Digital RF transceiver architectures increasingly require quadrature (I/Q) local oscillator sinusoid generation, where the phasenoise and power consumption of the quadrature voltage controlled oscillator (QVCO) have a significant impact on the system performance. The relevance of VCO power consumption becomes even more urgent due to the demand for implementations of ultra-low power short-range ...

In this article, a novel circuit, which can function both as quadrature oscillator and universal biquad filter (lowpass, highpass and bandpass functions) is introduced. The features of the circuit are that, working as quadrature oscillator, the oscillation condition and oscillation frequency can be adjusted independently with the input bias currents: functioning as universal biquad filter, the ...

A log-domain current-mode quadrature sinusoidal oscillator based on lossless integrators is presented. The circuit is a direct realization of a first-order differential equation for obtaining the lossy and lossless integrators. Each of the log-domain lossless integrators is realized by using only NPN transistors and a grounded capacitor for achieving low-power and fast response. The proposed os...

This paper presents a fast-hopping frequency synthesizer architecture with quadrature outputs, based on subharmonic injection-locking, that is compliant with WirelessUSB/WiMedia specifications. The synthesizer features a crosscoupled quadrature digitally-controlled oscillator, that is injection locked to a sub-harmonic frequency. On-chip mixers have been implemented to measure the quadrature ac...

We have designed and developed a grating based thulium (Tm) doped fiber laser with ~150 nm tuning range which is used as the master oscillator in a master oscillator power amplifier (MOPA) thulium fiber laser system. Due to thermal instability in the grating used for tuning, the MO could produce a power up to 4.5 W, beyond which the oscillator became unstable. Injecting the seed laser into a bi...

Th is paper presents a programmable resistor using two-input floating gate MOS transistor (FGMOST). One of the two-input gates is connected to the drain and the other is connected to a tuned voltage to control the floatin g gate transistor resistance. A wide range of the programmable resistance is achieved by controlling the tuned voltage. The resistance is changed by 33% by varying the tuned v...

A simple non-linear network for amplitude stabilization in harmonic quadrature oscillator (QO) is analyzed. The oscillation startup conditions for QO topology with two operational amplifiers are used for amplitude adjustment by element values. A closed form expression for the amplitude setting resistance is derived. Total harmonic distortion (THD) is expressed as closed form function of the est...