Antennae in which the corresponding radiative element contains at least one multilevel structure formed by a set of similar geometric elements (polygons or polyhedrons) electromagnetically coupled and grouped such that in the structure of the antenna can be identified each of the basic component elements. The design as such that it provides two important advantages: the antenna may operate simultaneously in several frequencies, and/or its size can be substantially reduced. Thus, a multiband radi...

Antennas designed for use in producing effective electromagnetic capture zones for transponders mounted on moving vehicles. The antenna systems disclosed are principally designed to be mounted at or near the surface of a roadway carrying the vehicle whose transponder is to be interrogated. A principal advantage of the antennas of the invention is minimal interference with normal operation of the road and greatly reduced cost of installation when used in providing vehicle identification, toll col...

This invention relates to radio antennae, and in particular to dielectric-clad antennae of the kind comprising a length of conductor the electrical length of which is effectively increased by a cladding of dielectric material. The disclosure describes how the physical height of an antenna, typically an HF or VHF wire monopole antenna can be reduced in relation to its electrical length by means of a thin cladding of dielectric material having a relative magnetic permeability substantially greater...

A travelling wave stripline antenna array adapted for use as a frequency-swept antenna, comprising a pattern of conducting material on an insulating substrate with a conducting backing, the pattern comprising a feeder strip and a plurality or radiating antenna elements each in the form of a strip attached to and extending tranversely away from the feeder strip, and having an open circuit termination at its free end. At least some, and preferably all, of the strips are formed with a longitudinal ...

Compact radio antennae are disclosed which comprise an extended conductor, such as a wire, arranged to form an elongated structure. The conductor is arranged in a plurality of windings comprising windings of opposite senses positioned coaxially in proximate relation. In one form the conductor is arranged in a series of helical windings all coaxial, to form a cylindrical structure, and successive windings in the series are alternately left-handed and right-handed. In another form the conductor is...

Antennae in which the corresponding radiative element contains at least one multilevel structure formed by a set of similar geometric elements (polygons or polyhedrons) electromagnetically coupled and grouped such that in the structure of the antenna can be identified each of the basic component elements. The design is such that it provides two important advantages: the antenna may operate simultaneously in several frequencies, and/or its size can be substantially reduced. Thus, a multiband radi...

Antennae in which the corresponding radiative element contains at least one multilevel structure formed by a set of similar geometric elements (polygons or polyhedrons) electromagnetically coupled and grouped such that in the structure of the antenna can be identified each of the basic component elements. The design is such that it provides two important advantages: the antenna may operate simultaneously in several frequencies, and/or its size can be substantially reduced. Thus, a multiband radi...

Antennae in which the corresponding radiative element contains at least one multilevel structure formed by a set of similar geometric elements (polygons or polyhedrons) electromagnetically coupled and grouped such that in the structure of the antenna can be identified each of the basic component elements. The design is such that it provides two important advantages: the antenna may operate simultaneously in several frequencies, and/or its size can be substantially reduced. Thus, a multiband radi...

A pennant construction (10) for a vehicle antennae (100) comprising a pennant member (20) fabricated from a very thin, lightweight, and strong material (21) formed into a generally triangular configuration and having an adhesive strip (24) formed on one side and adjacent one edge of the pennant member (20) for adhesively securing the pennant member (20) both to the antennae (100) and itself.

Dipole whip antenna arrangements are disclosed which are capable of operating over a wide frequency band without the use of continual manual or automatic tuning. This is achieved by connecting the dipole whip antenna to the ground plane through a reactance network which is specially designed so as to match the impedance at the feed point of the dipole arrangement to a desired value over the desired frequency band. For this purpose, the reactance network is an active network, and operates by effe...