A W-Band Wide Locking Range and Low DC Power Injection-Locked Frequency Tripler Using Transformer Coupled Technique

A
$W$
-band wide locking range injection-locked frequency tripler (ILFT) with low dc power consumption is presented in this paper. By using a transformer coupled (TC) topology, the proposed TC-ILFT features the following advantages: 1) the negative resistance of the cross-coupled pair is not degraded due to the proposed TC-ILFT without source degeneration, and the TC-ILFT can be operated in lower dc supply voltage as compared to the conventional ILFTs; 2) the dc bias of the injector can be properly designed for maximizing locking range; 3) the parasitic capacitance provided by the injector can be reduced due to the impedance transformation; and 4) the larger device size of the injector can be chosen enhancing the third harmonic. Moreover, the operation frequency and the locking range of this work are boosted using a multiorder resonator. A theoretical model of the proposed TC-ILFT is also established and it has been carefully verified with the experimental results. The free-running oscillation frequency of the proposed TC-ILFT is 94.51 GHz. As the input power is
${-}$
1 dBm, the measured locking range is 5.9 GHz without varactor tunning. The dc supply voltage and the power consumption are 0.7 V and 1 mW, respectively.