Generating terahertz signals in 65nm CMOS with negative-resistance resonator boosting and selective harmonic suppression

Terahertz signals have been successfully generated in 65nm CMOS by: 1) stacking a negative-resistance resonator in parallel to the conventional resonant tank to boost the fundamental oscillation to 0.22 THz; and by 2) selectively suppressing the odd and 2^nd harmonics to boost the 4^th and 6^th harmonics in the terahertz regime. Consequently, we have detected 4^th and 6^th harmonic signals through on-chip antenna radiation at 0.87 and 1.31 THz, respectively, by using a Michelson interferometer. To our best knowledge, this is the first time a signal beyond 1 THz is generated by silicon based semiconductor.