Abstract: Disclosed are to a communication terminal and an antenna apparatus thereof. The antenna apparatus includes an antenna device including a feeding point to which a signal is applied; and at least one variable reactance device connected to the antenna device. The communication terminal determines a communication network to access to drive the antenna apparatus corresponding to the determined communication network, and accesses to the determined communication network through the antenna apparatus to communicate. Accordingly, a resonance frequency band of the antenna apparatus is expanded.

Abstract: A communication device includes a ground element and an antenna element. The antenna element includes a first radiation element, a second radiation element, and a control circuit. One end of the first radiation element is coupled to a signal source, and another end of the first radiation element is an open end. The second radiation element includes at least a first portion and a second portion. A first end of the first portion is a shorted end coupled to the ground element, and a fourth end of the second portion is an open end. The second radiation element surrounds the open end of the first radiation element. The control circuit is coupled between a second end of the first portion and a third end of the second portion of the second radiation element. The control circuit provides at least two different impedances.

Abstract: A Radio Frequency (RF) device includes an adjustable antenna structure for coupling to a transmit/receive coupling module. The adjustable antenna structure includes an antenna and a plurality of transmission line elements. At least one of the plurality of transmission line circuit elements is selected, based on a transmission line characteristic signal, to form a transmission line circuit that is coupled to the antenna.

Abstract: A multi-frequency antenna (1) includes a grounding portion (1) extending along a transversal direction; a radiating arm (11) extending along a transversal direction and disposed above the grounding portion; a connecting arm (12) connected to the grounding portion and the radiating arm; a capacitor (13) connected to the radiating portion and the connecting arm; and a cable (15) having an inner conductor connected to the connecting arm and an outer conductor connected to the grounding portion.

Abstract: Disclosed is an antenna device for a portable terminal, including a circuit board having a conductive layer attached on a surface, a first slit formed by partially removing the conductive layer in a position adjacent to one side of the circuit board, the first slit extending in parallel with a lateral periphery of the circuit board, a radiation portion comprising part of the conductive layer positioned on the lateral periphery of the circuit board in one side of the first slit, and a feed line placed on the first slit and adapted to feed the radiation portion from the other side of the first slit. The radiation portion further comprises a second slit extending from the first slit to the lateral periphery of the circuit board across part of the conductive layer forming the radiation portion, and a frequency adjustment element placed on the second slit.

Abstract: An antenna duplexer includes a transmission filter and a reception filter both coupled with an antenna terminal. The transmission filter has a lower pass band than the reception filter. The transmission filter includes a first series resonator coupled with a first terminal, a second series resonator connected to the first series resonator at a first node, a first parallel resonator connected to a first port of the first series resonator, a second parallel resonator connected to a first node and the first parallel resonator at a second node, a third parallel resonator connected to the first node, a fourth parallel resonator connected to the third parallel resonator at a third node, a first inductance element coupled with the second node and a ground, and a second inductance element coupled with the third node and the ground. The second inductance element has a lower inductance than the first inductance element.

Abstract: An antenna apparatus for backscattering an incoming radio frequency (RF) signal includes an antenna for backscattering the incoming RF signal in accordance with a reflection coefficient characteristic of the antenna. A variable impedance circuit includes an output electrically connected to the antenna. A band-pass delta sigma modulator is coupled to the variable impedance circuit and digitally controls the output of the variable impedance circuit, such that the reflection coefficient of the antenna is adjusted based on the digitally controlled output of the variable impedance circuit. In an RFID network, the apparatus and method reduces the effect of DC offset in the reader device and the effects of the reader device's phase noise, while allowing for complex modulations.

Abstract: This application describes a dynamically tuned front end module using a modal antenna approach for improved communication system performance. The front end module consists of power amplifiers, filters, switches and antennas along with tuning circuits integrated and controlled to provide an optimized system for RF transmission. Dynamic tuning provides the ability to maintain optimized system performance for a wide variety of use cases and environments that the wireless device is operated in. Several transmission modes are accessed in an algorithm to optimize the performance of multiple wireless devices in a cellular system, to include a power conservation mode, emergency transmission mode, and cell capacity optimization mode. Dynamic adjustment of correlation and isolation between multiple antennas is a benefit provided by this front end topology.

Abstract: A mobile communication device includes an antenna unit to operate in multiple frequency bands by shifting the resonance frequency of the antenna using capacitors. A first capacitor unit may be formed by the disposal of a first electrode in a hole in a first antenna pattern and the formation of a second electrode in the portion of the first antenna pattern opposing the first electrode. The first capacitor unit may be formed in various ways to be activated by a switch. The connection of the first capacitor unit to a voltage supply and ground may trigger a shift in the resonant frequency of the first antenna pattern.

