A Novel CMOS High-Power Terahertz VCO Based on Coupled Oscillators: Theory and Implementation Y ahya M. Tousi, Member , IEEE

Abstract

We introduce a novel frequency tuning method for high-power terahertz sources in CMOS. In this technique, mul- tiple core oscillators are coupled to generate, combine, and deliver t h e i rh a r m o n i cp o w e rt ot h eo u t p ut node without using varactors. By exploiting the theory of non linear dynamics, we control the coupling between the cores to set their phase shift and frequency . Using this method, two high-power terahertz VCOs are fabricated i na6 5n mL Pb u l kC M O Sp r o c e s s .T h efirst one has a measured output power of 0.76 mW at 290 GHz with 4.5% tuning range and the output power of the second VCO is 0.46 mW at 320 GHz with 2.6% tuning range. The output power of these signal sources is 4 orders of magnitude higher than previous CMOS VCOs an di s even higher than VCOs implemented in compound semiconduc- tors with much higher cut-off frequencies.