735results about "Resonant antenna details" patented technology

A non-contact wireless communication apparatus and a mobile terminal apparatus are provided. The non-contact wireless communication apparatus includes a non-contact wireless communication antenna, a resonance capacitor, connected in parallel with the non-contact wireless communication antenna, for obtaining a predetermined resonance frequency with the non-contact wireless communication antenna, a resonance frequency adjustment unit for changing a resonance capacitance of the resonance capacitor to adjust the resonance frequency, a capacitance change amount control unit for controlling a change in resonance capacitance of the resonance capacitor in the resonance frequency adjustment unit, a resonance frequency shift unit for shifting the resonance frequency of the non-contact wireless communication antenna, and on/off control unit for performing on/off control of the resonance frequency shift unit in accordance with the amount of change in resonance capacitance of the resonance capacitor by the capacitance variation control unit.

The present invention provides an antenna for multiple bands employing a single antenna element 10, capable of operating in multiple frequency bands, and ideal for size reduction purposes. One end A of an antenna element 10 is electrically connected to a feeding point 12 and intermediate points B and C and the other end thereof is electrically connected via switches SWb, SWc, and SWd to a ground conductor 14. The electrical lengths of the antenna element 10 from the terminal to the intermediate points B and C plus connection lines from these points via the switches SWb and SWc to the ground conductor 14 and the electrical length from the one end A to the other end D plus a connection line from the other end via the switch SWd to the ground conductor 14 are set to be capable of resonating different desired frequency bands. By closing one of the switches SWb, SWc, and SWd, one of the desired frequencies can be selected and the antenna can resonate with that frequency. Thus, the antenna employing the single antenna element 10 can operate in multiple frequency bands.

The present invention relates to a dual-band omnidirectional antenna for wireless LANs. The antenna has a planar dielectric substrate, and first and second conductive patterns. The planar dielectric substrate has two parallel surfaces. The first conductive pattern is arranged on one surface of the substrate, and is provided with a first feeder line arranged on a longitudinal central line of the substrate and a plurality of radiating elements connected to the first feeder line and designed such that some of them operate in a high frequency band (4.9 to 5.85 GHz frequency band), and others thereof operate in a low frequency band (2.4 to 2.5 GHz frequency band). The second conductive pattern is arranged on the other surface of the substrate, and provided with a second feeder line arranged on a longitudinal central line of the substrate and a plurality of radiating elements connected to the second feeder line arid up-down symmetrically arranged with respect to the radiating elements on the first conductive pattern.

The present disclosure relates to a method and an antenna for transmitting/receiving a RF signal at a plurality of different frequencies. Transmitting/receiving a RF signal at a plurality of different frequencies is achieved by providing a F antenna comprising a plurality of switches which can be used to adjust the resonant frequency of the antenna. By providing a F antenna, the antenna will be much smaller than the wavelength at which the antenna is operating. This allows the antenna to be used in compact devices such as PDA's and cellular phones.

A slot 2 is defined by notching a conductor plate 1, a first radiation conductor 3 and a second radiation conductor 4 are disposed by sandwiching the slot 2 as a boundary, a third radiation conductor 5 connected to either of the first radiation conductor 3 or the second radiation conductor 4 is provided in the slot 2, if necessary, on and after third radiation conductors, for example, a fourth and fifth radiation conductors connected to either of the first radiation conductor 3 or the second radiation conductor 4 are provided, a power is supplied in the slot by the use of conductor edges of at least two radiation conductors, if required, whereby two monopole antennas and slot antennas, which use respective electric currents on the first radiation conductor 3 and the second radiation conductor 4, are electrically formed, besides, antennas other than that described above are electrically formed by utilizing electric currents over on and after the third radiation conductors.

An antenna having a driven element coupled to multiple additional elements to resonate at multiple frequencies. A magnetic dipole mode is generated by coupling a driven element to a second element, and additional resonances are generated by coupling additional elements to either or both of the driven or second element. One or multiple active components can be coupled to one or more of the coupled elements to provide dynamic tuning of the coupled or driven elements.

An antenna comprising at least one dipole, the dipole comprising a pair of arms drooping relative to a plane orthogonal to a central axis, end portions of the arms being bent back toward the central axis. In one form of the invention the arms are bent back toward the central axis in at least one plane which is parallel to the central axis, and in another form of the invention the dipole arms are bent in the same rotational direction out of a pland which includes the central axis.

An antenna device for a portable radio communication device adapted for receiving radio signals comprises an internal radiating element (10) comprising at least one feeding portion (21, 22) connected to a receiver circuit (40). The radiating element (10) comprises an electrical impedance (30) that is controllable in dependence on the desired frequency range of the received signals, wherein the feeding portion (21, 22) is connected to a feeding input (40a, 40b) on the receiver circuit and the control input of the controllable electrical impedance (30) is connected to an output (40c) on the receiver circuit (40) intended for the control of the VCO resonance frequency of the receiver circuit. In that way an antenna device can be provided inside the casing of a small sized portable radio communication device, which has good performance throughout a narrow sub-band of a frequency band having a relatively low frequency, wherein the narrow sub-band can be adjusted in frequency so as to cover the entire frequency band, such as the FM radio band.

The present invention is to provide an arrangement for giving a planar antenna added strength in construction, which comprises a grounded metal element on bottom of a dielectric substrate of the planar antenna and a curved radiating metal member above the dielectric substrate including two integral radial supports bent and extended downward, wherein one support has one end electrically connected to circuitry in the dielectric substrate for serving as a feed point, and the other support has one end passed the dielectric substrate to connect to the grounded metal element for serving as a ground terminal, so as to prevent the planar antenna from being easily deformed.