Abstract: A built-in antenna apparatus for a electronic device is provided. The antenna apparatus comprises a PCB with conductive and non-conductive areas. An antenna radiator is disposed at the non-conductive area of the PCB; the antenna radiator has a feeding portion and at least a first radiating portion configured in a first pattern branched from the feeding portion and has an end portion electrically connected to the conductive area. At least one capacitor is electrically connected in series within the first radiating portion. A resonant frequency of the first radiating portion is a function of a capacitance value of the at least one capacitor. The antenna can be provided in a smaller size for a given frequency band due to the capacitance. A second antenna radiator branched from the feeding portion can also be provided for operation at a different frequency band.

Abstract: A portable electronic device is provided that has a hybrid antenna. The hybrid antenna may include a slot antenna structure and an inverted-F antenna structure. The slot antenna portion of the hybrid antenna may be used to provide antenna coverage in a first communications band and the inverted-F antenna portion of the hybrid antenna may be used to provide antenna coverage in a second communications band. The second communications band need not be harmonically related to the first communications band. The electronic device may be formed from two portions. One portion may contain conductive structures that define the shape of the antenna slot. One or more dielectric-filled gaps in the slot may be bridged using conductive structures on another portion of the electronic device. A conductive trim member may be inserted into an antenna slot to trim the resonant frequency of the slot antenna portion of the hybrid antenna.

Abstract: An electronic device may have an antenna that includes conductive antenna structures forming an antenna resonating element and an antenna ground. A band-stop filter may be coupled between first and second portions of the conductive structures. The band-stop filter may be formed from multiple series-connected resonant circuits. The band-stop filter and an impedance matching circuit may be coupled in series between the antenna resonating element and the antenna ground. The band-stop filter may be characterized by a stop band. The antenna may be configured to operate in a first communications band that is outside of the stop band and a second communications band that is covered by the stop band. The impedance matching circuit may be an adjustable circuit that is used to tune the antenna. The adjustable circuit may be a switch-based adjustable capacitor that is adjusted to tune the response of the antenna in the first communications band.

Abstract: An antenna device and a wireless communication apparatus that are capable of obtaining a plurality of resonant frequencies and varying the plurality of resonant frequencies over a wide range are provided. A first antenna unit of an antenna device includes a feed electrode, a first radiation electrode, and a first frequency-variable circuit. The first frequency-variable circuit includes first and second reactance circuits each including a variable-capacitance diode. A control voltage is applied to the first frequency-variable circuit, and the resonant frequency of the first antenna unit can thus be varied. A second antenna unit includes the feed electrode, a second radiation electrode, and a second frequency-variable circuit. The second frequency-variable circuit includes first and third reactance circuits each including a variable-capacitance diode. A control voltage is applied to the second frequency-variable circuit, and the resonant frequency of the second antenna unit can thus be varied.

Abstract: An antenna circuit includes a substrate, an antenna, and a projected artificial magnetic minor (PAMM). The antenna is fabricated on the substrate and is positioned in a region of the substrate that has a high permittivity. The PAMM produces an artificial magnetic conductor at a distance above a surface of the substrate to facilitate a radiation pattern for the antenna.

Abstract: Radiation electrodes are formed on a dielectric base body of an antenna chip. A capacitive feeding electrode is formed on a first end surface of the dielectric base body. A ground electrode, a feeding circuit connection electrode, feeding lines, a tip electrode, and the like are formed on the top surface of a base member of a substrate. When a first switching element selects the feeding line side, a second switching element is made to enter a conducting state. In this state, the radiation electrodes are capacitively fed. When the first switching element selects the feeding line side, the second switching element is made to enter an open state. In this state, the radiation electrodes are directly fed. In this manner, the directivity direction of an antenna can be switched using a single radiation element.

Abstract: An antenna duplexer includes a transmission filter and a reception filter both coupled with an antenna terminal. A pass band of the transmission filter is lower than a pass band of the reception filter. The transmission filter includes a first series resonator coupled with a first terminal, a second series resonator connected to the first series resonator at a first node, a first parallel resonator connected to a first port of the first series resonator, a second parallel resonator connected to a first node and the first parallel resonator at a second node, a third parallel resonator connected to the first node, a fourth parallel resonator connected to the third parallel resonator at a third node, a first inductance element coupled with the second node and a ground, and a second inductance element coupled with the third node and the ground. The first and second parallel resonators and the first inductance element produce an attenuation pole at a frequency lower than a pass band of the transmission filter.

