Abstract: The implementation of large-valued floating resistive elements using MOS transistors in subthreshold region is addressed. The application of these elements to bias wideband AC coupled amplifiers is discussed. Simple schemes to generate the gate control voltages for the MOS transistors implementing large resistors so that they remain in high resistive state with large signal variations are discussed. Experimental results of a test chip prototype in 0.5-µm CMOS technology are presented that verify the proposed technique.

Abstract: This paper reports on the measured dc characteristics of a SiC JFET device from room temperature up to 450°C in order to evaluate the device's capability for high-temperature operation. The authors packaged SiC JFET bare die into a dedicated high-temperature package to be able to perform experiments under extremely high ambient temperatures. The experimental results show that the device can operate at 450°C, which is impossible for conventional Si devices, but the current capability of the SiC JFET diminishes with rising temperatures. For example, the saturation current becomes 20% at 450°C with respect to the value at the room temperature.

Abstract: We have developed a system of compositing three-dimensional (3D) video images based on the depth information of the objects. The system consists of the Axi-Vision Camera that can measure object distance in real time and an arithmetic image processor that can synthesize video images according to the depth information. The paper demonstrates how to three-dimensionally synthesize such a scene as an array of computer-generated characters moving around a standing person in real time. The feasibility of using such a signal processor to create realistic TV programs in a broadcasting station has been studied.

Abstract: Two novel configurations of second-order sinusoidal oscillators have been presented which employ only unity-gain voltage followers and current followers as active elements. The workability of the new circuits has been demonstrated by the SPICE simulations of their CMOS-implementable versions.

Abstract: Recently, the authors introduced two new second-order single-resistance-controlled oscillators (SRCO) employing four/three unity-gain cells (unity-gain voltage followers and unity-gain current followers). In this communication, a novel family of SRCOs has been presented which employ a reduced number of (only two) unity-gain cells as active elements. The workability of the new circuits has been confirmed by the SPICE simulations of their CMOS-implementable versions.

Abstract: Fingerprint matching is one of the most important problems in Fingerprint Identification System (AFIS). In this paper a new method of the reference point alignment has been presented. A new approach of reference point localization is based on so-called identification masks which have been composed on the basis of analysis of biometric characteristic of human finger. Construction of such masks has been presented.Experiments show that our approach locates a unique reference point with high accuracy for all types of fingerprints. Generally, fingerprint matching consists with three steps: core (reference) point detection, filter the image using a bank Gabor filters, and comparison with imprint pattern. It seems, that today, the Gabor filtering gives the best results in fingerprint recognition. The proposed method was evaluated and tested on various fingerprint images, included in the FVC2000 fingerprint database. Performed results with representative investigations have been compared.

Abstract: We designed a special CMOS circuit for reaction-diffusion computers that accepts optical inputs in parallel and generates excitable spatial waves on a chip surface. We demonstrated the spatiotemporal properties of the proposed circuits by fabricated LSIs.

Abstract: Affine arithmetic (AA) is a variant of interval arithmetic. In AA, it is difficult to realize the efficient nonlinear binomial operations. The purpose of this paper is to propose a new dividing method which consists of a reciprocal and the best multiplication. And the performances of the new method and the conventional method are compared through some numerical examples.

Abstract: We propose a monolithic external-cavity vertical-cavity surface emitting laser (VCSEL) for achieving ultra-high speed direct modulation beyond the limit of a relaxation oscillation frequency. We present the modeling of small-signal and large signal modulation characteristics of VCSELs with optical feedback. It is predicted that a 3 dB-modulation bandwidth can be increased by 50% with optimizing an external cavity length. Also, better eye opening can be expected in 40Gbps direct modulation.

Abstract: We propose and demonstrate the Coherent Optical Multiple-Input Multiple-Output (COMIMO) communication technique. In analogy to the spatial diversity in wireless communication, the concept exploits the modal diversity, inherent in a multi-mode fiber (MMF), to transmit independent data channels through a single fiber without the need for wavelength division multiplexing. Central to the MIMO concept is the requirement for sufficient modal diversity in the fiber. The coherent-optics implementation is the key as it ensures that the diversity requirement is met for practically any fiber length and at any data rate. A 2x2 proof-of-concept COMIMO system is experimentally demonstrated.

Abstract: To improve analog design automation (ADA) of electronic circuits, an interactive system for symbolic analysis called SIASCA is introduced. SIASCA includes schematic capture of a more general class of analog circuits, namely: operational transconductance amplifiers and current conveyors. The options of analysis are focused on calculating simplified symbolic expressions (SEs), representing the dominant behavior of a circuit, for AC and noise analysis. To minimize complexity in manipulating SEs, all active devices are modeled at different levels of abstraction by using nullors. Several examples demonstrate the suitability and usefulness of SIASCA to be used within ADA environments.

