Abstract: An antenna system is provided including a rapidly expandable-collapsible housing which mounts two sections of fabric material each having an array of antenna elements formed of electrically conductive material such as copper thread embedded in the fabric sections. The fabric sections are movable between the expanded and collapsed positions with the housing and are located in different planes.

Abstract: An antenna including an electrically conductive portion defined substantially by a self-similar geometry present at multiple resolutions. The electrically conductive portion includes two or more angular bends and is configured to radiate broadband electromagnetic energy. The antenna further includes an electrically non-conductive portion that structurally supports the electrically conductive portion.

Abstract: There is provided a broadband antenna including: an insulating block having opposing first and second main surfaces and a side surface between the first and second main surfaces; a first radiator pattern formed on the first main surface and having a tapered slot with an open end; and a second radiator pattern including two patterns connected to opposing ends of the first radiator pattern, respectively, and extending to the second main surface.

Abstract: A novel loaded antenna is defined in the present invention. The radiating element of the loaded antenna consists of two different parts: a conducting surface and a loading structure. By means of this configuration, the antenna provides a small and multiband performance, and hence it features a similar behaviour through different frequency bands.

Abstract: A log-periodic antenna having a layer of dielectric media interposed between a microstrip log-periodic portion and a slot log-periodic portion is described. Also described are antenna embodiments having a curvilinear, electrically conductive feed line and a substantially co-extensive curvilinear slot transmission line and additional embodiments including an array of two or more log-periodic antennas.

Abstract: A log-periodic dipole array antenna including a dielectric substrate, and antenna elements, symmetrical microstrip lines and baluns disposed on two corresponding surfaces of the substrate is provided. The antenna elements on each surface are connected to one side of the corresponding symmetrical microstrip line, respectively. The width of at least one antenna element on each surface is broadened gradually outwards from the side of the antenna element, which is connected to the corresponding symmetrical microstrip line. In addition, the baluns are connected to the ends of the corresponding symmetrical microstrip lines, respectively. The antenna elements on one surface are in a mirror-image relation to those on the other surfaces. The log-periodic dipole array antenna features increased broadband with a thin and compact-size, better margin in design to meet different bandwidth requirements.

Abstract: An antenna includes at least one element whose physical shape is at least partially defined as a second or higher iteration deterministic fractal. The resultant fractal antenna does not rely upon an opening angle for performance, and may be fabricated as a dipole, a vertical, or a quad, among other configurations. The number of resonant frequencies for the fractal antenna increases with iteration number N and more such frequencies are present than in a prior art Euclidean antenna. Further, the resonant frequencies can include non-harmonically related frequencies. At the high frequencies associated with wireless and cellular telephone communications, a second or third iteration, preferably Minkowski fractal antenna is implemented on a printed circuit board that is small enough to fit within the telephone housing.

Abstract: Disclosed is a broadband log-periodic dipole antenna, which has first and second radiating elements alternately and symmetrically arranged in both surfaces of a dielectric substrate according to the corresponding PCS frequency band, IMT-2000 frequency band, and wireless LAN (IEEE 802, 11a/b) frequency band, so that the first and second radiating elements are alternately supplied with signals to make the impedance matching, thereby producing high gain in each of the resonant frequency bands and preventing the distortion of the radiating patterns owing to the broadband characteristics. The arrangement of the first and second radiating elements in both surfaces of the dielectric substrate considerably also reduces the size of the antenna, thereby facilitating mass production with low cost.

Abstract: There is disclosed an antenna having a tapered radiating element possessing a slow-wave structure along a tapered radiating edge thereof. The radiating element is combined with a ground plane conductor to form a monopole antenna. The slow-wave structure supports an increased antenna operating bandwidth and reduced aperture clutter by being shaped to increase the radiative rate of loss of energy from signals propagating along the slow-wave structure. A log-periodic distribution in the shaping of serrations within the slow-wave structure provides substantially frequency-independent performance across the bandwidth.

Abstract: A directional antenna array is provided that includes a driven element and a first parasitic element separated from the driven element with the first parasitic element and/or the driven element having a width that is greater than about one-half a percent (0.5%) of an free-space wavelength of the directional antenna array. Alternatively or in conjunction, the directional antenna array includes a balun structure that is configured to couple the driven element to at least one of an electromagnetic energy source and an electromagnetic sink, and the balun structure includes a dipole structure, a first feed point extending from the dipole structure and a second feed point extending from the first parasitic element.