Abstract: A communication device includes a communication circuit part, a transmission path for signals, a ground, a coupler electrode, and a resonance part. The coupler electrode includes an upper flat part as an electrode, a support, and a connecting portion. The support supports the upper flat part. Thus, the upper flat part faces the ground and is separately placed therefrom at a height only enough to ignore the wavelength of the signal, while having a flexible portion which is elastically deformable in the height direction. On the connecting portion, the other end of the support is connected to the transmission path. The resonance part enlarges a current flowing into the coupler electrode through the transmission path. A micro dipole is a line segment connecting between the center of accumulated electric charge in the coupler electrode and the center of mirror charge accumulated in the ground.

Abstract: An antenna is provided having a good matching characteristics when immersed in a fluid such as saline water, oil, or other liquids (“the phantom liquid”). In some embodiments, the antenna provides a tight capacitive coupling with the phantom liquid through the use of a higher permeability cover and absence of a gap between the cover and the antenna body. One embodiment employs a tunably capacitively loaded inverted “F” antenna structure. Additional embodiments of the invention provide an antenna tuning system that saves power by utilizing very low duty cycle periodical refreshing charge at a tuning varactor diode coupled to the antenna.

Abstract: Embodiments provide multi-band, compound loop antennas (multi-band antennas). Embodiments of the multi-band antennas produce signals at two or more frequency bands, with the two or more frequency bands capable of being adjusted and tuned independently of each other. Embodiments of a multi-band antenna are comprised of at least one electric field radiator and at least one monopole formed out of the magnetic loop. At a particular frequency, the at least one electric field radiator in combination with various portions of the magnetic loop resonate and radiate an electric field at a first frequency band. At yet another particular frequency, the at least one monopole in combination with various portions of the magnetic loop resonate and radiate an electric field at a second frequency band. The shape of the magnetic loop can be tuned to increase the radiation efficiency at particular frequency bands and enable the multi-band operation of antenna embodiments.

Abstract: A communication device includes a communication circuit unit processing a high-frequency signal, a transmission path connected to the communication circuit, a ground, a coupling electrode supported so as to face the ground and to be separated by a height negligible with respect to a wavelength of the high-frequency signal, a resonating unit increasing a current flowing into the coupling electrode via the transmission path, and an extended section formed of a conductor disposed near a front of the coupling electrode with an angle ? formed relative to a direction of a microdipole being approximately 0 degree, the microdipole being formed of a line segment connecting a center of charges stored in the coupling electrode and a center of mirror-image charges stored in the ground, the conductor extended in a lateral direction approximately orthogonal to a propagating direction of an electric-field signal occurring from the front of the coupling electrode.

Abstract: A communication apparatus and a method used by the communication apparatus to perform magnetic-field communication with an external apparatus is provided. The communication apparatus determines the communication distance between the communication apparatus and the external apparatus based on the voltage level of a radio signal, a distance measuring device, or other means. The communication distance is compared to a predetermined distance and the communication apparatus dynamically adjusts its resonance frequency for improved magnetic-field communication with the external apparatus.

Abstract: A method of offsetting a mismatch due to user interaction when handling a portable wireless terminal in which antenna matching is changed from inductive matching to capacitive matching in response to a reactance change exceeding a threshold level and vice versa when an opposite change is detected. An antenna interface module (44) is coupled between a RF output or input stage (25 or 33) and an antenna (48 or 50). The antenna interface module includes first and second switches (SW1/1, SW1/2 or SW2/1, SW2/2), a first matching circuit including an inductive reactance (68 or 96) coupled between the power amplifier and the first switch and a second matching circuit including a capacitive reactance (68 or 92) is coupled between the RF output or input stage and the second switch (SW1/1 or SW2/1).

Abstract: An adjustable integrated circuit antenna structure includes an antenna, a ground plane, a plurality of transmission line circuit elements and a coupling circuit. The coupling circuit is operable to couple at least one of the plurality of transmission line circuit elements into a transmission line circuit based on a transmission line characteristic signal. The transmission line circuit has at least one of a bandwidth, an impedance, a quality factor, and a frequency band in accordance with the transmission line circuit characteristic signal.

Abstract: An antenna including a capacitive element and an inductive element having first and second ends, the first end of the inductive element being galvanically connected both to a feed point and to the capacitive element at a first connection point, the second end of the inductive element being galvanically connected to the capacitive element at a second connection point, the second connection point being spatially displaced from the first connection point, wherein electrical signals at the first and second connection points are mutually out of phase.

Abstract: A compact and low-cost antenna device in which no interference occurs even when many antenna units corresponding to various systems are mounted close together in a small area, and a wireless communication apparatus including the antenna device. An antenna device includes plural antenna units mounted on a single dielectric base. A first antenna unit having a lowest fundamental frequency is disposed at a left end of a non-ground region, a second antenna unit having a highest fundamental frequency of the plurality of the antenna units is disposed at a right end of the non-ground region, and a third antenna unit having a fundamental frequency between those of the first antenna unit and the second antenna unit is disposed between the first and second antenna units. A current-density control coil is connected between a first radiation electrode and a power feeder of the first antenna unit, while a reactance circuit is disposed in the middle of the first radiation electrode.

