Signal/noise-ratio performance of loaded wire antennas

Expressions for the signal/noise ratio of an antenna and of a receiving system are derived. Both signal/noise ratios are degraded by reductions in antenna efficiency and directivity. Raising an inductor from the foot of a resonant short monopole will improve the signal/noise ratio. Resistance-loaded and other travelling-wave monopoles are less directional than corresponding standing-wave structures and degrade the antenna signal/noise ratio, but the broad-band system signal/noise ratio can be improved owing to better impedance matching