Akihiro Kajiwara

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The RCS of a radar target is an important factor related with the radar performance such as the detection, tracking and classification. When dealing with the design of radar system for 26/79GHz short/middle-range radars allocated for next generation perimeter surveillance radars, it is essential to know individual RCS of typical vehicles and pedestrian.(More)
Ultra-wideband impulse-radio (UWB-IR) has lately attracted considerable attention as remote medical sensor, since the effective range is in the order of a few meters and it is not affected by clothes or blankets as well. It is therefore expected to detect the respiratory movement of human body such as patient, which is unique as compared with conventional(More)
Delay profile of an indoor ultra-wideband impulse-radio (UWB-IR) channel should change for the movement of a human body. This paper suggests a human body sensor using the UWB-IR in order to protect a house, not a room, because the radio with high range resolution can penetrate into the walls and the reflected paths from human body and the like should be(More)
Ultra-wideband impulse-radio (UWB-IR) channel with omni-directional antenna was experimentally investigated inside a vehicle body with passengers where the interference power out-radiated from the vehicle is also discussed. From the result, the RMS delay spread and average delay, which are considerably degraded as compared with the use of directional(More)
This paper presents an ultra wideband (UWB) microwave sensor using a stepped-FM scheme. Impulse-radio UWB sensor requires high speed A/D in order to synchronize and detect the nanosecond pulse echo. Also it may be difficult to use the bandwidth wider than 500MHz without causing interference with other wireless systems. Our suggested scheme which does not(More)
Requirement for monitoring the state of the elderly in care facilities is increasing year by year and the increase in accidents involving them becomes great concern. In this paper, an ultra-wideband impulse-radio (UWB-IR) monitoring sensor is suggested which focuses on the bed status most critical to the elderly that need the assistance immediately.(More)
In-vehicle ultra-wideband impulse-radio propagation characteristics are investigated experimentally for two types of vehicle, sedan and one-box, and the effects of in-vehicle antenna locations and passengers on propagation characteristics are discussed where four frequency spans of 1, 3, 5 and 7 GHz are considered. From the measurement results, these delay(More)