| 摘要 |
<p>PURPOSE:To use an antenna small-sized lightweight and inexpensive like a plane antenna in this apparatus by preventing the effect due to the direct wave emitted from a transmission antenna and directly received by a receiving antenna. CONSTITUTION:The output signal 21a from an oscillator 1 is distributed into two signals by a distributor 2. One distributed output signal 21b is emitted to space from a transmission antenna 3. The other output signal 21c distributed by the distributor 2 is inputted to a synthesizer 6 as a signal 21h of a state equal to a receiving signal 21f due to a direct wave in amplitude but different therefrom in phase by 180 deg.. Therefore, when the signal 21h and the receiving signal 21f are synthesized by the synthesizer 6, a direct wave component 21df is cancelled and only a reflected wave component 21ef is outputted from the synthesizer 6.</p> |