Abstract: A first fractal antenna of iteration N?2 in free space exhibits characteristics including at least one resonant frequency and bandwidth. Spacing-apart the first fractal conductive element from a conductive element by a distance ?, non-planarly or otherwise, preferably ?0.05? for non-planar separation for frequencies of interest decreases resonant frequency and/or introduces new resonant frequencies, widens the bandwidth, or both, for the resultant antenna system. The conductive element may itself be a fractal antenna, which if rotated relative to the first fractal antenna will alter or tune at least one characteristic of the antenna system. Forming a cut anywhere in the first fractal antenna causes new and different resonant nodes to appear. The antenna system may be tuned by cutting-off a portion of the first fractal antenna, typically increasing resonant frequency. A region of ground plane may be formed adjacent the antenna system, to form a sandwich-like system that is readily tuned.

Abstract: An optical antenna collects, modifies and emits energy at light wavelengths. Linear conductors sized to correspond to the light wavelengths are used. Nonlinear junctions of small dimension are used to rectify an alternating waveform induced upon the conductors by the lightwave electromagnetic energy. The optical antenna and junctions are effective to produce harmonic energy at light wavelengths. The linear conductors may be comprised of carbon nanotubes that are attached to a substrate material, which may then be connected to an electrical port.

Abstract: The present invention relates to connecting and impedance matching a balanced electrical signal, such as that received by an antenna, with an unbalanced transmission circuit, such as that delivered to an amplifier. A planar circuit board is described that delivers signals having opposite polarization collected by different antenna arms to a location for convenient connection to a twin-lead transmission line. Circuit topologies for the circuit board are described that provide relatively low loss and low cross-coupling. A tapered microstrip balun is also described that includes two conducting microstrips on opposing faces of a dielectric separator. Stepped or tapered microstrips at the balanced input port of the balun provide an impedance transforming section electrically connecting to a mode transducing section, in which one of the microstrips tapers outward to form a substantially wider strip. Appropriate choice of parameters is shown to lead to favorable performance in a compact balun.

Abstract: An antenna array comprised of a fractile array having a plurality of antenna elements uniformly distributed along a Peano-Gosper curve. An antenna array comprised of an array having an irregular boundary contour comprising a plane tiled by a plurality of fractiles covering the plane without any gaps or overlaps. A method for generating an antenna array having improved broadband performance wherein a plane is tiled with a plurality of non-uniform shaped unit cells or an antenna array, the non-uniform shaped and tiling of the unit cells are then optimized. A method for rapidly forming a radiation pattern of a fractile array employing a pattern multiplication for fractile arrays wherein a product formulation is derived for the radiation pattern of a fractile array for a desired stage of growth. The pattern multiplication is recursively applied to construct higher order fractile array forming an antenna array.

Abstract: A conductive member may include a conductor having a pair of opposed parallel surfaces and a cable guide arranged inside the conductor. In another embodiment, a conductive member may include a conductive bar having a pair of opposed parallel surfaces and a convex surface connecting respective first ends of the pair of opposed parallel surfaces to one another. An embodiment of a method for forming a conductive member includes forming a cable guide arranged inside a conductor having opposed parallel surfaces, where the cable guide is oriented in a direction substantially parallel to the opposed parallel surfaces. In an embodiment of an antenna, the antenna includes a conductor having a pair of opposed lateral surfaces, and a cable guide arranged inside the conductor and oriented in a direction substantially parallel to that of the opposed parallel surfaces.

Abstract: Disclosed is a noise shield type multi-layered substrate which is advantageous in terms of shielding leaked magnetic flux and cross-talk by disposing a magnetic material onto at least one of circuit patterns, passive components and active components, thus blocking noise generated from the circuit patterns, passive components and active components. Thus, malfunctions of neighboring circuit patterns and various parts due to leaked magnetic flux are prevented. A method of manufacturing the noise shield type multi-layered substrate is also provided.

Abstract: A pseudo-fractal antenna is provided comprising a dielectric, and a radiator proximate to the dielectric having an effective electrical length formed in a pseudo-fractal geometry. That is, the radiator includes at least one section formed in a fractal geometry and at least one section formed in a non-fractal geometry. The antenna can be either a monopole or a dipole antenna. For use in a wireless communication telephone, the antenna operating frequency can be approximately 1575 megahertz (MHz), to receive global positioning satellite (GPS) information. In one aspect, the radiator has a fractal geometry section formed as a Koch curve. When the antenna is a dipole, the counterpoise can also be a pseudo-fractal geometry with a section formed in Koch curve fractal geometry section. The radiator can be a conductor embedded in the dielectric. Alternately, the radiator is a conductive line overlying a dielectric layer.

