This letter describes the power absorption of a cylindrical man model placed near a flat reflector exposed to TE microwave. The numerical results show that the absorption is in some cases an order of magnitude or more greater than that of the man model without a reflector.

A photonic/video hybrid system for optical information processing by synthesis of the coherence function is proposed. Optical coherence function can be synthesized to have delta-function-like shape or notch shape by using direct frequency modulation of a laser diode with an appropriate waveform. Therefore, by choosing only the interference component in the interferometer, information processing functions can be obtained. The photonic/video hybrid system proposed provides a novel way to choose the interference component, which can improve the spatial resolution compared with our previous system with holographic technique. Selective extraction two-dimensional (2-D) information from a three-dimensional (3-D) object is successfully performed in basic experiments.

In this paper, mutual coupling S21 between RMSA (ring-shaped microstrip antenna) elements was estimated by the EMF method based on the cavity model. Then, the validity of the proposed method was tested by experiments. The experiments confirmed satisfactory agreement between the computed and experimental data for S21 in both E- and H-plane arrangements. In addition, a circularly polarized planar array composed of R-MSA elements was designed on the basis of the data of S21. The experimental results of such a planar array demonstrated high performance in radiation pattern as well as axial ratio property. Furthermore, the active reflection coefficient Γ in the R-MSA array was also investigated in both equilateral and square arrangements. The computed results of active reflection coefficient in the array demonstrated high performance in both arrangements.

The scattering characteristics of a waveguide T-junction with an inductive post are analyzed by the port reflection coefficient method (PRCM), combined with the mode-matching technique. Variation behaviors of the scattering parameters are provided as a function of the operating frequency and the dimensions of the junction. The results are helpful for the design of power dividers using this type of T-junction configuration.

Radio disturbances of digital microwave links are likely to increase as man-made structures screen the radio propagation paths, and unwanted waves reflected or scattered by the structures interfere with radio signals. This paper describes a practical method for evaluating the influence of propagation impairments due to man-made structures on digital microwave links and provides some model calculations of those impairments. Since multilevel and quadrature modulation techniques are employed to achieve high spectral efficiency for recent digital transmissions, not only average level attenuation but also in-band distortion and intersymbol interference have to be taken into account. Propagation distortion, diffraction loss and cross-polar interference due to reflected and scattered waves from man-made structures such as buildings and conductor structures are evaluated.

The subject is the horizontal coil's temperature rise in DY for high frequency by being unavoidable for the tendency of more information on display monitor equipments. Writers made the temperature-balance model from a point of view that this temperature rise is coming from the heat rise and the conductivity, and we expressed the temperature rise of DY by using amount of the heat rise and conductivity characteristics of each element. Also, we indicated the method to decide about the selection of the wire size of coils, the section area and deflection sensitivity, with regard to reducing the temperature rise. We confirmed the effect of the temperature rise reduction by about 9 on products, under the condition of 64 kHz horizontal frequency.

This paper describes the design of the reflective concurrent object-oriented specification language RMondel. RMondel is designed for the specification and modeling of distributed systems. It allows the development of executable specifications which may be modified dynamically. Reflection in RMondel is supported by two fundamental features that are: Structural Reflection (SR) and Behavioral Reflection (BR). Reflection is the capability to monitor and modify dynamically the structure and the behavior of the system. We show how the features of the language are enhanced using specific meta-operations and meta-objects, to allow for the dynamic modification of types (classes) and instances using the same language. RMondel specification can be modified by adding or modifying types and instances to get a new adapted specification. Consistency is checked dynamically at the type level as well as at the specification level. At the type level, structural and behavioral constrations are defined to preserve the conformance of types. At the specification level, a transaction mechanism and a locking protocol are defined to ensure the consistency of the whole specification.

