-In this paper an analysis and stochastic characterization of optimally controlled systems in the presence of environmental disturbances, additive input and observation noise, and subject to discontinuous-type parameter uncertainties is considered. As an illustrative example, the control of a spinning spacecraft is considered and some quantitative aspects of the stochastic behavior of the contr...

This paper aims to introduce a quadrature VCO (voltage control oscillator) which applies superharmonic coupling. The presented quadrature VCO is suitable to be used, both with 2 × subharmonic mixers, as well as 4× subharmonic mixers. It would be impossible to avoid the presence of harmonics in CMOS VCO circuits. These harmonics are in general, undesirable signals which tend to accompany the des...

This paper proposes an RF signal generator using a time domain harmonic suppression technique based on Fourier series analysis. The circuit consists of four differential ring voltage control oscillators (VCO’s) with phase differences and the pulse signal summing circuit. By summing pulse signals from VCO’s with appropriate phase differences determined by Fourier series in time domain, the third...

This paper attempts to list challenges and possible solutions for designing integrated voltage controlled oscillators (VCOs) in wireless products. Such challenges include oscillation frequency, frequency coverage, linearity of tuning curves, phase noise, power consumption, oscillation amplitude variations, sensitivity to process, supply voltage, and temperature variations (PVT), coupling to and...

This paper presents a 20 GHz push-push VCO realized by a 10 GHz super-harmonic coupled quadrature oscillator for a quadrature 60 GHz frequency synthesizer. The output nodes are peaked by a tunable second harmonic resonator. The proposed VCO is implemented in 65 nm CMOS process. It achieves a tuning range of 3.5 GHz from 16.1 GHz to 19.6 GHz with a phase noise of −106 dBc/Hz at 1 MHz offset. The...

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...

In this article, the secure transmission of data is being realized on the basis of the synchronization of two chaotic systems. The transmitted signal is only the sign of a projection of the state. This has the advantage of making the transmission not very sensitive to the noises of transmission and the attenuation of the transmitted signal without using a VCO (Voltage Control Oscillatory) into ...