Abstract: A self-similar log-periodic antenna is described comprising a plurality of substantially triangular conductive elements, 4, symmetrically disposed in either planar or curved configurations about a central conductive boom to form an antenna arm. Two or more antenna arms are assembled into an antenna by symmetrically locating such antenna arms substantially in the shape of a pyramid (for planar arms) or in a conical shape (for curved arms). Some embodiments include a conductive fin, 5, to reduce cross-polarization coupling between antenna arms. Some embodiments include a grounded conductive shield on the interior of the antenna providing electromagnetic shielding for the interior region of the antenna while preserving the self-similar geometry of the antenna and shield combination.

Abstract: A log-periodic dipole antenna (10) includes a boom (12) which through insulator blocks (15) carries a plurality of elements (13) consisting of element halves (13A, 13B) which extend in opposite directions from the boom (12). Spaced transmission wires (38A, 38B) extend along the boom (12) without crossing each other and yet communicate with alternatingly opposite element halves (13A, 13B) of adjacent elements (13) in view of their connection with brackets (30A, 30B) attached to element halves (13A, 13B). The transmission wires (38A, 38B) are spaced at the point of communication with each element (13) a distance proportional to the impedance of that particular element (13) by virtue of their being attached at different locations along the brackets (30A, 30B).

Abstract: A dual polarized variable beam tilt antenna (10) having a plurality of offset element trays (12) each supporting pairs of dipole elements (14) to orient the dipole element pattern boresight at a downtilt. The maximum squint level of the antenna is a consistent downtilt off of boresight and which is at the midpoint of the antenna tilt range. The antenna provides a high roll-off radiation pattern through the use of Yagi dipole elements configured in this arrangement, having a beam front-to-side ratio exceeding 20 dB, a horizontal beam front-to-back ratio exceeding 40 dB, and is operable over an expanded frequency range.

Abstract: A television antenna formed from a pair of generally sinuous antenna arms extending outwardly from a common central axis and arranged opposite each other. The antenna arms do not interleave or touch each other. A reflector provides a separation distance between the reflector and the pair of antenna arms.

Abstract: A microstrip fed log periodic antenna has two spaced dipole strips mounted on a ground plane. Each dipole strip has a trunk with a base, tip and alternating arms extending perpendicular to the trunk. One dipole strip includes an integral transmission feed line that extends from the tip, along the trunk of the other dipole strip at constant distance and along the ground plane at a constant distance. The one piece dipole strip with the integral transmission feed line reduces passive intermodulation and simplifies manufacture.

Abstract: A miniature broadband stacked microstrip patch antenna formed by two patches, an active and a parasitic patches, where at least one of them is defined by a Ring-Like Space-Filling Surface (RSFS) being this RSFS newly defined in the present invention. By means of this novel technique, the size of the antenna can be reduced with respect to prior art, or alternatively, given a fixed size the antenna can operate at a lower frequency with respect to a conventional microstrip patch antenna of the same size and with and enhanced bandwidth. Also, the antennas feature a high-gain when operated at a high order mode.

Abstract: Antenna elements that have at least three pairs of coplanar and aligned conducting loops, of approximately one-wavelength to two-wavelength perimeters, that have shapes such that there are corners at the centers and smooth curves or straight lines at the outer edges of each pair of loops. Where the loops of adjacent pairs of loops approach each other, they are connected. Various applications of these antenna elements also are disclosed.

Abstract: Frequency-dependent phase center movement in near-field, unshielded, electromagnetic susceptibility testing using a log-periodic dipole can be significantly reduced by bending the rearmost dipole elements forward. Each bent dipole element has an inner portion and an outer portion connected to each other at a bend, the inner portion extending outward from a boom in substantially perpendicular relation to the boom, and the outer portion extending obliquely outward and forward from the bend. The frequency range of the antenna can be extended by forming each element of the longest dipole with an undulating shape when viewed in a direction along the boom.