B-ISDN telecommunication systems will require signal processing speeds up to 600 Mbps or more. We must therefore consider the affects of signal reflection, signal attenuation, time dalay, and so on when designing these systems. The higher the signal speed, the larger the electrical noise induced around the connector, especially in the plated through holes (PTHs) area. This paper presents the results of our investigation focused on connector mounting configurations in the signal transmission line, especially whether or not signals transmit through the PTH in a printed circuit board (PCB). How the signal reflection characteristics depend upon transmission line configurations are discussed and experimental results and simulation analyses for a transmission line system using a small miniature A-type (SMA) connector as an example are performed. It is suggested that designs for future high-speed signal transmission circuits take into account the PTH diameter and/or the PTH pitch conditions, values for which can be determined from simulation analysis.

The optical characteristics of the fiber loop polarizer are investigated considering the birefringence in the fiber loop. The experimental and the theoretical spectrum transmissions agree well with each other. The extinction ratio and the insertion loss of the fiber polarizers have been improved for practical use.

This paper reports on a new dynamic scanning force microscope (SFM), in which the piezoelectric microcantilever is utilized for the lever excitation and displacement sensing. Piezoelectric cantilevers can detect their deflection without external sensing elements and be vibrated with no oscillator outside. The cantilever integrated with the deflection detector and the oscillator changes the conventional construction of a dynamic SFM and expands its range of applicability. The microcantilever used consists of a ZnO layer sandwiched with Au electrodes deposited on a thin beam of thermally grown SiO2. The length, width and thickness of the lever are 125 µm, 50 µm and 3.5 µm, respectively. We have characterized this cantilever by measuring the charge spectrum and the frequency dependence of the admittance. From the charge spectrum the mechanical quality factor measured 300 in free vibration. Typical piezoelectric constant of the ZnO film was estimated approximately as 80% of single-crystal's value. The piezoelectric cantilever can be vibrated by applying the voltage with the frequency near the resonance to the piezoelectric layer. The excited amplitude per unit voltage at the resonance frequency was calculated as about 5 µm/V. The cantilever amplitude can be detected by measuring the current between electrodes, since the admittance depends on the quality factor. We have constructed a dynamic SFM without external oscillator and detector, and successfully obtained the surface images of a sol-gel derived PZT film in the cyclic contact operation mode. The longitudinal resolution of the SFM system was 0.3 nm at a 125 Hz bandwidth.

Memory type polymer dispersed liquid crystal (PDLC) can be applied to a thermal addressing display device cell. Making use of its easy fabrication of large area display using flexible film substrate, the PDLC film can be used as reusable paper for direct-view mode display. In this study, memory type PDLC cells are prepared with an aluminum reflector deposited onto one side of the substrate and the reflection property in the PDLC cell with the reflector is clarified and compared to that without the reflector in the off-, on- and memory-states. The increase of contrast ratio and the decrease of driving voltage can be concurrently realized by decreasing the cell thickness by attaching the reflector. In addition, the reflected light in the off-state is bright and colorless due to the reflector, as compared with the weak, bluish reflected light in the cell without the reflector. Reflected light in the on-state and the memory-state are tinged with blue.

Precise measurements of temperature dependence of the Andreev reflection current for the N–I–S junctions were carried out. Au and Pb were used as N (normal metal) and S (superconducting material), respectively. The experimental results agreed with the analyses based on the Arnold theory.

We propose and demonstrate an excellent linearly frequency-swept laser diode (LD) for sensing system utilizing frequency-moduleted continuous-wave (FMCW) technique. In order to linearly sweep the optical frequency, we adopt a reference interferometer and an electric phase comparator. The interference beat signal of the reference interferometer is phase-compared with an external reference rectangular signal having a fixed frequency near the interference beat signal frequency by a lock-in amplifier. The error signal from the lock-in amplifier is fed back to the modulating signal of the injection current of the LD. Thus, a phase-locked loop composed of optical and electric circuits can be established, and the beat signal frequency is locked to the frequency of the reference signal. The optical frequency of the LD is, therefore, excellently linearly swept in time. In order to experimentally confirm the linearlity of the proposed method, we apply this light source to the FMCW reflectometry. Resultingly, the improvement of the linearity is estimated to be about 10 dB. And the theoretically limited spatial resolution of the FMCW reflectometry is achieved.

