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A new isolated AC-DC converter for an on-board charger has been developed. It consists of an AC-DC converter with Gradationally Controlled Voltage Inverter and an isolated zero-voltage-switching DC-DC converter. To make these converters cooperate efficiently over the wide range of operating voltage conditions, we developed an optimized converter control. As a result, the new isolated AC-DC converter can operate with power conversion efficiency of over 94%.

A way to design the STC performance for automotive millimeter-wave radar is proposed. With a statistical analysis on the data achieved in an experiment at a practical driving situation, the probability distribution of the received signal according to the distance is obtained. The experiment was carried out using FM-pulse Doppler radar we developed. Based on the obtained characteristics, a necessary compression of radar dynamic range is specified. With designed STC in the proposed way, the cost of the radar has been reduced while achieving a wide detection area up to 150m.

The vehicular collision avoidance millimeter-wave radar that uses an FM-pulse Doppler method is proposed. This radar is constituted with the FM-CW radar method and the pulse Doppler radar method. This radar method has combined the advantages that the precision of the measurements of distance and speed of the target that the FM-CW radar method provides, and the low target mis-recognition probability that the pulse Doppler radar method provides. The millimeter-wave radar using this method was produced using comparatively simple circuits The experimental data that was obtained with this radar and with the FM-CW radar are compared with each other. The effectiveness of the FM-pulse Doppler method was investigated using data obtained from on the road environment using a target vehicle and some objects.

A Frequency Modulated Continuous Wave (FMCW) radar using only in-phase channel is advantageous for automotive applications. In this radar, we have to search the pairs of beat frequencies in an up-chirp mode and a down-chirp mode for multiple targets similarly to conventional FMCW radar. However the number of combinations to search pairs is larger than that for the conventional FMCW radar. Therefore, false targets by mistaking the combination of these pairs increase. In this paper, we propose a novel signal processing algorithm to reduce the false targets. We extract only the beat frequencies of the relative moving targets using the differential of the frequency power spectra of the up-chirp mode and the down-chirp mode. We can reduce choosing incorrect pairs by separating stationary targets and moving targets. We have conducted some simulations to confirm the capability of the proposed algorithm.

This paper describes a compact radar for automotive applications. A Frequency Modulated Continuous Wave (FMCW) radar is employed here with only in-phase channel. Since this radar cannot detect a sign of beat frequency of receiving signals, we have the ambiguity about the range and the velocity of targets. In this paper, we propose a novel FMCW automotive radar to suppress this ambiguity.