A network for the detection of an approaching object with simple-shape recognition is proposed based on lower animal vision. The locust can detect an approaching object through a simple process in the descending contralateral movement detector (DCMD) in the locust brain, by which the approach velocity and direction of the object is determined. The frog can recognize simple shapes through a simple process in the tectum and thalamus in the frog brain. The proposed network is constructed of simple analog complementary metal oxide semiconductor (CMOS) circuits. The integrated circuit of the proposed network is fabricated with the 1.2 µm CMOS process. Measured results for the proposed circuit indicate that the approach velocity and direction of an object can be detected by the output current of the analog circuit based on the DCMD response. The shape of moving objects having simple shapes, such as circles, squares, triangles and rectangles, was recognized using the proposed frog-visual-system-based circuit.

In this letter, my proposals for a Floating node voltage-controlled Variable Resistor circuit (FVR) are based upon its advantages as linear and compact. The performance of the proposed circuit was confirmed by PSpice simulation. The simulation results are reported in this letter.

A two-dimensional network for motion detection constructed of simple analog circuits was proposed and designed based on the frog visual system. In the frog visual system, the two-dimensional motion of a moving object can be detected by performing simple information processing in the tectum and thalamus of the frog brain. The measured results of the test chip fabricated by a 1.2 µm complementary metal oxide semiconductor (CMOS) process confirmed the correct operation of the basic circuits in the network. The results obtained with the simulation program with integrated circuit emphasis (SPICE) showed that the proposed network can detect the motion direction and velocity of a moving object. Thus, a chip for two-dimensional motion detection was realized using the proposed network.

A simple self-biased receiver system with a dual branch architecture consisting of a low-power consumption receiver and a rectenna is introduced. The system is efficiently integrated with a dual-fed circular sector antenna with harmonic rejection characteristics without a BPF. The receiver portion is designed by utilizing a low-noise amplifier (LNA) with low power consumption and a self-heterodyne mixer, while the rectenna achieves high conversion efficiency up to 80%, thanks to the harmonic rejection of the circular sector antenna. The rectified DC power from the rectenna is applied for a bias of the receiver without any external bias. Simultaneously, an ASK digital signal demodulation without an extra power supply are implemented successfully.

To support international medical collaboration activities carried out among Japan, Sri Lanka and other countries in Asia, we have been developing a collaboration system, which incorporates synchronous and asynchronous collaboration paradigms through network-effective persistent information sharing. The designed system facilitates synchronous collaborative work on maxillo-facial cases through real-time high-quality image delivery and by bringing the system database objects to a shared-workspace. The asynchronous activities are supported through a web based collaborative environment that enables both activity-centric and object-centric navigation of collaboration contents incorporated with email notifications of the system updates. Multimedia records of synchronous sessions are posted to the system database for later reviewing. Geographically dispersed groups experiencing different scales of network heterogeneities are served by a distributed application level multicast overlay and an adaptive multimedia delivery mechanism. The designed collaboration system also features several useful collaboration tools, user friendly GUI and ubiquitous connectivity.

This paper presents a frequency-controllable image rejection mixer in heterodyne architecture for 2 GHz applications based on TSMC 0.18 µm CMOS technology. The designed mixer uses a notch filter to suppress the image signal and allows precise tuning the image frequencies. An image rejection of 20-70 dB is obtained in a 200 MHz of bandwidth. The simulation results show single-side band (SSB) NF is improved 3.7 dB, the voltage conversion gain of 14.7 dB, improved by more than 4 dB. The circuit operates at the supply voltage of 1.8 V, and dissipates 11.34 mW.

