摘要:
A dual mode antenna can be joined to an antenna feed. The antenna includes a slotted cylinder radiator that can be connected to the first conductor of the antenna feed and an electrically conductive ground plane that can be connected to the second conductor. The radiator axially extends perpendicularly from the ground plane and is electrically insulated therefrom. The first conductor can be joined to the radiator near one side of the slot. A reactive load is joined between the ground plane and the radiator near an opposite side of the slot. The reactive load impedes lower frequencies from the ground plane to the radiator. This allows the radiator to function as a monopole at lower frequencies and a slotted cylinder at higher frequencies.
摘要:
An antenna for connection to a feed includes a substrate with a conductive ground plane. An emitter is positioned on the top face of the substrate, and the feed is connected to the emitter and ground plane. A spacer is positioned on the substrate above the emitter and one layer of high dielectric constant rods is positioned above the spacer. The rods are positioned in a single plane, coplanar with the emitter, and parallel to the dominant current distribution when the emitter is active. Further layers of spacers and rods can be positioned at a predetermined angle to the rods beneath. A kit is further provided for application of spacers and rods to preexisting antennas.
摘要:
An antenna can be joined to an antenna feed and positioned perpendicular to a ground plane. The antenna includes a conductive radiator having a cylindrical portion. A slot is formed in the entire length of the cylindrical portion. Two parallel fins extend from the cylindrical portion at the slot. The fins can extend inwardly or outwardly. The antenna feed is connected to the conductive radiator on either side of the slot. An anisotropic magnetic material having a uniaxial permeability tensor is positioned in the slot between the two fins. This material is oriented such that it has a much greater permeability in the radial direction than in the other directions. The interior of the cylindrical portion can be filled with a dielectric material.
摘要:
A buoyant cable antenna system includes an HF antenna section connected to an outboard end of a VLF/LF antenna. With respect to the HF antenna, the VLF/LF appears to be a standard coaxial cable so that the HF antenna can be configured as desired for HF antenna operation. The VLF/LF antenna is comprised of a segment of coaxial cable. The inboard end of the braided outer conductor of the segment of coaxial cable is connected to ground through a capacitor so that the VLF/LF signals are effectively isolated from ground. In this way, VLF/LF currents are induced on the outer braided conductor of the segment of coaxial cable to thereby operate as the VLF/LF antenna.
摘要:
A microstrip patch antenna with progressive slot loading is provided. A rectangular patch of electrically conductive material has a plurality of slots formed therein with each slot having its center aligned with the centerline of the patch's long dimension. Each slot further has its longitudinal axis perpendicular to the centerline. The slots are arranged in an order starting at a position n=1 that is furthest from the patch's feedpoint so that, for an n-th slot, the inequalities Ln>Ln+1 and Wn
摘要:
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.
摘要:
An antenna for connection to a feed includes a substrate with a conductive ground plane. An emitter is positioned on the top face of the substrate, and the feed is connected to the emitter and ground plane. A spacer is positioned on the substrate above the emitter and one layer of high dielectric constant rods is positioned above the spacer. The rods are positioned in a single plane, coplanar with the emitter, and parallel to the dominant current distribution when the emitter is active. Further layers of spacers and rods can be positioned at a predetermined angle to the rods beneath. A kit is further provided for application of spacers and rods to preexisting antennas.
摘要:
An antenna includes a first antenna section that can be joined to an antenna feed. The first section has conductive elements in series with reactive loads. The reactive loads are positioned with a regular spacing. The reactive loads and spacing are optimized for operation of the first section at the highest frequency. Additional antenna sections having successively lower frequencies are joined in series to the first antenna section. Each additional section has conductive elements joined in series with reactive loads at a particular spacing. The additional sections spacing and reactive loads are provided to work in conjunction with the higher frequency antenna sections to optimize the antenna for an additional frequency. A method for making such an antenna is further provided.
摘要:
A method for improving bandwidth and gain of a microstrip patch antenna and a microstrip patch antenna are provided. The method includes forming a highly anisotropic superstrate, and positioning the highly anisotropic superstrate at a predetermined distance away from the ground plane side of the microstrip patch antenna, increasing the bandwidth of the microstrip patch antenna. The antenna provides a microstrip patch antenna having a highly anisotropic superstrate. The highly anisotropic superstrate can include a spacing layer, a dielectric material positioned on the spacing layer and a plurality of conductive strips disposed on the dielectric layer.
摘要:
An antenna element with a single-conductor antenna is provided within a removable core. The removable core is mounted within a hollow liner by sliding the core into the hollow liner. A pull cable may be attached to an end of the removable core to pull the core through the outboard end of the hollow liner. Due to reduced strain on the core as compared to the liner, the single-conductor antenna may be formed in segments interconnected with capacitors for adjusting the antenna gain to a maximum in the vicinity of a desired operating frequency or frequencies.