| 摘要 |
PURPOSE:To reduce the measuring error by synthesizing a reception output obtained from other end while grounding alternately both ends of an antenna element having crossed and insulated center part at a prescribed period with an output of a vertical antenna element arranged at the crossing. CONSTITUTION:Two strip antenna elements 4, 5 orthogonal to each other are fitted to the inner face of an insulating board 3 clogging a circular hole 2 provided to a conductive board 1 and a vertical antenna element 10 is provided to the crossing of the elements 4, 5. An output of a terminal 9 provided at both ends of the elements 4, 5 is inputted to a synthesis circuit 18 via switching circuits 15, 16. A terminal 9 of the switching circuits 15, 16 is grounded alternately at a prescribed period and an output of the other end at that time is inputted to the synthesis circuit 18. The synthesis circuit 18 combines the signal and a signal from the element 10 and gives the result to an amplitude detection circuit (not shown in a figure) of a reception circuit (not shown in the figure). Thus, the effect due to noise is reduced and the measurement with high accuracy is attained. |
