Disclosed herein is an antenna device including a first metal layer having first and second areas, a coil pattern having first and second terminals, a first wiring pattern connected between the first area of the first metal layer and the first terminal of the coil pattern, and a second wiring pattern connected between the second area of the first metal layer and the second terminal of the coil pattern. The first metal layer, the first wiring pattern, and the second wiring pattern constitute at least a part of a loop antenna.

An antenna with a heater and method for using the same are disclosed. The antenna may comprise: an antenna aperture having a plurality of radio-frequency radiating antenna elements, the antenna aperture having a ground plane and a material for tuning permittivity or capacitance; and a heater structure in thermal contact with the material.

An antenna system is provided comprising first, second, and third loop antennas, each antenna having a respective loop area and spaced apart from the other antennas. The first and third antennas are configured and driven to form a first independent balanced feed point that is substantially isolated from the second antenna, which is configured to be driven from a second balanced feed point. A sum of the first and second respective loop areas, at a sum port in operable communication with the first and second balanced feed points, is substantially equivalent to the third respective loop area. An automatic control system is configured to automatically and independently adjust, via the balanced feed points, at least one of amplitude and phase for at least one of the three loop antennas, to help to substantially maximize suppression of RFI for a sum of signals from the first and second balanced feed points.

A electromagnetic induction wireless communication system including: a magnetic antenna; an electric antenna; a tuning capacitor coupled to the antenna combination configured to tune the antenna combination; a controller configured to control the operation of the communication system; a signal source coupled to the controller configured to produce a communication signal used to drive the magnetic antenna and the electric antenna; a voltage control unit coupled to the signal source configured to produce one of an amplitude difference, phase difference, and an amplitude and a phase difference between the communication signal used to drive the magnetic antenna and electric antenna.

An antenna comprising: a conductive ground plane; a conductive half loop grounded to the ground plane and configured to be fed with a radio frequency (RF) signal; a single, unitary, three-sided, conductive cage positioned so as to cover the half loop; and dielectric mounts disposed between the cage and the ground plane such that the cage is electrically insulated from the ground plane.

A controllable electrical outlet may comprise a resonant loop antenna. The resonant loop antenna may comprise a feed loop electrically coupled to a radio-frequency (RF) communication circuit and a main loop magnetically coupled to the feed loop. The controllable electrical outlet may comprise one or more electrical receptacles configured to receive a plug of a plug-in electrical load and may be configured to control power delivered to the plug-in electrical load in response to an RF signal received via the RF communication circuit. The RF performance of the controllable electrical outlet may be substantially immune to devices plugged into the receptacles (e.g., plugs, power supplies, etc.) due to the operation of the resonant loop antenna. For example, degradation of the RF performance of the controllable electrical outlet may be less when the controllable electrical outlet includes the resonant loop antenna rather than other types of antennas.

An antenna includes a first electrical conductor that is shaped to form a spiral between its first and second ends that remain electrically unconnected such that the first electrical conductor so-shaped is maintained as an unconnected single-component open-circuit having inductance and capacitance. In the presence of a time-varying electromagnetic field, the first electrical conductor so-shaped resonates to generate a harmonic electromagnetic field response having a frequency, amplitude and bandwidth. A second electrical conductor includes a loop portion overlapping at least a portion of the spiral. The second electrical conductor is electrically isolated from the first electrical conductor. A radio frequency transceiver capable of transmitting and receiving electromagnetic energy is electrically coupled to the second electrical conductor.

An antenna having radio-frequency (RF) resonators and methods for fabricating the same are described. In one embodiment, the antenna comprises a physical antenna aperture having an array of antenna elements, where the array of antenna elements includes a plurality of radio-frequency (RF) resonators, with each RF resonator of the plurality of RF resonators having an RF radiating element with a microelectromchanical systems (MEMS) device.

A low-profile loop antenna includes a driven element disposed very close, in some cases within about 0.005 wavelengths (λ) or closer, to a ground plane, while maintaining sizable gain and usable feed point impedance. Width of the driven element varies along its circumference, such that two diametrically opposed portions of the driven element are wider, and therefore have lower impedance, than other diametrically opposed portions of the driven element. The antenna may be configured to achieve a desired feed point impedance. The antenna may be tuned over a wide bandwidth. Metallic objects placed near the center of the antenna loop do not significantly degrade performance of the antenna. A parasitic element may be added to create a circularly-polarized antenna, without significantly increasing the antenna's profile.

A dual resonator antenna device may include a ground plane positioned adjacent a substrate and may include a first aperture and a second aperture exposing the substrate therethrough. The device may also include an antenna feed positioned in the first aperture. A monopole resonator is coupled to the antenna feed and has a portion near at least one edge of the substrate proximate the second aperture and another portion near the substrate and the ground plane in a direction perpendicular to the ground plane. The device may also include a tunable loop resonator within the first aperture and coupled to the antenna feed and the ground plane.