Abstract: An antenna having a dual-band driven element and a second antenna element simultaneously produces a directional radiation pattern at an upper frequency and an omnidirectional radiation pattern at a lower frequency. The dual-band driven element is formed as a dipole or monopole with at least one choke connected to the end of the dipole or monopole. In an exemplary embodiment, the dual-band driven element includes a central dipole or monopole that has chokes formed as u-shaped extensions located at the ends of the central antenna dipole or monopole. An antenna array includes the dual-band driven element and a second driven antenna element with a reflector and/or a director in a Yagi-Uda configuration. An antenna array includes the dual-band driven element with a reflector or with a reflector and a director in a Yagi-Uda configuration.

Abstract: An optical antenna collects, modifies and emits energy at light wavelengths. Linear conductors sized to correspond to the light wavelengths are used. Nonlinear junctions of small dimension are used to rectify an alternating waveform induced upon the conductors by the lightwave electromagnetic energy. The optical antenna and junctions are effective to produce harmonic energy at light wavelengths. The linear conductors may be comprised of carbon nanotubes that are attached to a substrate material, which may then be connected to an electrical port.

Abstract: A microstrip fed log periodic antenna has two spaced dipole strips mounted on a ground plane. Each dipole strip has a trunk with a base, tip and alternating arms extending perpendicular to the trunk. One dipole strip includes an integral transmission feed line that extends from the tip, along the trunk of the other dipole strip at constant distance and along the ground plane at a constant distance. The one piece dipole strip with the integral transmission feed line reduces passive intermodulation and simplifies manufacture.

Abstract: A printed circuit log periodic dipole array (LPDA) includes dipole elements with arms having reduced size through use of high effective permittivity substrate portions. The radiation efficiency degradation generally associated with use of a high permittivitty substrate can be reduced through addition of magnetic particles to provide enhanced permeability in the high permittivity regions. The substrate preferably includes meta-materials. The feed line can provide a broadband transformation by being configured as a plurality of segments having quarter wave electrical lengths.

Abstract: A printed circuit array of log periodic dipole arrays (LPDA) where each LPDA includes dipole elements with arms having reduced size through use of high effective permittivity substrate portions. The radiation efficiency degradation generally associated with use of a high permittivitty substrate can be be reduced through addition of magnetic particles to provide enhanced permeability in the high permittivity regions. The substrate preferably includes meta-materials. The feed line can provide a broadband transformation by being configured as a plurality of segments having quarter wave electrical lengths.

Abstract: An antenna system that includes a directional antenna designed to reduce the occurrence of side lobes, thus reducing the possibility of interference with other radio frequencies is disclosed. The directional antenna includes an antenna member and a reflecting tube. The reflective tube is sleeved over the antenna member. The reflective serves to block unwanted radial side lobes. The directional antenna can also include provisions that assist in suspending the antenna member within the reflective tube.

Abstract: A fractal antenna can be incorporated in a hearing device to optimize wireless communication capabilities of such a device. A particular fractal structure having fractals of a generally + shaped geometry can be advantageous when used as a fractal antenna. The fractal antenna is implemented as a conductive trace on a substrate and can be implemented on an integrated circuit in the hearing aid device.

Abstract: The present invention has been achieved with the aim of determining the minimum number of element antennas required to suppress unnecessary sidelobe levels and obtaining a cost reduction effect. An antenna apparatus arranged in accordance with the invention has a plurality of element antennas 1 arranged on a plurality of concentric circles 2 assumed to exist on a plane and differs in radius from each other, and forms a beam in a direction inclined by &thgr;0 at the maximum from a direction perpendicular to the plane.

Abstract: An optical antenna collects, modifies and emits energy at light wavelengths. Linear conductors sized to correspond to the light wavelengths are used. Nonlinear junctions of small dimension are used to rectify an alternating waveform induced upon the conductors by the lightwave electromagnetic energy. The optical antenna and junctions are effective to produce harmonic energy at light wavelengths. The linear conductors may be comprised of carbon nanotubes that are attached to a substrate material, which may then be connected to an electrical port.

Abstract: A non-planar log-periodic antenna feed with low ohmic loss, intermediate gain multioctave bandwidth, and dual polarization can be integrated with a low-noise MMIC amplifier, at ambient or cryogenic temperatures. Long, lossy transmission lines with nearly 1 dB loss, normally required for connecting log-periodic antennas to microwave signal detection circuits, are unnecessary in this design. Amplifiers are positioned close to the antenna terminals at the vertex of the antenna, inside a square pyramidal shield with half the opening angle of the antenna arms. The non-obvious idea is that a conductor enclosing a large volume of self-similar shape between the antenna arms enhances gain while preserving the frequency-independence of the log-periodic antenna over its operating bandwidth. The design has been reduced to practice. A 1-10 GHz prototype has been range tested. A small microwave telescope which incorporates this feed can achieve over multioctave bandwidths an A/T (sensitivity) that is unprecedented.

