| 摘要 |
PURPOSE:To hold excellent antenna operation on condition where an input S/J ratio is high by extracting an in-band and an out-band signal of a desired signal band from an antenna input signal and comparing them with each other, and controlling the operation of an adaptive controller on the basis of the obtained output. CONSTITUTION:The in-band component of the desired band of an input signal inputted to an antenna element 12 is detected by a detector 51 and the out-band component is detected by a detector 52; and a comparator 6 compares them with each other. The operation of the adaptive weight controller 4 is controlled on the basis of the output of the comparator 6. Consequently, this device operates as an original PI antenna when the input S/J ratio is low and also holds the S/J ratio of the input signal even when the S/J ratio is high without causing signal loss. Consequently, excellent reception characteristics are maintained in extremely diverse external environments. |
