Voltage-controlled oscillator

About: Voltage-controlled oscillator is a research topic. Over the lifetime, 23896 publications have been published within this topic receiving 231875 citations. The topic is also known as: VCO.

-Boosted Common-Gate LNA and Differential

Abstract: The demand for radio frequency (RF) integrated circuits with reduced power consumption is growing owing to the trend toward system-on-a-chip (SoC) implementations in deep-sub-micron CMOS technologies. The concomitant need for high performance imposes additional challenges for circuit designers. In this paper, a -boosted common-gate low-noise amplifier (CGLNA), differential Colpitts voltage-controlled oscillators (VCO), and a quadrature Colpitts voltage-controlled oscillator (QVCO) are presented as alternatives to the conventional common-source LNA and cross-coupled VCO/QVCO topologies. Specifically, a -boosted common-gate LNA loosens the link between noise factor (i.e., noise match) and input matching (i.e., power match); consequently, both noise factor and bias current are simultaneously reduced. A transformer-coupled CGLNA is described. Suggested by the functional and topological similarities between amplifiers and oscillators, differential Colpitts VCO and QVCO circuits are presented that relax the start-up requirements and improve both close-in and far-out phase noise compared to conventional Colpitts configurations. Experimental results from a 0.18- m CMOS process validate the -boosting design principle.

High-speed point-to-point modem-less microwave radio frequency link using direct frequency modulation

Abstract: A point-to-point microwave radio link that operates in a Frequency Division Duplex (FDD) mode using direct digital modulation with a Continuous Phase-Frequency Shift Keyed (CP-FSK) scheme. The transmit signal is generated by a circuit that uses a Voltage-Control Oscillator (VCO) operating in a microwave radio band. The VCO is deviated over a narrow frequency range that is reduced by a predetermined factor. The output of the VCO is then frequency multiplied by the predetermined factor to produce the modulated microwave output signal at the desired band. The deviation frequency of the VCO is thus chosen to be the reciprocal of the multiplication factor times the transport bit rate.

Design of Adaptive Multimode RF Front-End Circuits

Abstract: Migration towards higher data rates and higher capacities for multimedia applications, and provision of various services (text, audio, video) from different wireless standards with the same device require integrated designs that work across multiple standards, can easily be reused, and achieve maximum hardware share at minimum power consumption. This can be achieved by using adaptive circuits that are able to trade off power consumption for performance. The design of an adaptive multimode image-reject downconverter (oscillator and two mixers) is presented in this paper. In the highest performance mode, the image-reject downconverter (the quadrature mixers) has an IIP3 of +5.5 dBm, a single-side band noise figure of 13.9dB and a conversion gain of 1.4 dB, while drawing 10mA from a 3 V supply. The adaptive oscillator achieves -123 dBc/Hz phase noise at 1MHz offset from a 2.1 GHz carrier with a bias current of 6 mA in the highest performance mode. Adaptivity in the downconverter is achieved by trading off RF performance for current consumption, ranging from 10 mA for the relaxed mode (e.g., DECT) to 20 mA in the highest performance mode (e.g., DCS1800) of operation

14 MHz micromechanical oscillator

Abstract: Operation of a 14 MHz micromechanical oscillator is demonstrated and analyzed. Single-crystal silicon microbridge with submicron electrode gaps is utilized as the resonator element. The oscillator shows a noise floor of −112 dBc/Hz and a near-carrier noise of −90 dBc/Hz at 1 kHz offset. The oscillator noise is dominated by amplifier noise. By comparing the oscillator performance with conventional quartz oscillators, advantages and limitations of the micromechanical components in RF-technology are discussed.

Injection-Locked CMOS Frequency Doublers for $\mu$ -Wave and mm-Wave Applications

Abstract: On-chip frequency generators for high frequency applications suffer from degradation of key passive components, variable capacitors in particular. In this framework, frequency multipliers can play a key role, allowing the design of voltage-controlled oscillators running at a frequency lower than required with advantage in terms of signal spectral purity and frequency tuning range. In this paper we present two injection locked frequency doublers for Ku-band and F-band applications respectively. Despite differences in implementation details, the same topology where a push-push pair injects a double frequency tone locking an autonomous differential oscillator is adopted. The circuits require limited input signal swing and provide a differential output over a broad frequency range. Dissipating 5.2 mW, the Ku-band multiplier, realized in a 0.13 μm CMOS node, displays an operation bandwidth from 11 GHz to 15 GHz with a peak voltage swing on each output of 470 mV. The F-band multiplier, realized in 65 nm CMOS technology, displays an operation bandwidth from 106 GHz to 128 GHz with a peak voltage swing on each output of 330 mV and a power dissipation of 6 mW. A prototype including the multiplier, driven by a half-frequency standard LC-tank VCO, demonstrates an outstanding 13.1% tuning range around 115 GHz.