Showing papers on "Transmission coefficient published in 1978"
TL;DR: In this article, a solution for computing the transmission characteristics of a slit in a conducting screen of finite thickness placed between two different media was developed, where the slit may be filled with Iossy material while the two regions on either side of the screen are assumed Iossless.
Abstract: A solution is developed for computing the transmission characteristics of a slit in a conducting screen of finite thickness placed between two different media. The slit may be filled with Iossy material while the two regions on either side of the screen are assumed Iossless. A magnetic line source excitation is used (TE case) which is parallel to the axis of the slit. The equivalence principle is invoked to replace the two slit faces by equivalent magnetic current sheets on perfect electric conductors. Two coupled integral equations containing the magnetic currents as unknowns are then obtained and solved for by the method of moments. Pulses are used for the expansion and testing functions. Quantities computed are equivalent magnetic currents, the transmission coefficient, the gain pattern, and the normalized far field pattern.
70 citations
TL;DR: In this article, the absorption and transformation of electromagnetic waves in the vicinity of electron cyclotron harmonics is considered and the results of a simple WKB theory and a full wave theory are compared.
Abstract: The absorption and transformation of electromagnetic waves in the vicinity of electron cyclotron harmonics is considered. The results of a simple WKB theory and a full wave theory are compared. It is found that for waves perpendicularly incident on a resonant surface (where the wave frequency equals an integer multiple of the electron cyclotron frequency), the full wave treatment is necessary to determine reflection and mode conversion coefficients, whereas, the WKB theory and full wave theory predict the same transmission coefficient. As the angle of incidence is decreased from 90°, the reflection and mode conversion coefficients become unimportant so that the full wave theory and WKB theory agree. The relevance of these processes to the heating of toroidal plasmas with high frequency waves is discussed.
59 citations
TL;DR: In this paper, it is argued that the non-symmetrical version of the treatment is in practice superior to the symmetrized version and a reason for this is proposed.
25 citations
TL;DR: In this paper, the authors considered the problem of finding the inverse relation, determining the potential of a potential barrier from the transmission coefficient, and showed that the potential can be determined from the dependence of transmission coefficient on energy and field dependence.
Abstract: Given the shape of a potential barrier $V(x)$, there is an explicit expression in the WKB approximation for the transmission coefficient for penetration of the barrier. The problem considered in this paper is to find the inverse relation, determining $V(x)$ from the transmission coefficient. It is shown that the width of the barrier at energy $E$ can be determined if the transmission coefficient is known for energies between $E$ and ${V}_{max}$, the barrier maximum. Other properties of the turning points can be deduced for potentials which can be written in terms of a parameter $\ensuremath{\lambda}$ as $V(x)={V}_{0}(x)\ensuremath{-}\ensuremath{\lambda}\ensuremath{\varphi}(x)$, if the dependence of transmission coefficient on $\ensuremath{\lambda}$ is known. For the specific case of field emission, one can find the potential $V(x)$ from the energy and field dependence of the transmission coefficient.
19 citations
Patent•
09 Aug 1978TL;DR: In this article, a microwave transistor circuit includes a pair of field effect transistors connected in cascade via a standard 50 ohm transmission line having a length equal to one-half the wavelength of the operating frequency range of the circuit.
Abstract: A microwave transistor circuit includes a pair of field effect transistors connected in cascade via a standard 50 ohm transmission line having a length equal to one-half the wavelength of the operating frequency range of the circuit. Although the field effect transistors are individually unstable at microwave frequencies, by cascading these transistors the reverse transmission coefficient is sufficiently reduced to render the overall circuit unconditionally stable. In addition, the transmission line is opened to provide physical isolation between the transistors for d.c. bias isolation and a capacitor is connected therein to provide for RF continuity.
6 citations
Book•
01 Apr 1978
TL;DR: In this article, prototype scale tests of the mooring load and wave transmission characteristics of a floating tire breakwater were conducted in the large wave tank at the Coastal Engineering Research Center.
