On the Power Absorbed and Scattered by an Antenna

We discuss the powers absorbed and scattered by a receiving antenna. Most antennas scatter more than they absorb. Antennas that scatter less power than they absorb are rare, and the few examples that have been presented are all based on numerical optimization. This note presents a simple conceptual model - a partially transparent aperture antenna - which provides physical insight into the case where the scattering is less than the absorption. Finally, we comment on the far field in the forward-scattering direction, noting that the total field actually is increased, although the scatterer blocks the incident field.