| 摘要 |
<p>PURPOSE:To reduce the calculation quantity for forming a beam for a short- distance vehicle and suppress the power of the unnecessary signal due to the reflection on the ground at a long distance by forming the beam width to about the lateral width of a vehicle regardless of the distance. CONSTITUTION:Radio waves transmitted from an transmitting antenna 1 and a transmitter 2 are reflected on the ground or another vehicle and received by a receiving antenna group 3. The received signal is band-limited, phase- detected, and amplified by a receiver group 4. The output of the receiver group 4 is inputted to a beam forming unit 6. The width of the beam formed by the beam forming unit 6 is nearly matched with the lateral width of another vehicle, and the beam width is made constant regardless of the distance. The output from the beam forming unit 6 is inputted to a target detector 7. The detector 7 judges that another vehicle exists in the range where the power of the preset threshold level or above is detected. The judged result is transmitted to a warning unit 8. The warning unit 8 gives an alarm to an operator 9 when another vehicle is judged to exist in the preset range.</p> |