Abstract: An alternative formulation for a frequency dependent (FD) ADI-FDTD method is proposed, based on an electric flux field D tridiagonal matrix rather than an electric field matrix. The procedure for D source excitation is explained. Results show that the accuracy of the method is unaffected by the inclusion of frequency dependency in the model, compared with FD-FDTD.

Abstract: We demonstrate a multi-user, 10Gb/s spectrally phase coded O-CDMA system with hybrid chip and slot-level timing coordination utilizing low power nonlinear processing. A new double Hadamard coding scheme is demonstrated to enable both chip-level timing coordination and full interference suppression without the need for synchronous detection.

Abstract: We demonstrate a silicon Raman laser and report observation of simultaneous lasing at 1675nm and parametric Raman emission at 1540nm. The laser is pumped with 1540nm pulses and has a threshold at 9W peak pulse power.

Abstract: Moments are widely-used feature extractors due to their superior discriminatory power and geometrical invariance. Unfortunately, moments suffer heavy computational load and result long time spending. In viewing of the problem, we proposed a new technique in using moments- apply moments on wavelet subband. In this study, pseudo Zernike moments are selected as feature extractors due to its enhanced feature representation capability. Implementation of moments on wavelet subband affords advantages of performing local-to-global analysis and decomposing image into lower resolution. Experimental results show that this hybrid achieves computational time reduction of 36.23% with enhanced authentication performance.

Abstract: A φ0.8mm micro-solid propellant rocket array thruster for simple attitude control of a 10kg class micro-spacecraft was tested in vacuum. The micro-thruster uses boron/potassium nitrate propellant (NAB), because NAB has ignition temperature as low as 500°C, and easily start to burn in vacuum. For a half of the rockets, an ignition aid (RK) was also loaded. Ignition was succeeded in vacuum with NAB + RK and NAB. The maximum impulse thrust of 4.6 × 10-4 Ns, which is approximately a half of our requirement, was obtained with NAB. Compared to NAB, NAB + RK generated lower impulse thrust. The success rate of ignition was as low as 30%, although RK was used. These results suggest that RK has no benefit for the ignition of NAB, and other kinds of ignition aid should be found.

Abstract: A high-sensitive CMOS photosensor based on a pulse frequency modulation (PFM) scheme is presented. We propose and demonstrate the high-sensitive PFM photosensor, whose output frequency is proportionate to the incident light intensity, that utilizes MOS interface-trap charge pumping (ITCP) as a frequency-controlled ultra-low current. The proposed pixel sensor consists of only 4 transistors: a transistor as an ultra-low current source; a sense amplifier transistor; a selection transistor; and, a reset transistor. The prototype device is fabricated using 0.6-µm standard CMOS technology. High sensitivity 4.0 × 105Hz/(W·m-2), which is larger than two orders of magnitude compared to previous works, was obtained.

Abstract: In this article, the new multi-polarity helix transform for ternary logic functions has been introduced. In addition, an extended dual polarity property that had been used to optimize Kronecker and quaternary Fixed-Polarity Reed-Muller (FPRM) expressions has been applied to generate efficiently the multi-polarity helix transform over GF(3). The experimental results for the transform are compared with the well known ternary Reed-Muller transform and it was found that the helix transform is quite efficient in terms of non-zero spectral coefficients and corresponding memory storage.

Abstract: Asymmetric parallel-coupled coplanar waveguide (CPW) is originally characterized here as an equivalent unified K-inverter network. On a basis of our developed self-calibrated method of moments (MoM), the relevant network parameters are extracted to explicitly demonstrate the frequency-dependent coupling behavior with the 1st zero coupling at the λ/2 length of overlapped section. By differentiating the coupled spaces and overlapped lengths, the two CPW coupling structures are dissimilarly constructed and utilized as the input/output excitation of a λ/4 CPW bandpass filter. Through allocating the two unequal zeros towards the spurious harmonic around 3λ/4, an improved two-stage λ/4 CPW filter is designed at 5.0GHz. Optimized results achieve broad rejection band, ranging from 5.8GHz beyond 18.0GHz, as verified by the ADS simulation.

Abstract: A highly efficient and low noise gain-clamped long-wavelength-band erbium-doped fiber amplifier (L-band EDFA) is demonstrated using a ring laser in double-pass system. The broadband fiber Bragg grating (FBG) operating at L-band region is used to retro-pass the test signal into the system for enhanced gain. A length of forward pumped EDF is incorporated in front of the double-pass amplifier to achieve a low noise figure. The gain clamping is achieved by routing the backward ASE into the feedback loop to create ring laser. The gain is clamped at 18.6dB from -40 to -8dBm with gain variation of less than ±0.1dB and a noise figure of less than 6dB.

