Efficient Small Antennas

An efficient and electrically small antenna element is proposed. The proposed space-filling curve (SFC) top-loaded antenna provides a relatively large bandwidth, comparable to a standard ¼ wavelength monopole within just a fraction of the total height. This class of electrically small antenna systems can be reconfigured to operate within different modes including separate and distinct frequency bands, single and stable broad bands as well as with different polarizations, depending upon the configuration. The relatively high gain is maintained in a stable pattern throughout the bandwidth and unlike many top-loaded monopoles, the SFC antenna requires no external matching network. With high efficiency and very compact size, these antennas are ideal for applications where a low-visible antenna signature is required without the sacrifice of antenna performance. The SFC antenna designs have several scalable factors which allow for specific antenna designs to be custom tailored as needed. When utilized with PIN diode switches, it may be possible to reconfigure the antenna element “on-the-fly” through the use of DC-biasing.