| 摘要 |
PURPOSE:To form a speedometer with an excellent performance while eliminating difficulty in selection of a diode with even characteristics by use of one diode alternately by a short time, namely, employing a time sharing. CONSTITUTION:The moment a switch 13 is connected to a contact S1, a locally oscillated signal is applied directly to a mixer 16 from an oscillator 1 and mixed with a signal received from a receiver 6 to be sent to a switch B14. As the switch B14 is connected to the contact S1 synchronizing a switch A13, a mixed wave is sent to a low pass filter 8. When the switch A13 is connected to a contact S2, the switch B14 is connected to the contact S2 too. At this time, as a locally oscillated signal is applied to the mixer 16 through a high frequency phase shifter 4, the phase is delayed by 90 deg., differently from the preceding case. The mixed wave is sent to a low pass filter 9 via the contact S2 of the switch B14. Such actions are repeated fast alternately and therefore, the locally oscillated signal of the mixed wave to the low pass filter 9 is always delayed by 90 deg. in the phase from that sent to the low pass filter 8. This can shows the moving direction of a moving object 7. |