Abstract: Pseudomorphic In0.25Al0.75P/In0.75Ga0.25As high electron mobility transistors (HEMTs) were fabricated to investigate the short-channel effect in the sub-0.1-µm gate-length region. Employing a thin Schottky barrier and a thin channel layer structure enabled us to suppress the short-channel effect in short-gate HEMTs, and a high-performance 47-nm-gate HEMT with a 423-GHz current gain cutoff frequency was achieved. The present results show the possibility of the practical use of pseudomorphic HEMTs with a scaled-down structure for various applications, such as ultra-high-speed digital circuits and millimeter-wave communications/observations.

Abstract: I fabricated an inverted-mesa quartz resonator having a 2.2-µm-thick vibrating area by wet etching. The resonator excited a 622-MHz-fundamental thickness vibration. By selecting a 30-nm-thick gold electrode, the temperature-frequency characteristics exhibited a cubic curve with a frequency deviation of 26ppm over a range of temperature from -40°C to +85°C. Furthermore, the resonator was miniaturized to reduce loss caused by the film resistance, and to decrease the parallel capacitance. The series resistance at the noninductive resonance frequency was 33ohm and the parallel capacitance was 0.96pF. Therefore, the fundamental thickness vibration had a wide inductive region.

Abstract: The major drawback of the fractal image compression is the high encoding complexity to find the best match between a range block and a large pool of domain blocks. This paper presents a fast fractal-encoding algorithm based on the law of cosines. The number of domain blocks searched to find the best match for each range block is safely reduced by eliminating the ineligible domain blocks using the law of cosines. Simulation results show that the proposed algorithm can produce a completely identical fractal code to that of the exhaustive search in reduced time.

Abstract: An image contrast enhancement algorithms for BDCT (Block Discrete Cosine Transform) based compressed images is presented. Contrast enhancement is achieved by modifying the quantized DCT coefficients based on a contrast measure defined within the DCT domain. The performance is compared with other methods and better visual quality is obtained.

Abstract: This paper describes a new association of a high-Q pseudo 8-path switched-capacitor (S-C) bandpass filter and its command circuit made up by a ring VCO with `XOR' gates. The proposed circuit presents the possibility of tuning over a radio-frequency (RF) broadband allowing to sweep different channels with a high quality factor. Designed with CMOS process (0.35µm, for instance), this circuit is intended to replace the surface acoustic wave (SAW) filters in modern wireless receivers. Measurements carried out on a circuit demonstrator show a tunable center frequency range of 200MHz [300-500MHz], with a quality factor higher than 300.

Abstract: The thermo dynamical stability of a boron atom at the Si/SiO2 interface was studied by using ab initio calculation to investigate a mechanism of boron pile-up at the interface during thermal annealing. The B atom is stable in bulk Si site of the interface without any interface defect, which contradicts the experimental observations. By introducing an oxygen vacancy at the interface, the mechanism of B segregation into SiO2 layer at the atomic scale was verified.

Abstract: We carried out the evaluation of the thermal cross-talk in a 1.2µm band densely packed vertical cavity surface emitting laser (VCSEL) array for the first time. The spacing of neighboring elements is as small as 20µm. We measured the wavelength shift for different integrated elements, which gives us the temperature change, as a function of the distance from a heat source. We also carried out three-dimensional thermal modeling for the array, which shows good agreement with the experiment. It is predicted that the lasing wavelength of the array is affected by a thermal cross-talk when adjacent elements are operated at the same time.

Abstract: A small, low-cost FM-CW demonstrator system has been designed to investigate the feasibility of the application of FM-CW SAR in the field of airborne earth observation. A Ka-band backscatter model function and an algorithm for measurement of the wind vector over the water surface by this demonstrator system in the scatterometer mode have been developed. The principle considered, backscatter model and measuring algorithm proposed can be used for creating an airborne radar system for operational measurement of the sea roughness characteristics and for safe landing of an amphibious airplane on water, in particular under search and rescue missions in coastal areas.

Abstract: An annealing study of the AlGaN/GaN 2DEG structure for HEMTs with or without SiN surface passivation films was conducted with the AlGaN layer thickness dependence taken into consideration. Without SiN, the sheet resistance of the samples with thin AlGaN layers increased significantly upon annealing at 620 and 800°C. In contrast, samples with SiN were thermally stable after annealing at up to 800°C even when the AlGaN layer was as thin as 152A. TEM observations revealed that neither surface roughness nor interfacial diffusion at the SiN/AlGaN interface occurred due to annealing. The SiN layer is very effective for passivating an AlGaN surface and improving the thermal stability of a thin-AlGaN 2DEG channel.