Widely tunable THz source based on constructive wave oscillator in a 130-nm SiGe BiCMOS

Abstract

This paper presents a novel tunable THz source based on a six-section Constructive Wave Oscillator (CWO) designed in a 130-nm SiGe BiCMOS process. Unlike traditional THz source designs that rely on VCOs and frequency multipliers, this approach offers a simple, compact, and yet power-efficient solution. The proposed architecture achieves a \(10 \%\) tuning range and generates phasor signals beyond the conventional I/Q (\(0^{\circ }\)–\(90^{\circ }\)) type, enabling new possibilities for modulation schemes and harmonic cancellation. The design generates a 0.285 THz signal based on a tunable CWO operating at 95 GHz, with 95 GHz signals distributed along the ring with \(60^{\circ }\) phases. The THz source combines these signals to produce a signal at \(3f_0\) using a harmonic cancellation technique. The circuit occupies a compact area of 0.46 × 0.51 \(\hbox {mm}^2\) and dissipates only 60 mW of DC power from a 2V supply. The tunable THz source demonstrates a simulated -22 dBm output power and a phase noise of -76 dBc/Hz at a 1 MHz offset, making it a significant advancement in the field of THz signal generation.