Negative feedback control is used in switched-mode power supplies to regulate the output at a desired value. The optimum design of the feedback control loop starts with understanding the characteristics of the power stage, which can be analyzed using small-signal modeling. This paper explains the fundamental idea and meaning of small-signal modeling for power supplies and explores the small-sig...

The operation dynamics of end-pumped solid-state lasers are investigated by means of a spatially resolved numerical rate-equation model and a time-dependent analytical thermal model. The rate-equation model allows the optimization of parameters such as the output coupler transmission and gain medium length, with the aim of improving the laser output performance. The time-dependent analytical th...

The nonlinear fiber coupler is considered as a Hamiltonian dynamical system with an infinite number of degrees of freedom, with the soliton states of the coupler being the singular points of this dynamical system. Numerical simulations show that arbitrary initial conditions give rise, asymptotically, to oscillations around some of the stable singular points and some amount of radiation. Example...

The design for a reversible microfluidic coupler is proposed for use with microreactors and other MEMS devices. However, real couplers will include imperfections that must be considered to fully evaluate the degree of sealing. A method is presented for applying a normally distributed surface finish with a predetermined amplitude to a perfectly flat contact surface. The method is then applied to...

Soliton switching in a nonlinear directional coupler (NLDC) with Kerr nonlinearity and coupling constant dispersion (caused by intermodal dispersion between the symmetric and the anti-symmetric modes of the coupler) is studied using the well-known variational method. Switching characteristics are calculated and discussed. It is shown that the switching characteristics of the Kerr coupler for al...

Article history: Received: 14.01.2014. Received in revised form: 01.03.2014. Accepted: 12.03.2014. Optoelectronic coupler, characterized by long life and high reliability, is one typical kind of optoelectronic devices. Accelerated degradation testing is mostly utilized to assess optoelectronic coupler storage life. However, in engineering, integrated optoelectronic coupler may be nagged with th...

Development of a 150 kW CW RF power delivery system for 1300 MHz superconducting cavities is under way at Cornell University in collaboration with MEPhI. The system is based on a twin-coupler consisting of two identical coaxial antenna-type couplers derived from the TTF III input coupler design. Because the average power is much higher than in the TTF III coupler, the required coupling is stron...

1 KIM, D.I., and YANG. G.S.: 'Broad-band design of improved hyhridring 3-dB directional coupler', IEEE Trans., 1982, MlT-30, pp. 2W2046 2 KIM, D.I., and YANG. G.s.: 'Design of new hybrid-ring directional coupler using N8 or N6 sections', IEEE Trans.. 1991, MlT-39, pp. 1179-1783 3 COUPU, J.P., PEDEN. A., and PERSON, c.: 'Analysis and design of ultra miniature hybrid ring directional coupler', Pr...

In recent years widely tunable terahertz- (THz-) wave generation from LiNbO(3) optical parametric oscillators (OPO's) has been successfully demonstrated by use of the prism output-coupler method. However, there remains a problem of large absorption loss for generated terahertz waves inside the crystal, so we investigated the cryogenic characteristics of the OPO. We achieved 125-times-higher THz...

Sound pressure measurements were made at the hearing aid microphones of 20 subjects with their in-the-ear (ITE) hearing aids and a behind-the-ear (BTE) hearing aid to determine the influence of microphone location on hearing aid input. A probe tube microphone was used to measure the difference in dB SPL between the ITE and BTE microphone locations. ITE microphone location resulted in a maximum ...