102 results about "Fractal antenna" patented technology

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. A fractal antenna according to the present invention is substantially smaller than its Euclidean counterpart, yet exhibits at least similar gain, efficiency, SWR, and provides a 50Ω termination impedance without requiring impedance matching.

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 Δ, non-planarly or otherwise, preferably ≦0.05λ 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. Resonator systems as well as antenna systems may be tuned using is disclosed methodology.

The invention relates to a rectangular wide-sew porcelain Minkowski fractal antenna used for a radio frequency recognition system, relating to a microstrip antenna. The invention provides the rectangular wide-sew porcelain Minkowski fractal antenna used for a radio frequency recognition system, which has small size, large bandwidth, low return loss and omnidirectional radiation characteristic. A porcelain baseplate is arranged, and both faces of the porcelain baseplate are provided with silver coatings, wherein the silver coating at one face of the porcelain baseplate is provided with a Minkowski fractal antenna radiating patch, the silver coating at the other face of the porcelain baseplate is an antenna grounding layer which is provided with a rectangular wide-sew structure, and antenna feed points are arranged on the Minkowski fractal antenna radiating patch.

A vertical complementary fractal antenna is provided, which includes a first fractal structure and a second fractal structure. The first fractal structure is defined as a superposition over at least one iteration of a motif, while the second fractal structure has a pattern complementary to that of the first fractal structure. Thus, the antenna may effectively increase bandwidth.

A multi-polarized continuous transverse stub (CTS) antenna includes a first feed network operative to at least one of receive or transmit a signal having a first polarization, and a second feed network different from the first feed network and operative to at least one of receive or transmit a signal having a second polarization different from the first polarization. At least one parallel-plate region is defined by a first plate structure and a second plate structure spaced apart from the first plate structure, where a first coupling structure connecting the first feed network to the parallel-plate region and a second coupling structure connecting the second feed network to the parallel-plate region. A common aperture is arranged on one side of the parallel-plate region, wherein wavefronts produced by the first and second coupling structures and propagated within the parallel-plate region radiate to free-space through the common aperture.

This invention relates tone base integrating wave feedback structure super wide antenna in the wireless communication field, which comprises the following parts: input or output ends, micro band feedback unit, antenna unit, gradually change unit, even transmission unit, over hole unit, co-surface waveguide unit and each unit, wherein, four antenna units are in circle shape with even transmission units connected each two and with orderly decreased sizes from outside to center to form branch structure.

An apparatus for estimating a subsurface material property includes: a first energy interface device configured to transmit electromagnetic or electrical energy into the subsurface material; a second energy interface device configured to receive return electromagnetic or electrical energy due to the transmitted electromagnetic or electrical energy interacting with the subsurface material; and a processor configured to estimate the property using a signal received from the second device; wherein at least one of the first energy interface device and the second energy interface device is a fractal-shaped antenna comprising a base motif figure and at least one scaled down replication of the base motif figure, the at least one replication being a change from the base motif by at least one of a linear displacement translation and a rotation, and a position of the replication upon the base motif figure is by at least one of rotation, translation, and stretching.

Compact top-loaded, fractal monopole antenna system embodiments are provided for multi-band airborne operation over ultrabroadband ranges (e.g., 30 to 2000 MHz). These multi-band embodiments are self-contained, aerodynamic and compact (e.g., blade height less than 9.5 inches) and are power efficient with a low return loss (e.g., less than −7 dB). System embodiments include a set of impedance-matching circuits configured to substantially match an antenna impedance to a predetermined system impedance over a set of predetermined frequency bands. In an embodiment, at least one impedance-matching circuit includes a chain of selectable air-core inductors which are novelly arranged to improve radiation efficiency and prevent damage to support substrates. In an embodiment, a lowest-frequency one of the impedance-matching circuits is configured to process signals having a maximum wavelength λ_max wherein a fractal member is configured with a length that does not exceed λ_max/40. System embodiments are configured to respond to a variety of existing radio systems that send commands via different encoding formats.

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.

