A direct conversion modulator-demodulator with even harmonic mixers with emphasis on noise analysis is presented. The circuits consist of even harmonic mixers (EHMs) realized with antiparallel diode pairs (APDPs). We evaluate the different levels of I/Q imbalances and DC offsets and use signal space concepts to analyze the bit error rate (BER) of the proposed transceiver using M-ary QAM schemes...

In this study, both the ansatz and averaging methods are carried out for analyzing complex Duffing oscillators including undamped/conserved oscillator (CDO) damped/unconserved CDO to obtain some approximate analytical solutions. To analyze conserved CDO, it is reduced two decoupled oscillators. After that, exact solution of employed derive an approximation in terms Jacobi elliptic function. dam...

Other than scattering problems where perturbation theory is applicable, there are basically two ways to solve problems in physics. One is to reduce the problem to harmonic oscillators, and the other is to formulate the problem in terms of two-by-two matrices. If two oscillators are coupled, the problem combines both two-by-two matrices and harmonic oscillators. This method then becomes a powerf...

We present a microscopic theory of cross-correlated noise processes, starting from a Hamiltonian system-reservoir description. In the proposed model, the system is nonlinearly coupled to a reservoir composed of harmonic oscillators, which in turn is driven by an external fluctuating force. We show that the resultant Langevin equation derived from the composite system (system+reservoir+external ...

We compare the dynamics of nonlinear noisy oscillators near the two types of the Hopf bifurcation. Prior to the bifurcation, in the regime of damped oscillations around the stable focus, noise serves as a bifurcation precursor: the power spectrum includes a peak at the frequency of the self-sustained oscillations. Super-and sub-critical Hopf bifurcations differ crucially in the noise dependence...

We consider d-dimensional chains of (an)harmonic oscillators we perturb by a noise conserving energy or energy and momentum. We review the thermal conduction properties we obtained for these systems ([8], [1], [6], [2]) and conclude by several open questions.

In this paper, we consider a quantum mechanical system to model the effect of fields on evolution early universe. The consists an inverted oscillator bilinearly coupled set harmonic oscillators. We point out that role noise may be crucial in dynamics oscillator, which is analyzed using theory oscillators with random frequency. Using analogy, argue due fluctuations around its mean value, positiv...