Patent ID: 7391386
Filing Date: 2008-06-24
Classification: H01Q,H04B

Abstract:
1. A controller for controlling an array antenna, said array antenna comprising: a radiating element for receiving a transmitted radio signal; a plurality of parasitic elements each provided to be distant from said radiating element at a predetermined interval; and a plurality of variable reactance elements connected to said parasitic elements, respectively, wherein said controller changes reactances to be set to said variable reactance elements, respectively, so that said parasitic elements operate as waveguides or reflectors, thereby changing a directivity characteristic of the array antenna, wherein said controller comprising: a control device for selecting one reactance set from among a plurality of reactance sets in a plurality of cases of setting the plurality of reactance sets, respectively so as to be able to obtain a diversity gain equal to or larger than a predetermined value, and so as to keep an input impedance of said array antenna substantially unchanged, based on the radio signal received by said array antenna, based on a signal quality of the radio signal received in each of the plurality of cases according to a predetermined selection criterion, and for setting the selected reactance set to the plurality of variable reactance elements, respectively.