Rectangular Waveguide Flange Aperture-Shared Antenna with Extended Array Angle-of-Arrival

In the decommissioning work of the Fukushima Nuclear Power Plant, an aperture-shared antenna with an extended array angle-of-arrival estimation to estimate the location of sensors inside a primary containment vessel is proposed. The proposed antenna comprises a downlink antenna consisting of an open-ended rectangular waveguide and an uplink microstrip array antenna with eight elements configured on a waveguide flange. By performing array expansion processing on the array antenna on the flange, it is possible to suppress the grating lobes caused by the sparse array arrangement and wide-angle direction-of-arrival estimation can be realized.