Yun-Hsueh Chuang

A wide locking range and low Voltage CMOS direct injection-locked frequency divider

A low voltage and wide locking range injection-locked frequency divider using a standard 0.18-/spl mu/m complementary metal oxide semiconductor (CMOS) process is presented. The wide locking range and the low-voltage operation are performed by adding an injection nMOS between the differential outputs of the divider that contains on-chip transformers which result in positive feedback loops to swing the output signals above the supply and below the ground potential. This dual-swing capability maximizes the carrier power and achieves low-voltage performance. The measurement results show that at the supply voltage of 0.75-V, the divider free-running frequency is 2.02 GHz, and at the incident power of 0 dBm the locking range is about 1.49 GHz (36.88%), from the incident frequency 3.27 to 4.64GHz.

Low-Phase Noise Hartley Differential CMOS Voltage Controlled Oscillator

This letter presents a novel Hartley low phase noise differential CMOS voltage-controlled oscillator (VCO). The low noise CMOS VCO has been implemented with the TSMC 0.18-mum 1P6M CMOS technology and adopts full PMOS to achieve a better phase noise performance. The VCO operates from 4.02 to 4.5GHz with 11.3% tuning range. The measured phase noise at 1-MHz offset is about -119dBc/Hz at 4.02GHz and 122dBc/Hz at 4.5GHz. The power consumption of the VCO core is 6.75mW

5-GHz Low Power Current-Reused Balanced CMOS Differential Armstrong VCOs

This letter proposes 5-GHz low power differential Armstrong voltage controlled oscillators (VCOs) based on balanced topology. One designed VCO uses two single-ended Armstrong VCOs coupled to each other in parallel by balanced structure. The other current-reused VCO uses two single-ended Armstrong VCOs stacked in series. The former VCO oscillates from 4.96 to 5.34GHz and the power consumption is 3.9mW at 0.6-V supply voltage. The latter operates from 4.98 to 5.45GHz and dissipates 2.59mW at 1.8-V supply voltage. The measured phase noises are about -116.71dBc/Hz and -110.02dBc/Hz at 1-MHz offset frequency from 5.1-GHz band, respectively. The former and the latter VCO have an advantage of low power consumption and provide a good figure of merit of about -185dBc/Hz and -180dBc/Hz, respectively

A Low-Voltage Quadrature CMOS VCO Based on Voltage-Voltage Feedback Topology

A novel low-voltage quadrature voltage-controlled oscillator (QVCO) with voltage feedback to the input gate of a switching amplifier is proposed and implemented using the standard TSMC 0.18-mum CMOS 1P6M process. The proposed circuit topology is made up of two low-voltage LC-tank VCOs, where the coupled QVCO is obtained using the transformer coupling technique. At the 0.7-V supply voltage, the output phase noise of the VCO is -124.9 dBc/Hz at 1-MHz offset frequency from the carrier frequency of 2.4GHz, and the figure of merit is -185.35dBc/Hz. Total power consumption is 5.18 mW. Tuning range is about 135 MHz while the control voltage was tuned from 0 to 0.7V

A Ring-Oscillator-Based Wide Locking Range Frequency Divider

This letter proposes a wide locking range injection locked frequency divider (ILFD) and describes the operation principle of the ILFD. The circuit is made of a dual band two-stage differential complementary metal-oxide-semiconductor (CMOS) ring oscillator and is based on MOS switches directly coupled to the differential outputs of the ring oscillator. The divide-by-two ILFD can provide wide locking range and the measurement results show that at the supply voltage of 1.8-V, the divider free-running frequencies are 1.36GHz and 2.3GHz, and at the incident power of 0dBm, the locking range is about 1.75GHz from the incident frequency 1.9GHz to 3.65GHz at low band and 2.55GHz from 2.95GHz to 5.5GHz at high band

An Integrated 5–2.5-GHz Direct-Injection Locked Quadrature

This letter presents an integrated direct-injection locked quadrature voltage controlled oscillator (VCO), consisted of a 5-GHz VCO integrated with injection locked LC frequency dividers for low-power quadrature generation. The circuit is implemented using a standard 0.18-mum CMOS process. The differential VCO is a full PMOS Colpitts oscillator, and the frequency divider is performed by adding an injection nMOS between the differential outputs of complementary cross-coupled np-core LC VCO. The measurement results show that at the supply voltage of 1.8-V, the master 5-GHz VCO is tunable from 4.73 to 5.74GHz, and the slave 2.5-GHz VCO is tunable from 2.36 to 2.87GHz. The measured phase noise of master VCO is -118.2dBc/Hz while the locked quadrature output phase noise is -124.4dBc/Hz at 1-MHz offset frequency, which is 6.2dB lower than the master VCO. The core power consumptions are 7.8 and 8.7mW at master and slave VCOs, respectively

LC

A new fully integrated, dual-band voltage controlled oscillator (VCO) is presented. The VCO is implemented in 0.18mum CMOS technology with 1.8V supply voltage. The circuit allows the VCO to operate at two resonant frequencies with two LC tanks. This VCO is configured with 2.4 GHz and 4.8 GHz frequency bands with differential outputs. The dual-band VCO operates at 2.15GHz ~ 2.75GHz and 4.75GHz ~ 4.99GHz. The measured phase-noise performances of a dual band VCO are 121.45 and 118.49 dBc/Hz at 1 MHz offset at the frequencies of 2.4 and 4.8 GHz, respectively, while drawing 3.88 mA and 3.1 mA from a 1.8V supply

VCO

This letter presents a new current reused LC-tank injection locked oscillator (ILO), which is implemented by using a standard TSMC 0.18-mum CMOS process. The ILO, used as a divide-by-two (divide2) divider, is consisted of two switching transistors stacked in series. The injection locking is performed by adding an injection nMOS between the differential outputs of the divider. The divider can operate with a lower power due to the reuse of dc current. The measurement results show that at the supply voltage of 1.5V, the divider free-running frequency is tunable from 2.11 to 2.42GHz, and at the incident power of 0dBm the locking range of the divider in the divide2 mode is about 0.9GHz (19.8%), from the incident frequency 4.1 to 5GHz. The core power consumption is 0.97mW

A CMOS Dual-Band Voltage Controlled Oscillator

This letter describes circuit techniques for obtaining divide-by-four (divide4) frequency dividers (FDs) from CMOS ring-oscillator based injection locked frequency dividers (ILFDs). The circuit is made of a two-stage differential CMOS ring oscillator and is based on MOS switches directly coupled to the differential outputs of the ring oscillator. At the supply voltage of 1.8V and at the incident power of 0dBm, for a dual-band ILFD, the divide4 ILFD can provide a locking range of 6.3% from 5.39 to 6.12GHz at low band and 5.9% from 8.84 to 9.38GHz at high band when the dc bias of MOS switches Vinj changes from 0.7 to 1.1V

A Low Power Injection Locked

A 900-MHz two-stage CMOS voltage controlled ring oscillator with wide operating frequency tuning range is presented in This work. It is implemented with a 0.18-/spl mu/m CMOS technology and biased at 1.8-V supply voltage. Its frequency tuning range is from 440 MHz to 1595 MHz. The VCO can function even biased at 1 V. And the phase noise is -73.3 dBc/Hz at 100 kHz frequency offset and -93 dBc/Hz at 1MHz.