Frequency tuning hysteresis of a dual‐resonance divide‐by‐three cross‐coupled injection‐locked frequency divider

Abstract

This paper studies the frequency tuning effect on the locking range property of a dual‐resonance 3:1 injection‐locked frequency divider (ILFD) fabricated in a foundry 0.18 μm BiCMOS process. The ILFD architecture is based on a capacitive cross‐coupled oscillator in conjunction with a resistor‐degraded dual‐resonance resonator for the locking range improvement. At a power consumption of 5.26 mW and at injection power of Pinj = 0 dBm the locking range from the measurement is from 6.2 to 12.6 GHz (68.09%). The frequency tuning range of the free‐running ILFD shows a frequency tuning hysteresis effect; at low input power level the locking range shows bipolar locking ranges and at high injection power the locking range is independent of the measured voltage tuning direction.

2:1 Injection-Locked Frequency Dividers Using Multi-Resonance Spiral-Inductor Resonator

“…Fig. 4(c) shows simulated oscillation frequency fosc of the pre-layout divide-by-2 ILFD, it shows frequency tuning hysteresis [11], [12], which is supported by the experimental data. The frequency-band transition voltage VG is lower than the opposite case while VG is tuned from high value to low value because the average capacitance is smaller at higher VG.…”

“…At VDD=1.1 V, VG=0.6 V, Vinj=1.65 V, the simulated locking range at Pinj=-15 dBm is from 4.5 GHz to 9.0 GHz, which is divided to three regions. The high-band is from 7.7 GHz to 9.0 GHz, the low-band is from 4.5 GHz to 6.4 GHz, and in between the above regions, the ILFD is locked to the input signal but the Oscillation frequency fosc is a function of VG and Vinj and the tuning range shows the hysteresis effect [11], [12], where the oscillation frequency depends on the direction of bias tuning direction. This is also an evidence that the ILFD uses a multi-resonance resonator.…”

“…In type 2, the varactor size is large, as varactor capacitance increases, the oscillation frequency switches frequency bands at certain tuning voltage from high-band to low-band and dual-band tuning range exists. A dual-resonance LC ILFD using the latter design shows that the tuning range can have two frequency bands while tuning the varactor control voltage [11]. A sharp transition in free-run oscillation frequency can be found and it is a behavior in forbidden oscillation frequency region.…”

“…At low RF injection power, the two ILFDs show two measured non-overlapped locking ranges, a property of dual-the gate with bias-controlled varactor. To confirm that the ILFDs have two resonant frequencies, the gate bias of the capacitive cross-coupled FETs is used to change the ILFD oscillation frequency and the free-running oscillation frequency shows the sharp transition in frequency tuning effect and frequency tuning hysteresis [11], [12], which is an effect of dualresonance resonator with bias-controlled varactor. At injection power of 0 dBm, the designed 5-L ÷2ILFD has one-band locking range from 2.18 GHz to 8.25 GHz.…”