Dual-resonance LC Research Articles

Divide-by-2 Injection-Locked Frequency Dividers Using the Electric-Field Coupling Dual-Resonance Resonator

This article designs and analyzes LC injection-locked frequency dividers (ILFDs) using dual-resonance LC resonator. The ILFD consists of two single-resonance LC-tank capacitive cross-coupled sub-ILFDs operating at 3.7 and 5.1 GHz, respectively, and the two sub-ILFDs are coupled by the electric field through a pair of metal-insulator-metal (MIM) capacitors. The die area in the Taiwan Semiconductor Manufacturing Corporation (TSMC) 0.18-μm CMOS is 0.65 × 1.023 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . By controlling the gate voltages of the switching transistors, the ILFD has three different operational modes-high-band dominant mode, low-band dominant mode, and concurrent oscillation mode. Overlapped locking range is demonstrated for the first time in the designed electric-field coupling resonator ILFD. Non-overlapped locking range is found for the ILFD manifesting an effect of the dual-resonance resonator.

A triple-band voltage-controlled oscillator with a triple-resonance resonator

This paper studies the RF property of a 0.18 μm triple-band (TB) oscillator, which is composed of a pair of switching FETs and a triple-resonance resonator. The triple-resonance resonator with three distinct resonant frequencies is made of two shunt dual-resonance LC resonators. MOS varactors with external bias control are used to change the resonant frequencies and the oscillation frequencies. High, middle, low-frequency bands are measured and simulated. At higher supply bias, the frequency tuning range shows two hysteresis loops attributed to the memory effect of varactor capacitance. Low supply operation can be used to suppress the frequency tuning hysteresis loop and the oscillator has good figure of merit.

Dual-resonance concurrent oscillator

This paper studies a new dual-band CMOS class-C voltage-controlled oscillator (VCO). The oscillator consists of a dual-resonance LC resonator in shunt with two pairs of capacitive cross-coupled nMOSFETs. The proposed oscillator has been implemented with the TSMC 0.18μm CMOS technology, and it shows a frequency tuning range with two frequency bands and a small tuning hysteresis is measured. The oscillator can generate differential signals at 2.4GHz and 6.9GHz and it also can generate concurrent frequency oscillation while the circuit is biased around the bias with frequency tuning hysteresis. With the supply voltage of VDD=1.1V, the VCO-core current and power consumption of the oscillator are 2.90mA and 3.19mW, respectively. The die area of the class-C oscillator is 0.9×0.97mm2. Overvoltage stress is applied to the oscillator, measurement indicates the concurrent oscillation is sensitive to overvoltage stress.

Divide-by-4 capacitive cross-coupled injection-locked frequency dividers

Wide locking range is an important parameter for injection-locked frequency divider (ILFD) to cope with the supply voltage variation. This paper proposes a wide locking range divide-by-4 ILFD implemented in the TSMC 0.18 μm 1P6 M CMOS process. The ILFD uses a capacitive cross-coupled voltage-controlled oscillator as the core. The dc gate bias of cross-coupled FETs is smaller than dc drain bias to optimize the power and locking range. Dual-resonance LC resonator is also used to enhance the locking range. At the drain-source bias of 1.2 V, and at the incident power of 0 dBm the measured locking range of divide-by-4 ILFD is 3.3 GHz, from the incident frequency 7.5---10.8 GHz, the percentage is 36.06%. The core power consumption is 11.83 mW. The die area is 0.883 ? 0.851 mm2.

Divide-by-3 injection-locked frequency dividers using dual-resonance resonator

This paper exploits the application of dual-resonance LC resonator in the design of wide-locking-range injection-locked frequency dividers (ILFDs). The tail-injection and direct-injection divide-by-3 ILFD circuits in a standard CMOS process are realized with a pair of cross-coupled nMOSFETs with a dual-resonance LC-resonator. The locking range enhancement techniques such as linear mixer and quality-factor degradation are used to design wide-locking range divide-by-3 ILFD. At the incident power of 0 dBm the locking range of the divide-by-3 ILFD is 4.6 GHz (43.3 %), from the incident frequency 8.3 to 12.9 GHz.

Poststress RF-drifts of dual-band LC VCO in 0.18-μm CMOS technology

This article studies the RF-property of a dual-band voltage-controlled oscillator (VCO). The designed circuit consists of a dual-resonance LC resonator and a Colpitts negative resistance cell. The dual-resonance LC resonator comprises a series-tuned LC resonator and a parallel resonant resonator. The proposed VCO has been implemented with the TSMC 0.18 μm 1P6M CMOS technology. The VCO can generate differential signals in the frequency range of 3.0–3.37 GHz and 6.95–7.40 GHz with core power consumption of 10.08 and 10.24 mW at the dc drain-source bias VDD of 1.4 V, respectively. The die area of the dual-band VCO is 0.485 × 0.800 mm2. The circuit was operated at VDD = 3 V for 8 h and significant drift in RF parameters was found. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:243–248, 2014.

Dual-band CMOS voltage-controlled oscillator with comparable outpower at both bands

A low phase noise dual-band voltage-controlled oscillator (VCO) is proposed to achieve large voltage swings at both high-frequency and low-frequency bands. The VCO consists of a dual-resonance LC resonator and a cross-coupled switching transistor pair. The dual-resonance LC resonator comprises a parallel-tuned LC resonator and a series-resonant resonator. The proposed VCO has been implemented with the TSMC 0.18-μm 1P6M CMOS technology and the core power consumption is 1.99 mW at the DC drain-source bias of 0.51 V. The VCO can generate differential signals in the frequency range of 8.19–8.77 GHz and 3.38–3.84 and it also has comparable high output voltage swings at both low- and high-frequency bands. The die area of the dual-band VCO is 0.47 × 0.748 mm2. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2349–2352, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27097