The invention discloses a terahertz wave generator based on graphene. The teraHertz wave generator comprises a substrate, a graphene film and a terahertz photoconductive antenna, wherein the graphene film is formed on the substrate and the terahertz photoconductive antenna is used for coupling Sierpinski fractal geometrical shape of the terahertz wave. According to the invention, bar-shaped electrodes are arranged at the two ends of inverse fractal antenna; a bias voltage is applied between the electrodes; the graphene film is pumped through femtosecond pulse laser; the electron motion in the graphene film is excited; the terahertz wave is irradiated under the effect of the bias voltage; the terahertz wave is coupled with the free space through the photoconductive antenna. Due to the high electronic mobility and the characteristic of easily generating terahertz wave of the graphene and the coupling function of the photoconductive antenna with similar characteristic, the emission efficiency of terahertz wave is increased, the antenna gain is increased, the power consumption and propagation loss of the antenna are reduced and the radiant power of the terahertz wave is increased.

The invention discloses a partial discharge ultrahigh-frequency detection Peano fractal antenna, wherein the partial discharge detection Peano fractal antenna comprises a dielectric layer and a conductor layer, wherein the conductor layer is laid on the upper surface of the dielectric layer; the conductor layer comprises a plurality of end-to-end bend conductor sections; the conductor sections are arranged according to the Peano three-stage fractal principle so as to form a three-stage radiation antenna element; the covering surface of the conductor layer on the dielectric layer is a rectangular surface; the side length of the covering surface is the side length of the conductor layer; and the conductor sections are provided with feeding points. The Peano fractal antenna provided by the invention has good direction property, is wide in frequency band, has small standing-wave ratio, is convenient for impedance match, and can meet the requirement of transformer partial discharge on-line monitoring ultrahigh-frequency detection.

Using arrangement structure of Koch fractal antenna and triangle locus circled in multiturn designs antenna in multiple frequency with smaller area than area of general structure of antenna. Using arrangement structure of Koch fractal antenna can reduce area needed by inversion F type antenna in dual frequency in order to obtain better utilization.

The invention provides a photo strip-gap ceramics Kontol fractal micro-strip antenna for radio frequency identification system, relates to a micro-strip antenna. The photo strip-gap ceramics Kontol fractal micro-strip antenna for radio frequency identification system has small size, large bandwidth, lower return loss and omnidirectional radiation feature. The micro-strip antenna comprises a ceramic wafer and silver coatings are set on the two surfaces of the ceramic wafer, wherein one silver coating is Kontol fractal wireless radiation patch and another silver coating is rectangular-hole array photo strip-gap structure. The relative dielectric constant of the ceramic wafer is 9+-10%. The shape of the ceramic wafer is rectangle and the side length of the square ceramic wafer is 20mm+-1mm and the length thereof is 1.0mm+-0.05mm. The photo strip-gap ceramics Kontol fractal micro-strip antenna for radio frequency identification system has features of small size, large bandwidth, lower return loss, good omnidirectional radiation feature and easy to integrate. The antenna can satisfy the concrete requirement of a RFID application system to the antenna.

The invention discloses a transformer partial discharge ultrahigh frequency detection Hilbert fractal antenna optimization method. The method includes the following steps: S1, determining a fitness function of a genetic algorithm according to a design object of an ultrahigh frequency antenna, and controlling the search direction of the algorithm; S2, determining structural parameters a, b, and c, of the antenna and an encoding and decoding scheme of (x, y); S3, using each group of structural parameters of the ultrahigh frequency antenna as an individual, and determining a certain number of individuals as an initial population of the genetic algorithm; S4, decoding a binary code of each individual into a structural parameter of the ultrahigh frequency antenna, invoking Ansoft Designer software to perform simulation so as to acquire an electrical characteristic parameter of the antenna, and substituting the calculated standing-wave ratio into the fitness function to calculate the fitness value of the individual; and S5, determining if a design demand of the antenna is met or not according to the returned fitness value of the individual. The invention provides an analysis antenna automatic optimization algorithm which can improve the design ability and efficiency of the antenna, and can acquire a partial discharge ultrahigh frequency detection Hilbert fractal antenna having excellent performance.

A broadband circularly-polarized spidron fractal antenna is disclosed. The broadband antenna of the present invention can realize a bandwidth exceeding 70% without using a multilayer substrate to implement the broadband properties, by forming a geometric structure of a slot, i.e., a spidron fractal, which has not been used in the conventional antennas, on the ground surface of the antenna. The present invention can also induce the radiation properties of a circularly-polarized wave from the properties of the spidron fractal shape, without employing an additional secondary circuit such as a phase distribution circuit for implementing the circularly-polarized wave. Due to such properties described above, the present invention can implement a small broadband circularly-polarized antenna that costs less to manufacture.