Abstract: A conductive member may include a conductor having a pair of opposed parallel surfaces and a cable guide arranged inside the conductor. In another embodiment, a conductive member may include a conductive bar having a pair of opposed parallel surfaces and a convex surface connecting respective first ends of the pair of opposed parallel surfaces to one another. An embodiment of a method for forming a conductive member includes forming a cable guide arranged inside a conductor having opposed parallel surfaces, where the cable guide is oriented in a direction substantially parallel to the opposed parallel surfaces. In an embodiment of an antenna, the antenna includes a conductor having a pair of opposed lateral surfaces, and a cable guide arranged inside the conductor and oriented in a direction substantially parallel to that of the opposed parallel surfaces.

Abstract: A self-similar log-periodic antenna is described comprising a plurality of substantially triangular conductive elements, 4, symmetrically disposed in either planar or curved configurations about a central conductive boom to form an antenna arm. Two or more antenna arms are assembled into an antenna by symmetrically locating such antenna arms substantially in the shape of a pyramid (for planar arms) or in a conical shape (for curved arms). Some embodiments include a conductive fin, 5, to reduce cross-polarization coupling between antenna arms. Some embodiments include a grounded conductive shield on the interior of the antenna providing electromagnetic shielding for the interior region of the antenna while preserving the self-similar geometry of the antenna and shield combination.

Abstract: A printed circuit log periodic dipole array (LPDA) includes dipole elements with arms having reduced size through use of high effective permittivity substrate portions. The radiation efficiency degradation generally associated with use of a high permittivitty substrate can be be reduced through addition of magnetic particles to provide enhanced permeability in the high permittivity regions. The substrate preferably includes meta-materials. The feed line can provide a broadband transformation by being configured as a plurality of segments having quarter wave electrical lengths.

Abstract: A printed circuit array of log periodic dipole arrays (LPDA) where each LPDA includes dipole elements with arms having reduced size through use of high effective permittivity substrate portions. The radiation efficiency degradation generally associated with use of a high permittivitty substrate can be be reduced through addition of magnetic particles to provide enhanced permeability in the high permittivity regions. The substrate preferably includes meta-materials. The feed line can provide a broadband transformation by being configured as a plurality of segments having quarter wave electrical lengths.

Abstract: RF and microwave radiation directing or controlling components are provided that may be monolithic, that may be formed from a plurality of electrodeposition operations and/or from a plurality of deposited layers of material, that may include switches, inductors, antennae, transmission lines, filters, and/or other active or passive components. Components may include non-radiation-entry and non-radiation-exit channels that are useful in separating sacrificial materials from structural materials. Preferred formation processes use electrochemical fabrication techniques (e.g. including selective depositions, bulk depositions, etching operations and planarization operations) and post-deposition processes (e.g. selective etching operations and/or back filling operations).

Abstract: An integrated feed broadband dual polarized antenna having a substantially planar support structure and a plurality of symmetrically positioned radiating structures disposed on the first surface of the planar support structure. A plurality of straight, non-interleaving ribs extend substantially perpendicularly from a first and second lengthwise side of each radiating structure. The plurality of straight, non-interleaving ribs extending from the first lengthwise side are complimentary to the plurality of straight, non-interleaving ribs extending from the second lengthwise side of the each radiating structure. Integrated microstrip lines serve as transmission lines to feed. The integrated microstrip lines form an integrated printed circuit infinite balun structure which is inherently frequency independent and provides 180° electrical phase required to feed a 180° rotated radiating structure.

Abstract: Frequency-dependent phase center movement in near-field, unshielded, electromagnetic susceptibility testing using a log-periodic dipole can be significantly reduced by bending the rearmost dipole elements forward. Each bent dipole element has an inner portion and an outer portion connected to each other at a bend, the inner portion extending outward from a boom in substantially perpendicular relation to the boom, and the outer portion extending obliquely outward and forward from the bend. The frequency range of the antenna can be extended by forming each element of the longest dipole with an undulating shape when viewed in a direction along the boom.

