Abstract: An electrically directable antenna system is provided which is tunable to individual stations in the FM band. The antenna system includes a pair of crossed, forshortened dipole components which are arranged to be mutually perpendicular. Each of the dipole components includes a pair of longitudinally aligned arms which are flared at their outer ends so as to be shaped generally like an arrow. At their inner ends, these arms are connected to a narrow bandwidth tuner network which is designed to resonate the dipole components at a frequency corresponding to a selected station and to impedance match each of the dipole components to the input of the FM receiver. The tuner network includes a bandwidth control, which is operable to produce a predetermined impedance mismatch between the dipole components and the receiver input so that, without changing the frequency to which the antenna system is tuned, the overall antenna system gain can be made substantially constant over the entire FM band.

Abstract: A center-fed VHF dipole antenna structure particularly adapted for 30-80MHz peration wherein one half of the radiating structure comprises the outer conductor of a coaxial feedline which includes a low-loss cable choke at the lower end of the half dipole length of the feedline while the other half of the dipole consists of a conventional radiating conductor element. Additionally, remotely controlled variable impedance elements are included at the feedpoint to provide selective coarse and fine tuning of antenna resonance.

Abstract: A thick folded doublet antenna, the diameter of the current-receiving wire of which is on the order of ten times greater than that of the folded wire, the current-receiving wire comprising two half-wires of exterior symmetrical cylindrical form terminating at the center in two opposed frusto-conical portions, the small bases of which are close to each other, a coaxial conductor having an impedance of approximately 50 ohms extending axially through one of the half-wires, characterized in that the central conductor of the coaxial line is extended across the space between the bases of the frusto-conical portions and penetrates coaxially into a bore in the other half-wire, the central conductor being insulated from the other half-wire, the length of penetration of the central conductor being very short, and the coaxial line being supplied with signals at frequencies whose wavelengths are approximately six times the total height of said doublet antenna.

Abstract: A thick folded dipole having an operating frequency which is far less than he first resonance frequency. The dipole includes a folded strand and a thick fed strand having a diameter which is about ten times greater than the diameter of the folded strand. The fed strand comprises two spaced apart cylindrical half strands having ends in the form of conical frustums and coaxial bore holes. A center conductor of a coaxial cable extends through the folded strand, the bore hole of one half strand, the space between the half strands and into the bore hole of the other half strand. Symmetrical spaced apart short circuits for matching the radiation impedance of the dipole by varying the distance between the short circuits are provided between the fed strand and the folded strand. In another embodiment there is disclosed a thick folded half dipole including a folded half strand and a thick fed cylindrical half strand.

Abstract: A whole wave antenna is placed on an insulating support and has its feed input located a little above its middle. In order to reduce secondary lobes inductive reactances are serially inserted in the antenna on each side of its feed input so as to produce a rapid rotation with inversion of the phase of the currents on each side of the feed input.

Abstract: A vertical grounded antenna is supplied at one third of its height. The antenna is substantially a whole wave antenna and, in order to reduce the secondary lobes of the vertical pattern of said antenna, its height is so determined as to produce an inversion of the sign of the phase of the current on each side of the feed input.