Abstractive and selective properties of radio antenna circuits

13. The maximum power which an antenna can abstract from sustained waves and deliver to a detector. To make the delivery of power from sustained waves to the detector associated with a given antenna a maximum, the equivalent resistance of the detector, Rd, should be made equal to the sum of the radiation resistance, Rr, plus the wasteful resistance Rw, of the antenna. Let us assume that the detector is so proportioned, and that the ratio of the resistance is as expressed in equations (1) and (2).