In order to provide a low profile wire antenna for mobile communication, we have developed a new type of the transmission line type antenna, which we call a Modified Transmission Line Antenna (MTLA). Analysis of a certain type of the modified transmission line antenna has revealed that the input impedance and the gain can be determined independently by appropriately choosing antenna configuration. In this paper, we first explain the fundamental characteristics of the modified transmission line antenna. We then introduce two types of MTLA, i. e. a zigzag MTLA and a double MTLA, for practical application of the MTLA to mobile communication. Their characteristics are also discussed theoretically and experimentally.

A 1/2 frequency divider using resonant-tunneling hot electron transistors (RHETs) has been proposed and demonstrated. The circuit make the best use of negative differential conductance, a feature of RHETs, and contains one half transistors than used in conventional circuits. The RHETs were fabricated using self-aligned InGaAs RHETs and WSiN thin-film resistors on a single chip. The RHETs have an i-InGaAlAs/i-InGaAs collector barrier that improves the current gain at low collector-base voltages. Circuit operation was confirmed at 77 K.

In this paper an approach to formal specification and verification of ISDN services in LOTOS is presented. As for specification, it is shown that LOTOS can be effectively applied to describe different levels of ISDN service specifications. At the higher level, only the external behaviour of the network is specified. On the other hand, at the lower level, specifications include the behaviour of network components such as switching systems, where each switching system can be specified independently of each other. Such specification style, proves suitable for verification of specifications by using the concepts of the simulation relation.

This paper describes on the transmission properties of the superconducting coplanar waveguide on LiNbO3 (LN) substrates, fabricated by YBa2Cu3Oy (YBCO) superconducting films. The films have been prepared by the reactive co-evaporation method and patterned by a wet etching process. The surface resistance of the obtained film was 0.04 Ω at 18 GHz and 77 K. It was confirmed from X-ray diffraction (XRD) that these films were highly oriented to the direction of c-axis without a secondary phase. The microwave transmission properties of these YBCO coplanar waveguides were investigated at frequencies up to 20 GHz and compared with that of the aluminum coplanar waveguide. The characteristic impedances of both coplanar waveguides were designed to be 50 Ω. It was found that the attenuation constants of these samples at 77 K were less than that of the aluminum coplanar waveguide for frequencies below 18 GHz.

This paper describes the structure and properties of superconductive small antennas with thin-film matching circuits. These circuits make it possible to realize small antennas, 38 mm20 mm16 mm in size. This is one quarter the length of our previously reported ceramic antennas. The actual gain of this antennas was -4.5 dBi at 470 MHz. This value is 5.5 dB higher than that of Cu antennas with exactly the same structure.

Fast wavelet transform is presented for realtime processing of wavelet transforms. A processor for the fast wavelet transform is of the frequency sampling structure in architectural level. The fast wavelet transform owes its parallelism both to the frequency sampling structure and parallel tapping of a series of delay elements. Computational burden of the fast transform is hence independent of specific scale values in wavelets and the parallel processing of the fast transform is readily implemented for real-time applications. This point is quite different from the computation of wavelet transforms by convolution. We applied the fast wavelet transform to detecting detonation in a vehicle engine for precise real-time control of ignition advancement. The prototype wavelet for this experiment was the Gaussian wavelet (i.e. Gabor function) which is known to have the least spread both in time and in frequency. The number of complex multiplications needed to compute the fast wavelet transform over 51 scales is 714 in this experiment, which is less than one tenth of that required for the convolution method. Experimental results have shown that detonation is successfully detected from the acoustic vibration signal picked up by a single knock sensor embedded in the outer wall of a V/8 engine and is discriminated from other environmental mechanical vibrations.

In this letter, a generalized syndrome polynomial is proposed from which several decoding key-equations for Reed-Solomon codes can be derived systematically. These equations are always solved by the extended Euclidean algorithm.

This paper proposes a hierarchical Digital Signal Processor (DSP) Code Generator VIRGO for large scale general signal processing algorithms. Hierarchical structured Vectorized Signal Flow Graph (V-SFG) description is used as input specifications. Ths DSP independent optimization procedure for both the program size and the execution time is performed each module by each hierarchically with regard to operation order, memory assignment and register allocation. The efficient code generation is demonstrated by comparing both instruction steps and dynamic steps of a practical ADPCM encoder/decoder with a conventional method.

