Abstract: An antenna capable of being joined to an antenna feed perpendicular to a ground plane includes a conductive radiator and a circular wafer surrounding the radiator. The radiator is tubular and has a longitudinal slot along the entire length thereof, parallel to the radiator's axis. The antenna feed can be connected across the slot. The wafer, made either or a conventional high dielectric isotropic material or of a uniaxial dielectric material, is spaced apart from the radiator and has a thickness approximately equal to the width of the slot, a diameter wherein a ratio of a diameter of the radiator to the diameter of the wafer is approximately 35%, and is located at a height above the ground plane equal to approximately 35% of the length of the radiator. The material of the wafer has a dielectric tensor with high polarizability in the axial direction and can be applied to preexisting antennas. This antenna gives enhanced bandwidth over ordinary slotted antennas.

Abstract: An antenna capable of being joined to an antenna feed perpendicular to a ground plane includes a monopole extending perpendicularly from the ground plane. The antenna feed is joined to the monopole. An innermost shell is provided about the monopole. The innermost shell is made from a dielectric material having a dielectric tensor with high permittivity in the direction of the monopole axis. An intermediate shell provided outside the innermost shell. The intermediate shell also has dielectric tensor having high impedance in the direction parallel to the monopole axis. An outermost shell is provided having a perimeter approximately equal to the length of the monopole. The outermost shell also has a dielectric tensor with high impedance in the direction of the monopole axis.

Abstract: An antenna capable of being joined to an antenna feed and being positioned perpendicular to a ground plane includes a conductive cylinder having a longitudinal slot. The antenna feed is connected across the slot. A plurality of dielectric rods are provided parallel to the slot with rod being positioned much less than one wavelength of the maximum operating frequency away from adjacent rods. The rods each have a length of at least 25 times its mean diameter is made from a material having a dielectric constant greater than 30. The combination of the conductive cylinder and dielectric rods provides increased bandwidth. A kit for modifying existing antennas is further provided.

Abstract: An antenna includes a tubular, conductive radiator having a longitudinal slot formed therein from a first end of the conductive radiator to a second end of the conductive radiator. An antenna feed can be joined to the conductive radiator adjacent to and across the slot. An anisotropic plate is positioned a uniform distance from the conductive radiator, centered above the slot. The plate extends beyond the length of the radiator and is electrically insulated therefrom. An anisotropic tube surrounds the plate and radiator. The anisotropic tube is electrically insulated from the plate and radiator. In use, this antenna gives enhanced bandwidth over ordinary slotted antennas. This can also be applied to preexisting slotted antennas for enhanced bandwidth.