Concerning power recovered by receiving antenna from incident field

The problem of the power entering a receiver with a random (not necessarily plane) wave incident to the antenna is considered. The problem previously studied by E. L. Burshteyn and B. Ye. Kinber is reconsidered in order: (1) to establish under which conditions the Burshteyn-Kinber formula is correct for power entering a receiver; (2) to obtain a formula which takes into account the effect of mismatch of the feeder line with the antenna and receiver; (3) to give another, simpler version of the formula; and (4) to evaluate the upper boundary of the power entering the rceiver with a given incident field and some additional conditions, and to find the distribution of the antenna field (in a transmission regime), guaranteeing realization of the boundary mentioned. An antenna in the form of a horn with a waveguide transmission line was used in the experiment.