Yoshikazu Asano

Proposal of millimeter-wave holographic radar with antenna switching

This paper proposes a millimeter-wave holographic radar with a simple structure for automotive applications. The simplicity can be realized by switching both transmitting antennas and receiving antennas. Also, a super resolution technique is introduced for the detection of angular positions in the proposed radar. The radar developed experimentally has accomplished an azimuthal angular resolution of less than 2 degrees and an azimuthal field of view (FoV) of more than 20 degrees simultaneously.

Phase-comparison monopulse radar with switched transmit beams for automotive application

We have developed a millimeter-wave automotive radar with /spl plusmn/10-degree azimuthal field of view for an adaptive cruise control. A novel technique has been introduced for realizing the wide field of view. That is a phase-comparison monopulse technique with switched transmit beams. This technique makes it possible to widen the field of view with a simple structure.

NETSTREAM: traffic simulator for evaluating traffic information systems

A traffic simulator NETSTREAM (NETwork Simulator for TRaffic Efficiency And Mobility) has been developed for evaluating traffic information systems such as dynamic route guidance systems. In this paper, a traffic flow model for evaluating traffic information systems in large-scale networks is proposed. The block density method which is one of macroscopic models is improved so that each vehicle is distinguished and lane configurations are taken into consideration. Traffic now can be calculated at high speed in consideration of route choice of each driver using the proposed model. Reduction of average travel time is evaluated in case that the dynamic route guidance system (DRGS) is installed in a whole provincial city using NETSTREAM. In the situation that nearly 66000 vehicles are generated in the network including over 3000 links, the travel times of all the vehicles are calculated in a short time.

Vertical radiation patterns of mobile antenna in UHF band

Theoretical and experimental studies are made on radiation patterns of mobile antennas within the frequency range from 300 to 900 MHz. In order to calculate vertical plane patterns of quarter wavelength monopole and a half-wavelength dipole located on an automobiles roof, a theoretical model of an automobile body is developed, in conjunction with the geometrical theory of diffraction (GTD). The theoretical model consists of three-perfectly conducting plates. It is ascertained from a comparison between calculated and measured results for the feed point impedance and the radiation pattern that the effect of the body and the earth can be well examined with the theoretical model. The results of pattern calculation for the above two antennas show that the radiation patterns depend largely on the configuration of the automobile body and the earth condition. The technique described in this paper can be used as a design tool to estimate radiation performance of mobile antennas.

Proposal of method for estimating received signal characteristics in mobile communication environments

A method for estimating the received signal characteristics (MERS) is developed. The MERS aims at estimating the received power and the fading spectrum at the mobile in mobile communication environments. In MERS, these characteristics are estimated on the basis of both an angular probability density distribution (APD) of wave arrival and a radiation pattern. The APD can also be estimated under arbitrary environmental conditions in the MERS. For the estimation of the APD of wave arrival, a novel propagation model is proposed in this paper. The model consists of an environment model that represents the statistical features of the configuration of buildings along streets and a path model that represents geometrical propagation paths from a transmitting point to a receiving point on the streets. The estimated results of the received signal characteristics are compared with the measured ones. It is proved that the received power and the fading spectrum can be closely estimated.

Estimation method of automotive radar signal for MARPET

We have been developing a millimeter-wave automotive radar performance evaluation tool (MARPET). The MARPET is comprised of two fundamental functions; one is estimating the signal received by the automotive radar, the other is detecting targets by processing the estimated signal. This paper presents a novel estimation method of the radar signal in the MARPET.