The Demystification and Measurement of Receiving Efficiency

In the 2013 revision of the IEEE Standard for Definitions of Terms for Antennas [1], multiple new terms were added to describe active antenna systems. One such term is receiving efficiency, which was added to describe the behavior of either a passive receiving antenna or an active receiving antenna system. The definition of receiving efficiency contains other new terms such as isotropic noise response and isotropic noise response of a noiseless antenna. These new terms and definitions may cause some confusion for individuals responsible for antenna design and measurement. We attempt to demystify a few of the terms added to IEEE Std 145-2013, especially those terms that relate to receiving efficiency. In addition, we propose a measurement technique for measuring the receiving efficiency of an active receiving antenna system.