This paper presents a high performance wideband CMOS direct down-conversion mixer for UWB based on 0.18 µm CMOS technology. The proposed mixer uses the current bleeding technique and an extra resonant inductor to improve the conversion gain, noise figure (NF) and linearity. Also, with an extra inductor and the careful choosing of transistor sizes, the mixer has a very low flicker noise. The shunt resistor matching is applied to have a 528 MHz bandwidth matching at 50 Ohm. The simulation results show the voltage conversion gain of 20.5 dB, the double-side band NF of 5.6 dB. Two-tone test result indicates 11.25 dBm of IIP3 and higher than 70 dBm of IIP2. The circuit operates at the supply voltage of 1.8 V, and dissipates 11.5 mW.

A transition between an NRD guide, suitable for construction of high performance millimeter-wave integrated circuits, and a microstrip line, being used to mount semiconductor devices such as HEMT, HBT, and MMIC, was developed at 60 GHz. The main emphasis was placed on the manner of field matching between the NRD guide and the microstrip line. We propose adoption of this a new transition structure employing a vertical strip line, which can be easily coupled to the NRD guide, and a coaxial line connected to the microstrip line. Moreover, we applied a packaging structure with a choke circuit for the microstrip line to prevent undesired leakage between the NRD guide and the microstrip line. The insertion loss of the fabricated transition was measured to be less than 0.5 dB in the bandwidth of 3 GHz at a center frequency of 60.5 GHz. The transition was applied to MMIC amplifier integration in the NRD guide at 60 GHz. The forward and reverse gains were measured to be 15 dB and -20 dB, respectively, at 60 GHz.

A higher mode tri-plate strip transmission line, in which the first higher mode propagates, was developed to realize mass production of millimeter-wave integrated circuits for application in intelligent transport systems, and its transmission characteristics were investigated. The design diagram of this guided mode was determined and a higher mode tri-plate strip transmission line was fabricated at 30 GHz. The dispersion curve was found to be similar to that of a rectangular waveguide and a low transmission loss of less than 10 dB/m was obtained. For construction of some functional devices, two types of basic reactance components, such as a gap and a slot, were expressed by equivalent circuits. The former was expressed by capacitive parameters, and the latter was expressed by an ideal transformer with inductive parameters. The gap-coupled circuit was successfully employed for a 3-pole 0.1 dB Chebyshev ripple band-pass filter with a small excess insertion loss of less than 1 dB at a center frequency of 32 GHz, as well as no spurious response in a bandwidth from 26.5 GHz to 40 GHz. The slot element acted as a matching circuit and a suppressor of the lowest mode, which is the TEM mode in the tri-plate strip transmission line. Moreover, this element was applied to a mode transformer between the lowest mode and the first higher mode.

In this letter, we propose a sample and hold circuit (S/H circuit) with the clock boost technique and the input signal tracking technique. The proposed circuit block generates the clock with the amplitude of VDD + vin, and the clock is used to control the MOS switch. By applying this circuit to a S/H circuit, we can deal with the rail-to-rail signal with maintaining low distortion. Furthermore, the hold error caused by the charge injection and the clock feedthrough can be also reduced by using the dummy switch. The Star-HSPICE simulation results are reported in this letter.

The most obvious architectural solution for high-speed fuzzy inference is to exploit temporal parallelism and spatial parallelism inherited in a fuzzy inference execution. However, in fact, the active rules in each fuzzy inference execution are often only a small part of the total rules. In this paper, we present a new architecture that uses less hardware resources by discarding non-active rules in the earlier pipeline stage. Compared with previous work, implementation data show that the proposed architecture achieves very good results in terms of the inference speed and the chip area.

The performance of integrated segmentation and recognition of handwritten numeral strings relies on the classification accuracy and the non-character resistance of the underlying character classifier, which is variable depending on the techniques of pattern normalization, feature extraction, and classifier structure. In this paper, we evaluate the effects of 12 normalization functions and four selected feature types on numeral string recognition. Slant correction (deslant) is combined with the normalization functions and features so as to create 96 feature vectors, which are classified using two classifier structures. In experiments on numeral string images of the NIST Special Database 19, the classifiers have yielded very high string recognition accuracies. We show the superiority of moment normalization with adaptive aspect ratio mapping and the gradient direction feature, and observed that slant correction is beneficial to string recognition when combined with good normalization methods.

