Two high output-resistance CMOS current mirrors suitable for a low-voltage operation and achieving a high output-swing are presented. They incorporate a modified regulated-cascode, which employs a current-mode amplifier. The main architecture concepts and their detailed schematic examples are discussed. SPICE simulation comparison is shown and the properties of each architecture are pointed out.

A Monte Carlo method for the passage of electrons based on a single scattering model is developed. A code based on this method is operable on personal computers, and has been applied to analyze electron behavior in a layered system consisting of Ti (an accelerator window), air, cellulose triacetate (CTA) and backing material irradiated by 300 keV electrons. The energy spectra and the angular distributions of electrons on the CTA surface as well as depth distributions of energy deposition in the CTA for various backing materials have been obtained. Some of these results are compared with experiments, and show fairly good agreement.

The state of the art of low-voltage (LV) analog circuit design techniques is reviewed, and fundamental design techniques are identified and classified as follows: 1) current-mode, 2) series-to-parallel, 3) signal range sharing, 4) dynamic bias, 5) linear bias, and 6) LV regulator. A relatively wide variety of low frequency application circuits have been developed, but future development is expected for wide-bandwidth application circuits such as a voltage-controlled-oscillator (VCO), a balanced multiplier, etc. The circuit techniques such as current-mode, signal range sharing, and dynamic bias will probably be most important for advanced future circuit designs.

We developed an eye-contact technique using a blazed half-transparent mirror (BHM), which is a micro-HM array arranged on the display surface, to make a compact eye-contact videophone. This paper describes a new BHM structure that eliminates ghosts and improves image quality. In the new BHM, the reflection and transmission areas are separated to exclude ghosts from appearing in the captured image. We evaluated the characteristics of the captured and displayed images. The results show that the contrast ratio of the captured image and the brightness of both captured and displayed images are much better than with the previous BHM.

Exact analytical solutions for the steady-state transmission and reflection characteristics of a nonlinear Fabry-Perot resonator applicable to bistable optical devices are derived. The resonator consists of a Kerr-like nonlinear film sandwiched by reflection mirrors made of a quarter-wave dielectric stack. An equivalent mirrorless model has been introduced to facilitate the analysis. For both positive and negative nonlinear coefficients, the rigorous solutions have been simply expressed in terms of Jacobian elliptic functions.

Recent progress on the ultrahigh-speed optical transmission experiments are reviewed including the ultrashort pulse generation, high-speed timing extraction, all-optical multi/demultiplexing. Also discussed are the latest 100 Gbit/s experiments and a scope to higher bit-rate, longer distance optical transmission.

An eye-contact technique using a blazed half-transparent mirror (BHM) is developed. This half-transparent mirror (HM) consists of an in-line array of many slanting micro-HMs. We fabricated a prototype system and confirmed the principle of this technique. The resolution of an image reflected by a BHM was simulated to determine how to improve the image quality and the factors degrading the resolution were clarified.

An HDTV still-picture camera that uses four PAL CCD sensors has been developed for use as a high-speed, high-resolution image reader. The CCD sensors are optically coupled to a single lens by a pyramidal mirror. Each CCD sensor reads a quarter of the image and the four quarter-images are combined into one HDTV picture. Discontinuities at the lines where the four images join can be eliminated by white- and dark-level correction and gamma correction. Moreover, smoothing processing using a weighted-mean method is performed to produce a seamless picture. With this processing the camera can consistently produce seamless pictures.

Novel circuit design techniques for CMOSFET (complementary MOS field-effet transistor)-only bias circuits, which each include a current mirror with a peaking characteristic, a current reference with a positive temperature coefficient, and a voltage reference with an optional temperature dependence, are described. An MOS Nagata current mirror is analyzed, and bias circuits like a CMOS self-biasing Nagata current reference and a CMOS self-biasing Nagata voltage reference, both of which include an MOS Nagata current mirror, are discussed. In addition, a CMOS temperature coefficient shifter, used to add an offset voltage and an optional temperature coefficient to a reference voltage, is also discussed. The CMOS Nagata voltage reference was verified with a breadboard using discrete componente and a 0.15 mV/ temperature dependence.

A wavelength-insensitive reflector is demonstrated with a fibre loop which has an asymmetry in the constituent coupler. The reflector is made by thinning one of two identical fibres. The reflected power is more than 0.6 dB (87%) over the wavelength region of 1.2-1.35 µm and 1.42-1.65 µm. The transmitted power is less than 30 dB in the 1.23-1.63 µm region and less than 40 dB at 1.3 and 1.55 µm.

