Abstract: Antenna embodiments are illustrated that are particularly suited for use in aircraft navigation, identification and collision avoidance systems. An exemplary antenna embodiment operates about a center wavelength and in association with a ground plane and comprises first and second grounded, shortened, and top loaded monopoles. These monopoles are spaced apart above a ground plane and each of them includes a feed post, a shorted post, and a top load wherein the shorted post is spaced from the feed post, is coupled to the ground plane, and has a length less than one fourth of the center wavelength. In addition, the top load is coupled to the feed post and the shorted post and is configured along orthogonal minor and major axes of the top load to have a width along the minor axis and a length along the major axis that exceeds the width.

Abstract: Antenna embodiments are illustrated that are particularly suited for use in aircraft navigation, identification and collision avoidance systems. An exemplary antenna embodiment operates about a center wavelength and in association with a ground plane and comprises first and second grounded, shortened, and top loaded monopoles. These monopoles are spaced apart above a ground plane and each of them includes a feed post, a shorted post, and a top load wherein the shorted post is spaced from the feed post, is coupled to the ground plane, and has a length less than one fourth of the center wavelength. In addition, the top load is coupled to the feed post and the shorted post and is configured along orthogonal minor and major axes of the top load to have a width along the minor axis and a length along the major axis that exceeds the width.

Abstract: Antenna system embodiments are shown which are especially suited for mounting on aircraft and for operation across widely-spaced frequency bands. Embodiments include blade members positioned in a ring arrangement and tuning circuits that are each coupled between a respective pair of the blade members and configured to successively remove blade members from operation as the operational frequency increases.

Abstract: Antenna system embodiments are shown which are especially suited for mounting on aircraft and for operation across widely-spaced frequency bands. Embodiments include blade members positioned in a ring arrangement and tuning circuits that are each coupled between a respective pair of the blade members and configured to successively remove blade members from operation as the operational frequency increases.