Divide-by-Three Injection-Locked Frequency Dividers with Direct Forcing Signal

Figure 4

SPICE simulations of the circuit in Figure 3(b) with 𝑖_nl(𝑣)=𝑎₁𝑣+𝑎₃𝑣³, 𝑖_in(𝑣,𝑣_in)=𝑘𝑣_in, 𝑎₁=−12 mA/V, 𝑎₃=8 mA/V², 𝑘=−32 mA/V², 𝐿=10 nH, 𝑅=905 Ω, 𝐶=635.45 fF, 𝑉_in=0.1 V, 𝑓_in=5.6 GHz. (a) Time waveforms of the input and output signals. (b) Frequency spectrum of the output signal. (c) Arnold tongues obtained by simulating the circuit in Figure 3(b) with 𝑖_in(𝑣,𝑣_in)=𝑘𝑣_in and with 𝑖_in(𝑣,𝑣_in)=𝑘𝑣²𝑣_in.