We have calssified parenchymal echo patterns of cirrhotic liver into four types, according to the size of hypoechoic nodular lesions. Neural network technique has been applied to the characterization of hepatic parenchymal diseases in ultrasonic B-scan texture. We employed a multi-layer feedforward neural network utilizing the back-propagation algorithm. We carried out four kinds of pre-processings for liver parenchymal pattern in the images. We describe the examination of each performance by these pre-processing techniques. We show four results using (1) only magnitudes of FFT pre-processing, (2) both magnitudes and phase angles, (3) data normalized by the maximum value in the dataset, and (4) data normalized by variance of the dataset. Among the 4 pre-processing data treatments studied, the process combining FFT phase angles and magnitudes of FFT is found to be the most efficient.

Manipulation of Boolean functions is one of the most important techniques for implementing of VLSI logic design systems. This paper presents a fast method for generating prime-irredundant covers from Binary Decision Diagrams (BDDs), which are efficient representation of Boolean functions. Prime-irredundant covers are forms in which each cube is a prime implicant and no cube can be eliminated. This new method generates compact cube sets from BDDs directly, in contrast to the conventional cube set reduction algorithms, which commonly manipulate redundant cube sets or truth tables. Our method is based on the idea of a recursive operator, proposed by Morreale. Morreale's algorithm is also based on cube set manipulation. We found that the algorithm can be improved and rearranged to fit BDD operations efficiently. The experimental results demonstrate that our method is efficient in terms of time and space. In practical time, we can generate cube sets consisting of more than 1,000,000 literals from multi-level logic circuits which have never previously been flattened into two-level logics. Our method is more than 10 times faster than ESPRESSO in large-scale examples. It gives quasi-minimum numbers of cubes and literals. This method should find many useful applications in logic design systems.

Up to present, some automatically tunable active RC filters have been proposed for the monolithic integrated continuous-time filters. In this paper a synthesis method of monolithic active RC filters is presented, whose characteristic is hardly dependent on temperature, supply voltage and so on, theoretically. First, this paper describes a variable integrator controlled by bias current. Second, a resistor controlled current source circuit (RCCS) is also proposed, which contains the voltage controlled current source (VCCS) being identical with that used in the realization of the integrator and whose current is controlled by an external resistor. The use of this VCCS in the RCCS can completely compensate the variation of the integrator characteristics. Finally, these circuits are applied to realize a third-order elliptic low-pass filter, which is simulated on PSPICE. From the simulations, we obtain excellent results as follows: The deviation of gains in the passband due to the variation of temperature with a range of -10 to 60 is within 0.02 dB; A total harmonic distortion with a 1 Vp-p input voltage at 100 kHz is less than 0.4% when the cut-off frequency is 1 MHz and the supply voltage is 5 V.

Plasmaless etching using ClF3 gas has been investigated on nitride films with different composition. For the sputter deposited and thermally grown silicon nitride films containing no hydrogen, the etch rate increases and the activation energy decreases with increase of the composition ratio of silicon to nitrogen between 0.75 and 1.3. This fact indicates that the etching is likely to proceed through the reaction between Si and ClF3. The native oxide on the silicon-nitride films can also be removed with ClF3 gas. Ultra-violet light irradiation from a low pressure mercury lamp remarkably accelerates the removal of the native oxide and the etch rate of the thermally grown silicon-nitride films. For the plasma deposited films, the etch rate is strongly accelerate with increasing hydrogen content in the films, but the activation energy hardly depends on the bounded hydrogen in the films, consistent with the results for Si etching.

Fourier holographic image storage and reconstruction using BaTiO3 photorefractive crystal waveguide is investigated. The phase conjugation technique, which compensates image distortion caused by modal phase dispersion, successfully retores images stored in a test BaTiO3 crystal waveguide.

A new set of self-consistent linear equations is presented for the analysis of the startup characteristics of gyrotron oscillators with an open cavity consisting of weakly irregular waveguides. Numerical results on frequency detuning and oscillation starting current for a whispering-gallery-mode gyrotron are described in which these equations were utilized. Experiments for making a check on the effectiveness of the derived equations showed that they well express the operation of gyrotrons in comparison with the linear theory using an empty cavity field as the wave field.