Abstract: A self-similar log-periodic antenna is described comprising a plurality of substantially triangular conductive elements, 4, symmetrically disposed in either planar or curved configurations about a central conductive boom to form an antenna arm. Two or more antenna arms are assembled into an antenna by symmetrically locating such antenna arms substantially in the shape of a pyramid (for planar arms) or in a conical shape (for curved arms). Some embodiments include a conductive fin, 5, to reduce cross-polarization coupling between antenna arms. Some embodiments include a grounded conductive shield on the interior of the antenna providing electromagnetic shielding for the interior region of the antenna while preserving the self-similar geometry of the antenna and shield combination.

Abstract: A steerable antenna and method of steering a radio frequency wave received by and/or transmitted from the antenna. The antenna includes a tunable high impedance surface and at least one end-fire antenna disposed on said surface. The method includes varying the impedance of the tunable high impedance surface.

Abstract: An antenna system includes a fractalized element that may be a ground counterpoise, a top-hat located load assembly, or a microstrip patch antenna having at least one element whose physical shape is at least partially defined as a first or higher iteration deterministic fractal. The resultant fractal element may rely upon an opening angle for performance, and is more compact than non-Euclidean ground counterpoise elements or the like. A vertical antenna system includes a vertical element that may also be a fractal, and a vertical antenna can include vertically spaced-apart fractal conductive and passive elements, and at least one fractal ground element. Various antenna configurations may be fabricated on opposite surfaces of a substrate, including a flexible substrate, and may be tuned by rotating elements relative to each other, and/or by varying the spaced-apart distance therebetween.

Abstract: An antenna element that has four coplanar and aligned loops, of approximately one-wavelength to two-wavelength perimeters, that have shapes that are similar to the mathematical curve called a lemniscate. Variations of the basic shape, related combinations of lemniscate and triangular loops, plus applications of the antenna element also are disclosed.

Abstract: An antenna includes at least one element whose physical shape is at least partially defined as a second or higher iteration deterministic fractal. The resultant fractal antenna does not rely upon an opening angle for performance, and may be fabricated as a dipole, a vertical, or a quad, among other configurations. The number of resonant frequencies for the fractal antenna increases with iteration number N and more such frequencies are present than in a prior art Euclidean antenna. Further, the resonant frequencies can include non-harmonically related frequencies. At the high frequencies associated with wireless and cellular telephone communications, a second or third iteration, preferably Minkowski fractal antenna is implemented on a printed circuit board that is small enough to fit within the telephone housing.

Abstract: A planar, phased-array antenna including a nonconductive substantially planar substrate and a transmission line disposed on one surface is disclosed, a segment of the transmission line forming an arc of radius R centered on the antenna axis. A conductive layer on the other antenna surface includes two or more slotted openings, each slotted opening having one end located within a distance R of the antenna axis, such that, when an electromagnetic signal is fed into one end of the transmission line, electromagnetic energy is sequentially coupled into the slotted openings, and a circularly-polarized signal is radiated from the antenna substantially in the direction of the antenna axis. An amplifier or a connector may be electrically connected to one or both ends of the transmission line, or one end of the transmission line may be terminated in an impedance load to form a leaky-wave antenna. The slotted openings may comprise either or both straight and curved segments, and may be of the same or unequal lengths.

Abstract: A cylindrically conformable antenna is formed on a flexible substrate and preferably comprises a complex pattern coupled to a first feedline and, spaced-apart from the complex pattern, a patch that floats electrically. The complex pattern preferably is a fractal pattern, deterministic or otherwise, but need not be a fractal. The shape, size, and position of the patch relative to the complex pattern, as well as the complex pattern itself, produces multiple frequency bands of interest. These bands may be varied by varying the relative parameters associated with the patch and complex pattern. The resultant antenna is substantially smaller than conventional antennas for the same frequency band, has a natural 50 &OHgr; feed impedance and performs substantially as well as larger conventional antennas.

Abstract: An antenna includes at least two planar conductors cooperatingly arranged in a planar configuration having a bifilar spiral winding structure, a log-periodic structure or a sinuous configuration and a frequency-independent reflective backing situated on one axial side of the planar configuration. The backing includes a solid, disk-shaped dielectric substrate having a relatively high dielectric constant, and three mutually perpendicular arrays of elongated dielectric elements at least partially embedded in the solid dielectric substrate. The elongated dielectric elements have a relatively low dielectric constant. The elongated dielectric elements of the three mutually perpendicular arrays are formed as rods, cones and rings.