| 摘要 |
PURPOSE:To prevent the deterioration in the reliability from being incurred by providing an antenna current detector to a transmission line transmitting a transmission output to each element of an antenna of multielement array so as to monitor the directivity without giving effect on various characteristics of the antenna element at all. CONSTITUTION:The antenna current detector 1a consists of a directional coupler 101 and a high frequency (RF) bridge circuit 102. The directional coupler 101 detects a progressive wave 101a and a reflected wave 101b on the antenna element 1L. The progressive wave 101a and the reflected wave 101b are synthesized in opposite phase by the RF bridge circuit 102. An antenna current 111a is outputted from an output terminal of the RF bridge circuit 102. Antenna currents 111a-122a, 111b-122b detected by antenna current detectors 1a-12a, 1b-12b are distributed into two by 2-distribution devices 131a-142a, 131b-142b, one output of the 131a-142a, 131b-142b is applied to a synthesizer 201 and similarly the other output is applied to a synthesizer 202. |
