Development of a Design Procedure for Class E Amplifiers

Here, the step-by-step design procedure for a Class E amplifier is presented. An existing Class E amplifier system is described using a systems architecture approach. The design decomposition for the case study is written so that Physical Solutions (PSs; equivalent to Design Parameters) are in terms of component parameters (such as frequency or capacitance). Coupling issues are found to arise given constraints on transistor use. The design decomposition is altered to reflect the case where an amplifier is required to power a specific load. A discussion of transistor failure enables a design procedure to be developed by observing path-dependent coupling. The design procedure is tested through the design of a real amplifier. The designed amplifier is built and its performance measured.

Propagation modeling and performance analysis of intelligent drilling communication system based on capacitance coupling approach

A new type of intelligent drilling communication system is proposed based on capacitance coupling in order to realize signal transmission in the downhole environment. A system model is established and the dispersion equation is derived. Group velocity, propagation constant, attenuation factor, and the terminal matching condition of the system are discussed according to theoretical derivations. Simulations of a large number of drill pipe units in the time domain, based on the fourth-order Runge–Kutta method, are described to verify the mathematical derivations. An experimental system of lumped parameter components has been established, which verifies the effectiveness of the simulation. Analytical and simulation results show that the carrier frequency can be as high as 0.843 MHz, and that the bandwidth of the proposed system can reach up to about 406 kHz. The results can provide a theoretical basis and comprehensive design guidance for the frequency, communication rate, and bandwidth budget of intelligent drilling communication systems.

Research on mesoscopic inductance–capacitance coupling circuit employing an unitary operator and the IWOP technique

Employing a special unitary operator and the virtue of the technique of integration within an ordered product (IWOP), we research on the quantum effects for an inductance–capacitance coupling double L–C circuit. It is found that it is convenient to research on the mesoscopic circuit with such an operator. First, eliminating the coupling term of Hamiltonian becomes easier than other methods. Second, the system’s ground state can be easily generalized into a two-mode squeezed state. Thus, the quantum fluctuations of the circuit and the variances of current in each loop are calculated, the charge-current uncertainty relation is revealed. As a result, both the uncertainty relation and fluctuation of the current in each loop become larger when [Formula: see text] is larger or [Formula: see text] is smaller.