A new self-holding optical switch that consists of an optical matrix board and a precision robot is proposed. Fabrication and evaluation of 33 optical matrix boards confirm the feasibility of large-size optical switching. Suppressing deviations in the groove position will realize lower loss optical matrix boards in the near future. The apparent roughness of the groove walls can be evaluated simply and effectively by measuring return loss with an interferometric optical-time-domain reflectometer.

In this paper, we extend two-image photometric stereo method to treat a concave polyhedron, and present an iterative algorithm to remove the influence of interreflections. By the method we can obtain the shape and reflectance of a concave polyhedron with perfectly diffuse (Lambertian) and unknown constant reflectance. Both simulation and experiment show the feasibility and accuracy of the method.

This paper describes a new method to determine the 3-D position coordinates of a Lambertian surface from four shaded images acquired with an actively controlled, nearby moving point light source. The method treats both the case when the initial position of the light source is known and the case when it is unknown.

The magnitude of low frequency noise is studied in a Nb-(nanoconstrictions)-NbN system with adjustable current-voltage characteristics. We find that the magnitude of low frequency noise decreases sharply with increasing the subgap conductivity of the device. We suggest a qualitative explanation of this observation in terms of gradual build up of the nanoconstriction region by field assisted growth. The decrease of low frequency noise is related to the "cleanliness" of the system as measured by the amount of Andreev reflection-related conductivity. The scaling of the magnitude of low frequency noise with device resistance is also discussed.

In this paper, we discuss an application of range Doppler imaging to measurement of reflected wave intensity from a moving object without using an anechoic chamber. The wave intensity reflected from a metal plate moving in the horizontal direction toward the antenna is typically 40-50 dB higher than that in the case without using the plate, and the estimated radar cross sections for a metal plate and sphere show good agreement with the theoretical value. The measurement of wave absorption by the present method suggests that frequency characteristics of the observed reflection loss are in close agreement with those of the calculated loss. These results show the reliability of the present experimental system and suggest that the method is applicable to wave reflection measurement not in an anechoic chamber but in an ordinary laboratory room.

This paper discusses the effect of random errors in power meter readings by the six-port reflectometer. By means of six-port techniques, the determination of the reflection coefficient (Γ) of a divice under test is reduced to the problem of finding a common intersection of three circles in the complex plane. Since the intersection usually forms a cluster due to the effect of measurement error, the extraction of a single value from the cluster including the radical center of the three circles is required. Two types of methods are presented for determining Γ. One uses a linear solution for the radical center, and the other is a statistically based nonlinear solution. In order to improve measurement accuracy, the effect of random errors in the sidearm power meter readings and due to the influence of the q-point locations are investigated for each method. By adding a random variation of 0.5% onto each of the three port power ratios, the variance distributions of Γ over the entire area of the Smith chart are simulated for comparison of these two solutions. The three dimensional variance distribution chart reveals that only the nonlinear solution suffers a variance increase shown as a ridgelike peak along the lines of centers of the three circles. As a result of computer simulations, it is clarified that the reflectometer has the property of measurement accuracy dependence on the value of Γ. A new type of six-port model is suggested, which is unlikely to be affected by random errors in the nonlinear solution.

Wave digital filters are a class of digital filters. They are equivalent to commensurate transmission line circuits synthesized with uniform, lossless, and commensurated transmission lines. In order to extend their applications to physical wave phenomena including quantum electronics, it is necessary to consider a generalized distributed line whose velocity of energy flow has frequency characteristics. This paper discusses a generalized distributed circuit, and we obtain two types of lines, lossless and cut-off. In order to analyze these lines, we discuss signal flow graphs of steady state voltage and current. The reflection factors we obtain here are the same as that for an active power or a diagonal element of a scattering matrix, which is zero in conjugate matching. By using this reflection factor, we obtain band-pass filters synthesized with the cut-off lines. We also describe an analysis method for nonuniform line related to Riccati differential equation.