System characteristics of generalized active-phased-array antennas

The characteristics, such as antenna temperature, G/T and EIRP, of active-phased-array antennas with arbitrary elements have been derived by comparison with the directivity of a lossless passive array antenna. It was recommended that antenna temperature must be obtained from the directivity of the synthesized array antenna and not the array element. The result is quite reasonable compared to a single-feed antenna of the same gain as the array antenna. In the derivation of figures, an equivalent commutation technique was applied successfully, modeling a multichannel array feed on a lossless passive array antenna and an equivalent single channel feed. This procedure will simplify the design and evaluation of active-phased-array antennas.