Abstract: A resonant length, helical antenna is provided. According to an embodiment, the antenna includes a plurality of filars having different lengths and that are separately excited in order to provide a wide bandwidth. The bandwidth of the antenna may be further increased by providing switches to selectively terminate an end of the filars in either an open circuit or a short circuit to ground. According to another embodiment, the antenna is provided with a single helical element. The antenna provides efficient operation across a wide bandwidth, particularly at frequencies having good penetration characteristics through the earth. In addition, the antenna provides a radiation pattern having good coverage along an axis of the antenna. The antenna is particularly well suited for use in connection with horizontal directional drilling operations in which it is desirable to avoid contacting underground objects.

Abstract: The present invention relates to an antenna system which is capable of multiband operation from a single antenna aperture. The system provides a high degree of design freedom for achieving desired antenna pattern shapes for all relevant frequency bands. The system achieves this pattern shaping ability by utilizing a unique array configuration which is highly adaptable. The array configuration may include a center array element for each of the relevant frequency bands. In one embodiment of the present invention, a dual frequency band antenna is provided which includes a stacked patch element as the center element in a first frequency band and a crossed dipole element, mounted on top of the stacked patch, as the center element in the second frequency band.