focal-plane arrayAn array of dipoles or horn antennas in the focal plane of a radio telescope. Each element in the array is fed to its own receiving system, so that the array can be used to map a region of sky with an efficiency much greater than that of a single element. These arrays may however be difficult to fabricate, especially at submillimeter wavelengths.
focal-plane array[¦fō·kəl ‚plān ə′rā]
A photodetector that has up to a million photosensors on a single semiconductor silicon chip arranged in a rectangular grid matrix that is placed in the focal plane of an optical instrument.