| 摘要 |
PURPOSE:To avoid the effect to other directions due to the decrease in signal, by using the oscillator having the frequency equivalent to the signal difference between the No. 2 and No. 3 directions, when the No. 1 to No. 2 signal is less than a given value. CONSTITUTION:When the signal f1 toward the No. 1 direction decrease, the discrimination circuit LOG1 selects the switch SW1 to 1-2 and the switch SW2 to 2-3. Thus, the signal in frequency f3' is produced at the output of the mixer MIX3 and it is delivered as the signal toward the No. 3 direction. When the signal f2 is decreased, similarly the switch is selected to 1-1 and 2-2 to produce the signal of f3' at the output of the mixer MIX3. Thus, when the signal toward the No. 1 or No. 2 is decreased, the signal of the shift oscillators SFO3 and SFO4 can deliver the signal from normal direction to the No. 3 (f3) direction. |
