| 摘要 |
PURPOSE:To measure a coming direction accurately by detecting the phase of the fundamental wave from the phase of a double times frequency component of the fundamental frequency after composing an output of an antenna having a point symmetrical directional characteristic and of a nondirectional antenna and adding it to a square-law detecting circuit. CONSTITUTION:Two loop antennas L1 and L2 are arranged at right angles each other and a nondirectional antenna K is provided in its vicinity. The outputs of antennas L1 and L2 and fundamental waves having different phase by 90 deg. each other from generator O are added to balanced modulators Mc and Ms respectively. After composing these outputs and output of an antenna K in a composite circuit S, the composite output is subjected to a square-law detection in a square-law detector D through an amplifier A. The two times component of the fundamental wave is extracted with filter F2 and the phase with respect to the fundamental wave is measured after adding the extract to a phase measuring device Q through a 90 deg. phase devide P2. The fundamental wave is indicated by an indicator H selecting a value of the measuring device Q with a selector G when its output is positive through the filter F1 and the phase device P1. |