This paper presents a systematic methodology for the system-level assessment of signal integrity and electromagnetic compatibility effects in high-speed communication and information systems. The proposed modeling strategy is illustrated via a case study consisting of a critical coupled net of a complex system. Three main methodologies are employed for the construction of accurate and efficient macromodels for each of the sub-structures typically found along the signal propagation paths, i.e. drivers/receivers, transmission-line interconnects, and interconnects with a complex 3D geometry such as vias and connectors. The resulting macromodels are cast in a common form, enabling the use of either SPICE-like circuit solvers or VHDL-AMS equation-based solvers for system-level EMC predictions.

An ultra-small (0.3-mm0.3-mm0.06-mm) radio frequency identification chip called the µ-chip has been developed for use in a wide range of individual recognition applications. The chip is designed to be thin enough to be applied to paper and paper-like media that are widely used in retailing to create certificates with monetary value, as well as to token-type devices. The µ-chip has been designed and fabricated using 0.18-µm standard CMOS technology. This ultra-small RFID chip also has a low-cost oriented device structure of a double-surface electrode to simplify the process of connecting the antenna and chip. The measured characteristics of the prototype chip are presented, demonstrating the capability of the new chip as an RFID device.

A technique to control the radiation pattern of an NRD-guide-compatible pyramidal horn antenna, which consists of a tapered dielectric rod inserted into the horn, was developed for multiple access LAN applications at 60 GHz. By using this simple technique, the half-power beamwidth can be controlled from 11to 40.

In this letter, two kinds of MOS operational transconductance amplifiers (OTAs) based on combiners are presented. Each OTA has the following advantages; one of the proposed OTAs (OTA-1) can be operated at low supply voltage and the other OTA (OTA-2) has wide bandwidth. Through HSPICE simulations with a standard 0.35 µm CMOS device parameters, the operation under the supply voltage of 1.5 V for OTA-1 and the -3 dB bandwidth of several gigahertz for OTA-2 are confirmed.

A feedforward-based active shielding technique for digital noise suppression is more preferred for its capability of reducing the noise on the entire area inside the guard ring. In order to compensate for the variation of substrate parameters, an automatic control scheme to tune the gain of the active shield circuit is proposed. Simulation results show the effectiveness of the proposed system in reducing the digital noise regardless of circuit layout. Simulation results also show that noise suppression improvement from passive guard ring to active shield with tuning is 20 dB or one tenth while that from active shield without tuning to active shield with tuning is 12 dB.

We demonstrated the transmission over 80 km at 10 Gb/s by using the amplifier and electroabsorption-modulator integrated laser diode. Tilt-facet antireflection window is implemented, inside of which a monitor photodiode is monolithically integrated for accurate power regulation. To better control the amplifier-input power and to reduce the feedback of the amplified spontaneous emission, an attenuator is incorporated by means of the inner-window. By amplifying the modulated signal and compensating modulator-chirp by gain-saturation in the amplifier, high power optical transmission is achieved from a device with -10 dB attenuation at total laser and amplifier currents of 200 mA.

System capacity of a wireless system can be improved greatly by using variable rate transmission. Assuming a low-rate and wide-coverage signaling-only wireless network, in this paper we evaluate, analytically and numerically, the extent of this improvement for various schemes with variable transmission rates. We considered log-normal shadowing as well as the effect of Rayleigh fading. Simulation results show close proximity with the analytical predictions.

The recent progress in the field of Ti:Er:LiNbO3 waveguide lasers with emission wavelengths in the range 1530 nm < λ < 1603 nm is reviewed. After a short discussion of the relevant fabrication methods concepts and properties of different types of lasers with grating resonator, acoustooptically tunable Fabry Perot type lasers and new ring laser structures are presented.