Channel Capacity of Resonant Antennas

Active/nonlinear antennas do not always have a well-defined impedance or bandwidth, which makes it challenging to provide apples-to-apples comparisons between different antenna technologies. Here, we derive a simple expression for the maximum data rate that can be reliably communicated (i.e., capacity) through a narrowband, passive, resonant antenna. The achievable data rate of every active/nonlinear antenna can be compared to our derived limit for passive antennas. Thus, we introduce a new, well-defined metric for characterizing arbitrary antenna technologies.