CMOS THz Generator With Frequency Selective Negative Resistance Tank

This paper reports a CMOS terahertz oscillator with a novel frequency selective negative resistance (FSNR) tank to boost its operating frequency. The demonstrated oscillator can operate at a fundamental frequency of about 0.22 THz, exceeding the CMOS device cutoff frequency of f
_T
. The proposed architecture suppresses undesired 2nd and odd harmonics and boosts the fourth-order harmonic (0.87 THz), which radiates through an on-chip patch antenna. The THz oscillator's output spectrum is profiled by using a Michelson interferometer. The oscillator circuit consumes 12 mA from a 1.4 V supply and occupies a 0.045 mm2 die area in a 65 nm CMOS technology.