Abstract: An apparatus for manually maintaining the level of a radar antenna mounted on a stern pole affixed to the deck or transom of a vessel providing a platform pivotably mounted to a distal end of the pole and oriented to rotate about an axis substantially parallel to the centerline of the vessel. A controller at the lower end of the pole proximal to the cockpit permits manual adjustment of the horizontal angle of the radar antenna to maintain level due to heeling of the boat. The controller utilizes a first plate secured to the pole having a series of detent positions angularly spaced around and equidistant from a center point and a second plate rotatably secured at the center point. A grip handle projecting from the front surface of the second plate permits rotation of the plate when a cooperatively aligned release handle is grasped to withdraw one or more pins extending through holes in the second plate engage the detent positions.

Abstract: A communications structure may include a ground plane, a ground conductor electrically coupled to the ground plane and extending from the ground plane, and a feed conductor. A first antenna branch may be electrically coupled to the ground conductor, with an electrical coupling between the first antenna branch and the ground conductor being spaced apart from an electrical coupling between the ground plane and the ground connector. A second antenna branch may be electrically coupled to the feed conductor, with the first and second antenna branches being spaced apart. In addition, a radio frequency (RF) transmitter and/or receiver may be provided with the ground plane and the feed conductor being electrically coupled to the RF transmitter and/or receiver.

Abstract: A digital broadcasting antenna structure includes a substrate having at least a first and a second face; a main antenna arranged on the first face; an amplifier arranged on the first face and electrically connected to the main antenna; a compensating unit arranged on the second face and electrically connected to the main antenna; a bandwidth modulating unit arranged on the second face and electrically connected to the compensating unit; and a grounding section arranged on the second face and electrically connected to the bandwidth modulating unit. The digital broadcasting antenna structure can receive digital broadcasting signals without being restricted to any specific receiving direction, and is applicable to low, intermediate and high frequency bands to therefore achieve the effects of miniaturization, high bandwidth and low return loss.

Abstract: A slotted bifilar or quadrifilar helix antenna has a plurality of helical antenna elements. The antenna elements have an outer planar surface. A slot element is secured to an interior of the outer planar surface. The slot element extends radially inwardly to a slot element edge. At least two radially opposite slot element edges define a tapered slot. At a shorted point on the antenna, at least one radially opposite pair of slot elements are electrically shorted together. A feed point is axially offset from the shorted point along the antenna axis.