Microwave radar level measuring apparatus

Abstract

Abstract PURPOSE:To measure a level to be measured accurately, by a method wherein a correction signal is generated in the phase the same as a noise signal to be mixed into a received signal to remove undesired signals with subtraction of the correction signal from the received signal. CONSTITUTION:A part of a transmission microwave is picked up with a directive connector 20 to be supplied to a magic T circuit 23 in a correction circuit 24. A mobile short-circuit plate 26 is connected to the circuit 23 through a waveguide tube 25, the length of which 25 is made equal to the length of the antenna at a measuring device plus distance between the antenna 1 and the magic T circuit 3. An output of the circuit 23 is applied to an FM detector 27 to obtain a beat signal with the cycle the same as that of an undesired signal. Signals generated from detectors 4 and 27 are inputted into amplifiers 5 and 28 to be adjusted so that the amplitude of a correction signal is the same as that of the signals. Outputs of the amplifiers 5 and 28 are inputted into a subtractor 29 to remove undesired signal from received signal thereby achieving a ratio between a beat signal due to the reflected wave from an object to be measured and the undesired signal.

Inventors

• 👤 Takuya Kusaka
• 👤 卓也 日下
• 👤 Yutaka Kawada
• 👤 豊 川田
• 👤 Kenichi Inoue
• 👤 憲一 井上
• 👤 Kiyotaka Ishibashi
• 👤 清隆 石橋

Bibliographic Details