Abstract: An optimal configuration for at least one antenna and/or at least one frequency selective surface is generated. A configuration of elements is generated by selecting a simple configuration of at least one element and applying a genetic algorithm to the simple configuration to generate a configuration optimized for various characteristics. A stochastic process may be used to randomly select an arrangement of elements as the simple antenna configuration and to select elements that connect the randomly selected elements to produce a stochastic configuration to which the genetic algorithm is then applied. Alternatively, an iterated or semi-iterated process may be applied to the simple antenna configuration to produce a fractal or a semi-fractal configuration, respectively, to which the genetic algorithm is then applied. Also, the elements may be optimized independently.

Abstract: Methods and systems are provided for embedding electrical components within a device including a frequency responsive structure, such as an antenna or a frequency selective surface. Electrical components are selected and locations for placing the selected components within the device are selected for optimizing performance characteristics of the structure. The selection may be performed by modeling the device with various electrical components embedded at various locations using, for example, a genetic algorithm. The selected components are embedded at the selected locations. The frequency responsive structure and the selected components embedded at the selected locations may be produced in the same manufacturing process. The selected electrical components may be embedded at the selected locations as contiguous and integral parts of the device and may be embedded within the frequency responsive structure.

Abstract: By configuring a high impedance frequency selective surface (HZ-FSS) structure for the appropriate values of surface impedance (surface resistance and surface reactance), a high frequency artificial ferrite metamaterial can be synthesized with almost any desired value of real and imaginary permeability. Materials with these properties have not previously been physically realizable at frequencies above 1 GHz.

Abstract: By configuring a high impedance frequency selective surface (HZ-FSS) structure for the appropriate values of surface impedance (surface resistance and surface reactance), a high frequency artificial ferrite metamaterial can be synthesized with almost any desired value of real and imaginary permeability. Materials with these properties have not previously been physically realizable at frequencies above 1 GHz.

Abstract: An antenna system includes an antenna element and an electromagnetic bandgap element proximate the antenna element wherein the electromagnetic bandgap element is optimized for narrow bandwidth operation thereby providing radiofrequency selectivity to the antenna system. Preferably the electromagnetic bandgap element is tunable such as through use of a bias-alterable dielectric substrate or other tuning mechanism. The design approach also provides a means of creating an ultra-thin low-profile narrowband tunable channel selective antenna system suitable for low frequency applications.

Abstract: A system for low power chemical sensing can include a voltage shift unit which receives a voltage signal from a chemical sensor unit. The voltage signal can be determined by a concentration of an analyte. The voltage shift unit can transform the voltage signal to an input voltage signal, and send the input voltage signal to a plurality of frequency selective surface (FSS) units of an FSS array. The FSS array can communicate a radio frequency (RF) signal in an Institute of Electrical and Electronics Engineers (IEEE) S band with a resonant frequency based on the input voltage to provide the concentration of the analyte.

Abstract: A frequency selective surface includes a pattern of electromagnetic material formed on a substrate suspendable over a ground plane for reflecting or transmitting electromagnetic waves at one or more particular frequencies. The frequency selective surface may include one or more meandering line inductors and/or one or more interdigitated capacitors formed within the pattern of electromagnetic materials for adjusting the frequencies at which the electromagnetic waves are reflected or transmitted. The frequency selective surface may also or instead include one or more inductors and/or one or more capacitors arranged in series within the pattern of electromagnetic materials to adjust the frequencies at which the electromagnetic waves are reflected or transmitted. In addition, the pattern of electromagnetic materials may be formed within the substrate in such a manner that the frequencies at which the electromagnetic waves are reflected or transmitted are tunable.

Abstract: Examples of the present invention include antennas and scattering elements having a metamaterial cloak configured so as to reduce effects on the operating parameters of a nearby antenna. For example, an antenna has an antenna frequency, and a cloak is disposed around the antenna having a frequency range in which the cloak is operative. The antenna frequency can lie outside the frequency range of the cloak, whereas the frequency of a second antenna lies within the frequency range of the cloak. In this case, the antenna is cloaked relative to the second antenna.

Abstract: Examples of the present invention include metamaterials, including metamaterial lenses, having material properties that approximate the behavior of a material with low (0<n<1) effective index of refraction. Metamaterials may be designed and tuned using dispersion engineering to create a relatively wide-band low-index region. A low-index metamaterial lens created highly collimated beams in the far-field from a low-directivity antenna feed.

Abstract: A reconfigurable frequency selective surface (FSS) includes a plurality of conducting patches supported on the surface of a dielectric layer, with selectable electrical interconnections between the conducting patches so as to provide a desired characteristic. The reconfigurable FSS can be used in a reconfigurable artificial magnetic conductor (AMC). A reconfigurable AMC includes a dielectric layer, a conducting back-plane on one surface of the dielectric layer, and a reconfigurable FSS on the other surface of the dielectric layer. A reconfigurable AMC can be used as a dynamically reconfigurable ground plane for a low-profile antenna system.

Abstract: Examples of the present invention include metamaterials, including metamaterial lenses, having material properties that approximate the behavior of a material with low (0<n<1) effective index of refraction. Metamaterials may be designed and tuned using dispersion engineering to create a relatively wide-band low-index region. A low-index metamaterial lens created highly collimated beams in the far-field from a low-directivity antenna feed.

Abstract: Examples of the present invention include antennas and scattering elements having a metamaterial cloak configured so as to reduce effects on the operating parameters of a nearby antenna. For example, an antenna has an antenna frequency, and a cloak is disposed around the antenna having a frequency range in which the cloak is operative. The antenna frequency can lie outside the frequency range of the cloak, whereas the frequency of a second antenna lies within the frequency range of the cloak. In this case, the antenna is cloaked relative to the second antenna.

Abstract: A method for making an electromagnetic band gap structure includes performing a single full wave simulation for the structure using a computer to perform the simulation, extracting a multiple port scattering matrix based on the single full wave simulation using a computer, and measuring or estimating a transmission of waves across the body between a first port and a second port of the body. The body has multiple ports between the first port and the second port that are defined by scattering elements using the computer. The matrix may be reduced to a two by two matrix recursively one dimension at a time using the computer.

Abstract: A reconfigurable frequency selective surface (FSS) includes a plurality of conducting patches supported on the surface of a dielectric layer, with selectable electrical interconnections between the conducting patches so as to provide a desired characteristic. The reconfigurable FSS can be used in a reconfigurable artificial magnetic conductor (AMC). A reconfigurable AMC includes a dielectric layer, a conducting back-plane on one surface of the dielectric layer, and a reconfigurable FSS on the other surface of the dielectric layer. A reconfigurable AMC can be used as a dynamically reconfigurable ground plane for a low-profile antenna system.

Abstract: An improved frequency selective surface (FSS) comprises a periodically replicated unit cell, the unit cell including a material having a first electrical conductivity in the presence of an external condition, and a second electrical conductivity in the absence of an external condition, or in the presence of a modified external condition. For example, the material may be a chemoresistive material, having an electrical conductivity that changes in the presence of a chemical or biological analyte, i.e. having a first value of electrical conductivity in the presence of the analyte, and a second value of electrical conductivity in the absence of the analyte.