| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a radar apparatus which reduces noise figure of a receiver and whose detecting performance can be enhanced, by a method wherein changeover of a beam of a receiving antenna is controlled by amplifying operation and attenuating operation of a low-noise amplifier connected to a connecting terminal of the receiving antenna. SOLUTION: A transmitting antenna 8 radiates a transmitting signal to a target from a transmitting beam 12, and a receiving antenna 8 receives reflected waves from a receiving beam 13a and a receiving beam 13b so as to output a receiving signal. A terminal 16 of the receiving beam 13a and a terminal 17 of the receiving beam 13b are changed over, and both receiving beams can be changed over. A bias of low-noise amplifiers 18 is changed by a low-noise amplifier bias control signal from a signal processing part 11. The low-noise amplifier 18 which is connected to a terminal to be changed over is amplified. The low-noise amplifier 18 which is connected to another terminal is attenuated. The receiving beams 13a, 13b are changed over. The beam of the receiving antenna is electronically scanned. The amplified receiving signal is inputted to the receiving terminal 15 of a transmitter-receiver 7, and it is frequency-converted into a video signal. A distance up to a target and its relative speed are computed by the signal processing part 11 on the basis of it.</p> |
