Divide‐by‐2 injection‐locked frequency divider exploiting an 8‐shaped inductor

Abstract

This letter presents a wide‐band 2:1 injection‐locked frequency divider (ILFD) in the 0.18 μm BiCMOS process with circuit model of class‐AB. The ILFD uses an 8‐shaped inductor in shunt with parasitic capacitors as the resonator, and it also employs two capacitive cross‐coupled pairs to generate negative resistance for oscillation. The gate biases of capacitive cross‐coupled pairs are fully utilized to tune the free‐running ILFD oscillation frequency. At the power consumption of 2.064 mW and the input power of 0 dBm, the locking range frequency is 71.3% (from 3.7 to 7.8 GHz) and the figure of merit (FOM) is 34.54. As compared to other ILFDs using octagonal inductors, this ILFD has low EM radiation level and less sensitivity to received EM noise.

Using tail current phase shift technique to improve locking range injection‐locked frequency divider

“…ILFDs are more attractive than other frequency dividers due to their lower power consumption and higher frequency performance. Nevertheless, reaching an ILFD with a wide frequency range is still challenging 16–18 …”

“…In Lee et al, 16 a phase tuning technique is applied to get a 25% improvement in LR, which is not enough to cover multiple applications. Varactor was utilized to improve the LR by changing center frequency, 17 which could reach a 37% LR. However, the varactor's low‐quality factor has led to the decline of phase noise.…”

“…Nevertheless, reaching an ILFD with a wide frequency range is still challenging. [16][17][18] Many studies have been performed to improve the LR of the ILFDs and multipliers. Direct injection 7 proposed an LR enhancement technique using a phase shifter circuit.…”

Injection-Locked Frequency Sixtuplers in 90 nm CMOS by Using the Push-Push Doubler

“…LC voltage-controlled oscillators (VCOs) with inductive load are essential parts of all RF-integrated transceivers and they normally integrate with output buffers for driving other circuits or for measurement purposes. Literature has shown various inductor topologies, which include tapered inductors [11] and 8-shaped inductors [12]. The latter inductor uses one-turn [13], 2-turn [14], or 3turn [12].…”

“…Literature has shown various inductor topologies, which include tapered inductors [11] and 8-shaped inductors [12]. The latter inductor uses one-turn [13], 2-turn [14], or 3turn [12]. A twisted inductor normally has two lobes with farfield magnetic field generation in opposite directions to offset each other in the location sitting between the symmetric axis of the two lobes.…”