In this paper we examine the architectural and operational design issues of a practical network management system using the Simple Network Management Protocol (SNMP) in the context of a large-scale OSI-based campus-network TAINS. Various design aspects are examined and the importance of time-management is elicited. In the proposed design, intelligent, time-synchronised agents are deployed to collect information about the network segments to which they are attached. The manager talks to the agents and gathers relevant network information. This information is used by the expert network manager, in conjunction with a network knowledge base (NKB) and a management information knowledge base (MIKB) , to reconstruct the overall network-traffic characteristic, to evaluate the status of the network and to take/suggest some action. This model is particularly useful in networks where some global control, monitoring and management is desired and installing agents on all elements, connected to the network, is impossible. The use of time labels and narrow time windows enables the manager to obtain a reasonably accurate picture of the network status. The introduction of time-labelled composite objects in the Management Information Base (MIB) provides a means of reducing the load of management-related traffic on the network. The MIKB containing a logical description of the behaviour of the managed objects defined in the MIB, drives the expert system and provides the knowledge of general nature that a human expert has about networks. The proposed MIKB concept provides a very convenient schema for building the knowledge base in an expert network management system. Further since the MIKB is MIB-specific, it can be used in network management systems for managing similar MIB's.

In this paper the three dimensional (3-D) effect on CMOS latch-up is modeled using a graphical technique based on the fundamental principle of "charge neutrality or its current continuity equivalent" in the base region of parasitic transistors involved in latch-up. The graphical generation of the complete latch-up I-V characteristic requires as an input the SPICE parameters of the relevant bipolar and MOS transistors, the values of shunt resistances and the reverse current-voltage characteristic of the well-substrate junction. The infiuence of the MOS transistor shunting the parasitic bipolar transistors has received special attention. The nonideal scaling of the parasitic resistances has been observed to be the most crucial parameter determining the 3-D nature of the device. The proposed model is validated with test-structures fabricated in 2 µm bulk CMOS technology at and above room temperature. SAFE space map is constructed with width W as a parameter.

This study is concerned with modeling and analyzing a nonlinear elastomer impact phenomenon when a mass experiences a collision with the contact pad mounted on the underlying linear dynamic structure. The contact pad which consists of the viscoelastic elastomer is modeled here by a nonlinear contact stiffness and nonlinear contact damper. The underlying dynamic structure is measured by a Fourier spectral analyzer and its analytical form is utilized in modeling and analyzing the whole dynamic impact problem. The impact force profiles are predicted and analyzed in terms of pulse duration, time-to-peak force, and peak force. Finally, the damping mechanism and its hysteresis phenomena are also discussed.

This paper describes the properties of non-dispersive and dispersive delay lines fabricated using EuBaCuO superconducting films. The 24 cm long stripline non-dispersive delay line showed a very low loss of 0.3 dB/nsec at 77 K and 10 GHz, and no dispersion at a delay time of 2.3 nsec at frequencies below 20 GHz. The 14 cm long microstrip dispersive delay line with modal dispersion exhibited a relative delay time of approximately 120 psec in the 118 GHz frequency range. The 26 cm long stripline dispersive delay line with structural dispersion due to coupling provided a relative delay time of 230 psec in the above frequency range and roughly the same loss as a non-dispersive delay line.

This paper proposes a high resolution and fast frequency settling PLL synthesizer for frequency hopping radio communication equipment. The proposed synthesizer enables the carrier frequency to be changed within the duration of a burst signal and yields higher frequency resolution than the reference signal frequency. To reduce frequency settling time without degradation of frequency resolution and phase noise, this paper proposes a new phase and frequency preset (PEP) PLL synthesizer which employs a digital phase accumulator to generate high resolution reference signal. Experimental results show that the settling time of a prototype synthesizer is less than 300µs while spurious signals are suppressed by more than 55 dB. In comparison with conventional PLL synthesizers, the frequency settling time is reduced by 80%. Furthermore, the higher frequency resolution than the reference signal is successfully demonstrated. Therefore, the proposed PFP PLL synthesizer with the digital reference signal can achieve the output signal with high frequency resolution less than 1Hz.

