This paper explores a continuous time (CT) sigma delta ( ) analog-to-digital converter (ADC) based on a dual-voltage-controlled oscillator (VCO)-quantizer-loop structure. A thirdorder ̄lter is adopted to reduce quantization noise and VCO nonlinearity. Even-order harmonics of VCO are signi ̄cantly reduced by the proposed dual-VCO-quantizer-loop structure. The prototype with 10MHz bandwidth and 400...

In this letter, we present a new linearization method for a voltage controlled oscillator (VCO)-based quantizer in an analog-to-digital converter (ADC). The nonlinearity of the VCO generates unwanted harmonic spurs and reduces the signal-to-noise and distortion ratio (SNDR) of the VCO-based quantizer. This letter suggests a frequency-to-current feedback method to effectively suppress harmonic d...

The robust voltage-controlled oscillator is presented by using the constant current reference and the ring oscillator for the embedded system application. The constant current reference generates the constant current for the succeeding ring oscillator to produce a stable 4MHz oscillation frequency. The proposed VCO circuit was fabricated in a 0.35 μm CMOS technology and worked with a supply vol...

PURPOSE Being overweight/obese, having hypertension, and being postmenopausal are risk factors for the development of congestive heart failure (CHF). A characteristic of CHF is an abnormal V(E)/VCO(2) slope, which is predictive of mortality in patients with CHF. Although the V(E)/VCO(2) slope is well established in CHF patients, little is known regarding interventions for "at-risk" populations....

A low phase noise, low dissipated power and small sized Ka-band voltage-controlled oscillator (VCO), using dual cross-coupled pair configuration and capacitance-splitting technique is presented. The Ka-band VCO circuit uses 0.15 μm GaAs pHEMT technology. The VCO has low phase noise, of 116.36 dBc/Hz, at a 1 MHz offset and can be tuned from 30.5 to 31.22 GHz. The figure of merit (FOM) is -192.36...

This paper describes the design and analysis of a fully integrated CMOS Voltage Controlled Oscillators (VCO). The VCO is designed in TSMC 0.25um single-poly, 5-metal CMOS process. It is designed to have a tuning range greater than 15% covering the frequency bands of WLAN 802.11b while consuming less than 7 mW of power. A generalized linear phase noise model is developed to predict VCO performan...

A 1.6-GHz LC voltage-controlled oscillator has been implemented in a 0.5-μm CMOS process. Bond wires, with their low series resistance, provide a resonant tank with high Q. Complementary crosscoupled PMOS and NMOS transistors enhance the single-ended symmetry at each of the resonant nodes to reduce close-in phase noise. At an offset frequency of 100 kHz, the measured phase noise is -95 dBc/Hz a...

This paper presents a new design of complementary oxide semiconductor voltage controlled oscillator (CMOS VCO) for improve tuning range and phase noise with low power consumption. Design is area efficient and easy to implement. Design is carried out in cadence and schematic editor using 180 nm technology. Simulation is done and performance results are reported. Results have been compared with e...

A 1.2V 5GHz low-cost voltage-controlled oscillator (VCO) with active common mode feedback has been implemented in a CMOS/RF 90nm technology for a robust I/Q generation using a frequency divider-by-2 (DIV2). As the input common mode of the DIV2 affects critically its performance, a calibration method to correct the output common mode of the VCO has been proposed and validated through post-layout...