Antenna device
AssigneeNational Space Development Agency of Japan
InventorToshihiro Sezai
Life of this patent
Estimating the term…
Abstract
An antenna system is made up by a main antenna and a sub antenna which is adjacent the main antenna in a direction not perpendicular to the direction of beam scan of the main antenna and which has a beam axis coincident with a beam axis of the main antenna. Antenna beams of the antenna system are scanned by a scan device. Received signals of both the antennas are subjected to a multiplication process under phase coherent condition in a phase-coherent multiplying device. A signal corresponding to a maximum frequency component in the output signal of the phase-coherent multiplying device is output by a frequency discriminating device and then subjected to a signal conversion process in a signal converting device. Information about a radio wave source only in the direction of the antenna beams is thus obtained.
Claims6
An antenna device comprising:
- an antenna system made up by a main antenna for receiving a radio wave and at least one sub antenna which is adjacent said main antenna in a direction not perpendicular to a direction of beam scan of said main antenna and which has a beam axis coincident with a beam axis of said main antenna;
- means for scanning antenna beams of said antenna system;
- means for executing a phase-coherent multiplication process of received signals of said main antenna and said sub antenna to output a phase term produced depending on a length of a component of a center-to-center spacing between said main antenna and said sub antenna in the direction of beam scan, a wavelength of a received radio wave and an angle of a radio wave source with respect to a direction of the antenna beams;
- and
- means for outputting a signal corresponding to a maximum frequency component corresponding to time-dependent fluctuations of said phase term output from said means for executing a phase-coherent multiplication process,
- whereby amplitude and phase information about the radio wave source only in the direction of the antenna beams is obtained.
Dependencies are inferred from the claim text.