Abstract: : Prototype scale tests of the mooring load and wave transmission characteristics of a floating tire breakwater were conducted in the large wave tank at the Coastal Engineering Research Center. Standard Goodyear Tire and Rubber Co. 18-tire modules connected to form breakwaters, 4 and 6 modules (8.5 and 12.8 meters, 28 and 42 feet) wide in the direction of wave advance, were tested in water depths of 2 and 4 meters (6.56 and 13.12 feet). Monochromatic waves with a 2.64- to 8.25-second period range and heights up to 1.4 meters (4.6 feet) were used in the tests. Test results indicate that wave transmission is mainly a function of the breakwater width to incident wavelength ratio with a slight dependence on the incident wave height. However, the mooring forces are mainly a function of the incident wave height with only a slight dependence on the incident wavelength and breakwater width. Recommended design curves for the wave transmission coefficient versus breakwater width to wavelength ratio and mooring load as a function of incident wave height are presented. (Author)
6 citations
TL;DR: In this article, the transmission coefficients for gamma and L conduction band electrons incident on GaP(111)B negative-electron-affinity surfaces within the abrupt-step model were calculated.
Abstract: The transmission coefficients are calculated for Gamma and L conduction band electrons incident on GaP(111)B negative-electron-affinity surfaces within the abrupt-step model. For large band-bending, the transmission coefficient for Gamma electrons is found to be 0.83 compared with 0.22 for L electrons. These results provide an explanation for the lower quantum yields observed by Escher and Antypas (Appl. Phys. Lett., vol.30, p.314 (1977)) for negative-electron-affinity photocathodes using indirect-gap GaAsP compared with those observed using direct-gap GaAsP.
3 citations
TL;DR: In this article, the mean momentum relaxation time of the semi-conductor was determined without previous knowledge of hole concentration and effective masses, and the experimental spectrum σ(ω) showed an increase in conductivity in addition to the one due to free-carrier relaxation mechanisms, it is caused by interband transitions between heavy holes, light holes and split-off bands.
3 citations
TL;DR: In this article, the Bertotti-Robinson metric was applied to pair production in the background of the Klein effect and the transmission coefficient was evaluated by means of the WKB approximation.
Abstract: We investigate pair production in the background of the Bertotti-Robinson metric. We study the effective potential and find the condition for particles creation to occur through the Klein effect. The transmission coefficient is evaluated by means of the WKB approximation. A Schwinger-type result is obtained for strong electric field.
3 citations
TL;DR: In this article, a theoretical analysis is made of the operation of an electro-optic switch for unpolarized light and the results are checked experimentally, showing that the minimum theoretical transmission coefficient of the switch is ~5%.
Abstract: A theoretical analysis is made of the operation of an electro-optic switch for unpolarized light and the results are checked experimentally. It is shown that this electro-optic device provides efficient Q switching of a laser whose active element is characterized by a strong initial or induced birefringence. The minimum theoretical transmission coefficient of the switch is ~5%.
2 citations
TL;DR: A model external-cavity system is investigated to describe the tuning characteristics appropriate to the various experimental procedures used in the operation of the spin-flip Raman laser.
Abstract: A model external-cavity system is investigated to describe the tuning characteristics appropriate to the various experimental procedures used in the operation of the spin-flip Raman laser. In particular a calculation is made of the amount by which internal subcavities pull the oscillation frequency away from the Raman frequency under the servocontrolled conditions used to achieve continuous tuning.
TL;DR: In this article, the radiofrequency size effect (RFSE) was investigated for two model "metals" having Fermi surfaces in the form of a cube and a corrugated sheet.
Abstract: The radiofrequency size effect (RFSE) is investigated for two model “metals” having Fermi surfaces in the form of a cube and a corrugated sheet. In the parallel-field geometry, and with the Fermi surface oriented suitably with respect to the surfaces of the plate, the nonlocal conductivities reduce to a series of delta functions, thereby facilitating the calculation (in closed form) of the response of the plate to various modes of excitation. The calculations show explicitly the structure of the field “splash” within the plate as well as the structure of the fundamental and second RFSE resonances in the rf surface impedance and transmission coefficient. The effects of multiple revolutions and secondary excitation of trajectories are exhibited, and the electron mean free path dependence of the resonances is examined.