Antenna G/T degradation with inefficient receive antennas at HF (2–30 MHz)

This paper presents the antenna G/T degradation incurred when communications systems use very inefficient receive antennas. This work is relevant when considering propagation predictions at HF (2–30 MHz), where it is commonly assumed that antennas are efficient/lossless and external noise dominates over internally generated noise at the receiver. Knowledge of the antenna G/T degradation enables correction of potentially optimistic HF predictions. Simple rules-of-thumb are provided to identify scenarios when receive signal-to-noise ratios might be degraded.