 dB to −6.6 dB. Benefiting from these features, the proposed on-chip LWA is a promising candidate for fully integrated silicon-based terahertz systems.