Multiple frequency band antenna

摘要

An active array antenna system comprises a plurality of element antennas (101) and radio frequency circuits connected to the element antennas. The radio frequency circuits comprises first frequency converters (104) provided to correspond to the element antenna and converts the frequency between a carrier-wave frequency and a first intermediate-frequency by using a carrier-wave frequency band local signal, second frequency converters (110) provided to correspond to the element antenna and converts the frequency between the first intermediate-frequency signal and a second intermediate-frequency which is lower than the first intermediate frequency by using an intermediate-frequency band local signal, and a variable phase shifter circuit (113) for individually controlling the phases of the intermediate-frequency local signals which are supplied to the second frequency converters (110). A variable phase shifter circuit for beam scan can be constituted at a low cost so that an active array antenna system which can be realized at a low cost is provided. <IMAGE>