This paper presents a fully integrated 20-GHz frequency synthesizer based on an integer-N fourth-order type-II phase-locked loop (PLL). The PLL synthesizer employing a cross-coupled LC VCO was fabricated in a 0.13-μm SiGe:C BiCMOS process with a small chip area of 0.48 mm. The VCO core current is 4 mA. The full tuning range of the VCO is 2.21 GHz from 19.9 to 22.11 GHz, and the PLL can synthesi...

This paper presents a high dynamic range (DR), power efficient VCO-based continuous time ΔΣ modulator (CTDSM). It introduces a simple, robust and low power fully digital phase extended quantizer (PEQ) that doubles the VCO quantizer resolution compared to conventional XOR-based phase detector with minimum overhead. A tri-level resistor DAC is also introduced as complementary to the new quantizer...

A digital voltage-controlled oscillator (VCO) is described which uses frequency multiplication and division to achieve very wide bandwidth. The VCO uses current-mode logic and does not require reactive elements such as inductors, capacitors or varactors. A novel, fully symmetric exclusiveOR (XOR) circuit was developed which uses product pairs and emitter-coupled logic. To achieve the highest pe...

This paper focuses on the modeling and analysis of phase-locked loops in the presence of continuous wave (CW) interference such that the operating vulnerability to CW jamming and interference can be accessed. The loop phase error is characterized, and the conditions under which the loop remains locked in frequency to the desired carrier are presented. Analysis is conducted for arbitrary offsets...

High Tc superconductor (HTS) technology has been used to develop an advanced high Q resonant circuit and its devices. With a HTS, a very high Q circuit can be achieved; consequently special aspects such as high voltage generation and high current control can be theoretically and practically realized. Theoretical study has been carried out, as well as a practical approach has been made for the c...

BACKGROUND Although parameters obtained during submaximal exercise are known to be useful for predicting mortality in cardiac patients, it has been a matter of debate whether the submaximal parameters are superior to peak oxygen uptake (VO(2)). For this purpose, we aimed to determine the best index among exercise variables in predicting long-term mortality in patients with chronic heart disease...

Two types of lipase, Candida rugosa lipase (CRL) and porcine pancreas lipase (PPL), were used to hydrolyze virgin coconut oil (VCO). The hydrolysis process was carried out under four parameters, VCO to buffer ratio, lipase concentration, pH, and temperature, which have a significant effect on hydrolysis of lipase. CRL obtained the best hydrolysis condition at 1 : 5 of VCO to buffer ratio, 1.5% ...

This paper describes the simulations performed in order to evaluate expected performance of the voltage-controlled oscillator (VCO) based on differential ring oscillator with SCFL delay cells in 0.5μm GaAs MESFET technology. The ring oscillator structures with buffer cells are also simulated. The frequency range and tuning sensitivity are extracted. Finally, jitter simulations are performed in ...

A new concept for quadrature coupling of LC oscillators is introduced and demonstrated on a 5GHz CMOS VCO. It uses injection-locking through commonmode inductive coupling to enforce quadrature. The technique provides quadrature over a wide tuning range without introducing any phase noiseor power consumption increase. The realized VCO is tunable between 4.6GHz and 5.2GHz and measures a phase noi...

In this paper , a dual-slope phase frequency detector and charge pump architecture for fast locking of PLL is proposed and analyzed. The proposed PLL circuit is designed based on the 0.11um CMOS process with 1.2V supply voltage. The modified delay cell circuit of Ring Oscillator is used in the design of VCO and the frequency range of VCO is from 23MHz to 522MHz. This frequency synthesizer has a...