Weather conditions affect the performance of satellite broadcasting receiving systems. For example, snow accretion on antennas degrades G/T seriously because it reduces received signal power and also can increase antenna noise. We need a continuous measurement of G/T to evaluate the effect of the weather conditions to the satellite broadcasting receiving systems. However, a conventional method cannot perform the continuous measurement because the antenna under test must be oriented in a specific direction (to the zenith) to obtain a noise level in a satellite broadcasting channel. This paper presents the continuous measurement of G/T for the satellite broadcasting receiving systems. We describe details of the measurement method. In our measurement system, a standard antenna is placed at the inside of a room in order to prevent the weather conditions from affecting the gain of the standard antenna. The power flux density at the inside of the room is different from that at the outside where the antennas under test are placed. Employing the effective gain of the standard antenna, we take the difference of the power flux density into account. Moreover, we propose a method to estimate the noise level in the satellite broadcasting channel from the values at the outside of the channel, and clarify the accuracy of the noise estimation. Then, we show measurement results of the G/T values for several receiving systems. From these results, we show that the G/T measurement system has high precision. Also, from the specifications of the antenna gain and typical values of the noise figure, it is expected that the measurement system has a sufficient accuracy.

Low temperature experiments have been made to demonstrate the operation of LiNbO3 optical modulator with superconducting electrodes. The operation of the modulator for applied dc signals as well as microwave signals in the frequency range between 8 GHz and 12 GHz has been observed at temparatures as low as 4.2 K. The present results indicate a possibility of realizing high performance LiNbO3 optical modulators employing superconducting electrodes.

Among the many fabrication methods for oxide superconductor films, metal organic chemical vapor deposition (MOCVD) is particularly suitable for industrial application because of its mass productivity and the low growth temperature. Therefore we have studied this technique using the horizontal cold wall furnace type MOCVD method to obtain high quality superconducting films. As the result, we have succeeded in fabricating YBa2Cu3Oy films which have high critical temperatures (over 80 K) under substrate temperatures as low as 700 without post-annealing. But, in the course of our experiments, it was found that the thicknesses of YBa2Cu3Oy films fabricated by MOCVD were not uniform. The cause of this non-uniformity is believed to be that the deposition rate exponentially falls off along the flow direction because of the decrease of the source gas concentration through the reaction. In this paper, this non-uniformity is analytically studied. It is shown that the deposition rate decrease can be controlled with a tapered inner tube, and that these theoretical results are in good agreement with the results of experiment. In addition, it is indicated that the superconducting property of the films has less dependence on substrate position as a result of the tapered inner tube.

As the size and complexity of network increases, the distributed systems management (DSM) will be vital in order to improve the availability of network management, to reduce the complexity of network operations, and to provide the high reliability. In this paper, we (1) describe general requirements required for systems management in distributed environment, (2) introduce the basic structure of distributed network management system (DNMS) for efficient network management, and also especially illustrate the concrete design of system management application process which is an important element among them, (3) propose the connectionless CMIP to accomplish for effectively managing the distributed management system, and indicate its efficiency; this protocol is available to manage dynamically changing DSM environment, to negotiate among the managing systems, to handle the dynamic informations etc. Finally, (4) the behavior and software structure of a suggested management system during negotiation to execute the received request for implementation are presented.

This letter proposes an active reflector for calibrating a synthetic aperture radar (SAR), in which the frequency of a received SAR signal is shifted by a certain amount and then it is retransmitted to the SAR. The frequency shift causes a shift of the reflector SAR image in an azimuth direction relative to its background. This function would allow to enhance a signal-to-clutter ratio of the reflector image by moving it onto a radiometrically dark background, and hence it would be of value for SAR calibration even in a narrow test site. The theory, design and development are described briefly.

This paper proposes a next-generation narrow-band ISDN (N-ISDN), including a suitable network and network node architecture. The proposed N-ISDN allows every subscriber to use H0/HI-class calls as easily as present telephone calls, and could rapidly expand ISDN services to all the subscribers of a public network. The present status of ISDN is first analyzed then the need for popularization of H0/HI-call services is discussed. The proposed key technologies to popularize HO/HI services are (1) on-chip integration of ISDN switching systems, (2) distribution of small on-chip switching systems over the subscriber switching area, (3) H0-based trunk circuit networks using H0 on-chip switching systems and (4) efficient and flexible call management for 64-kb/s basic-class calls. An estimation of hardware volume of switching nodes is used to show that the proposed architecture is more economical than other possible alternatives, i.e. conventional ISDN and B-ISDN.

The competing demands of speed and fault tolerance in finite field Fourier transform implementations have been optimally balanced here by using the chord property in finite field.