This paper presents three novel architectures for high-efficiency amplifiers relying on new harmonic-tuning techniques. These methods yield high-efficiency power amplifiers and reduce unwanted harmonic radiation from the transmitter front end. The first method uses the active integrated-antenna approach to perform harmonic tuning. The second method uses a nontraditional periodic microstrip filt...

In this article, based on the Euler-Bernoulli beam theory, the large-amplitude vibration of multiwalled carbon nanotubes embedded in an elastic medium is investigated. The method of incremental harmonic balance is implemented to solve the set of governing nonlinear equations coupled via the van der Waals (vdW) interlayer force. The influences of number of tube walls, the elastic medium, nanotub...

In this paper, an application of the Harmonic Balance Method (HBM) for analysis Axial Flux Permanent Magnet Generator (AFPMG) is carried out. Particular attention was paid to development mathematical model equations allowing estimate machine properties, without having use quantitative solutions. The methodology used here allowed precise determination Fourier spectra with respect winding current...

In this paper, a modified harmonic balance method based an analytical technique has been developed to determine higher-order approximate periodic solutions of a conservative nonlinear oscillator for which the elastic force term is proportional to x. Usually, a set of nonlinear algebraic equations is solved in this method. However, analytical solutions of these algebraic equations are not always...

This paper deals with the accuracy of a numerical time integration scheme, the implicit Generalizedα method, when applied near resonant conditions in periodic steady-state vibrations of elastic linear and nonlinear systems. In order to evaluate errors, analytical solutions of Frequency Response Functions (FRFs) are determined by using the Harmonic Balance method in singleand two-degrees-of-free...

In this paper, Newton Harmonic Balance Method (NHBM) is applied to obtain the analytical solution for an electron beam injected into a plasma tube where the magnetic field is cylindrical and increases towards the axis in inverse proportion to the radius. Periodic solution is analytically verified and consequently the relation between the Natural Frequency and the amplitude is obtained in an ana...

The chapter addresses bifurcations of limit cycles for a general class of nonlinear control systems depending on parameters. A set of simple approximate analytical conditions characterizing all generic limit cycle bifurcations is determined via a first order harmonic balance analysis in a suitable frequency band. Moreover, due to the existing connection between limit cycle bifurcations and rout...

In the present work explicit formulas for analyzing the birth of limit cycles arising in the Chua’s circuit through a Hopf bifurcation is provided. A local amplitude equation is derived using a frequency domain approach and harmonic balance approximations. Furthermore, the first Lyapunov index used to detect degenerate Hopf bifurcations is derived in terms of the parameters of the nonlinear cir...

We present an efficient simulation technique to account for the thermal spreading effects of surface metallizations in the self-consistent dynamic electro-thermal analysis of power microwave devices. Electro-thermal self-consistency is achieved by solving the coupled nonlinear system made of a temperature dependent device electrical model, and of an approximate description of the device thermal...

The calculation of orbital fluctuations and of the phase-orbital correlation within Floquet-based noise analysis of autonomous systems requires the availability of all the direct and adjoint Floquet eigenvectors associated with the noiseless limit cycle. Here the authors introduce a novel numerical technique for their frequency domain determination. The algorithm is entirely based on the Jacobi...