Abstract: A chassis-excited antenna apparatus, and methods of tuning and utilizing the same. In one embodiment, a distributed loop antenna configuration is used within a handheld mobile device (e.g., cellular telephone). The antenna comprises two radiating elements: one configured to operate in a high-frequency band, and the other in a low-frequency band. The two antenna elements are disposed on different side surfaces of the metal chassis of the portable device; e.g., on the opposing sides of the device enclosure. Each antenna component comprises a radiator and an insulating cover. The radiator is coupled to a device feed via a feed conductor and a ground point. A portion of the feed conductor is disposed with the radiator to facilitate forming of the coupled loop resonator structure.

Abstract: A communication system includes the following elements: a transmitter including a transmission circuit unit configured to generate an RF signal for transmitting data and an electric-field-coupling antenna configured to transmit the RF signal as an electrostatic field; a receiver including an electric-field-coupling antenna and a reception circuit unit configured to receive and process the RF signal received by the electric-field-coupling antenna; and a surface-wave propagation medium configured to provide a surface-wave transmission line to transmit a surface wave emanating from the electric-field-coupling antenna of the transmitter with low propagation loss.

Abstract: There is provided an antenna device including a substrate, an earth section which is disposed on a portion of the substrate, a feed point which is disposed on the substrate, a loading section disposed on the substrate and constructed with a line-shaped conductor pattern which is formed in a longitudinal direction of an elementary body made of a dielectric material, an inductor section which connects one end of the conductor pattern to the earth section, and a feed point which feeds a current to a connection point of the one end of the conductor pattern and the inductor section, wherein a longitudinal direction of the loading section is arranged to be parallel to an edge side of the earth section.

Abstract: A multi-band tunable antenna is implemented on device, where the multi-band tunable antenna supports both VHF and UHF frequencies at the same time, and particularly digital television frequencies. The multi-band tunable antenna includes a tunable component that connects metallic radiating elements. Changing the electrical property, such as capacitance, of the tunable component, changes the ability to receive particular frequencies.

Abstract: An antenna device comprising an antenna element disposed on a mounting board separate from a main circuit board, a coupling means disposed on the mounting board such that it is electromagnetically coupled to the antenna element, and a frequency-adjusting means disposed on the mounting board such that it is connected to the coupling means, the antenna element comprising first and second strip-shaped antenna elements integrally connected for sharing a feeding point, the second antenna element being shorter than the first antenna element; the coupling means being formed on a dielectric chip attached to the mounting board, and having a coupling electrode electromagnetically coupled to part of the first antenna element. The frequency-adjusting means comprises a parallel resonance circuit comprising a variable capacitance circuit and a first inductance element, and a second inductance element series-connected to the parallel resonance circuit.

Abstract: A magnetic and/or magneto-electric antenna that has a plurality of conducting loops where each individual loop can be resonated at a frequency that is offset from the frequency of the other loops to provide a composite band-pass response that is broader than that of the individual loops. A receiving circuit acts to sum the signals from each of the antennas to provide a combined frequency response that is broader in bandwidth than any of the individual loops. Similarly a combination of multiple transmitter loops where a transmit circuit drives a common transmit waveform to each of the combined antennas to provide a combined transmitter frequency response that is broader in bandwidth than any of the individual loops.

Abstract: A multi-band antenna comprising a conductive structure and a plurality of current probes coupled around the conductive structure is disclosed. An existing antenna capable of generating H fields having a first signal line is converted into a multi-signal line antenna with increased frequency capabilities, by mounting a first current probe having a designated frequency range about a periphery of the existing antenna; coupling a second signal line to the first current probe; and performing at least one of transmitting and receiving via at least one of the first and second signal lines, wherein the mounting of the first current probe to the existing antenna improves a voltage standing wave ratio (VSWR) of the existing antenna and the second signal line operates as an independent signal line for signal reception/transmission within the designated frequency range.

Abstract: When first and second housings are in an open state, first and second switches are electrically opened, and thus, a first antenna element and a ground conductor operate as a first dipole antenna, and a second antenna element and the ground conductor operate as a second dipole antenna with isolation from the first dipole antenna by the slit. When the first and second housings are in the closed state, the first and second switches are electrically closed, and thus, the first antenna element operates as a first inverted F antenna on the ground conductor, and the second antenna element operates as a second inverted F antenna on the ground conductor with isolation from the first inverted F antenna by the slit.

Abstract: A multi-frequency antenna (1) includes a grounding portion (1) extending along a transversal direction; a radiating arm (11) extending along a transversal direction and disposed above the grounding portion; a connecting arm (12) connected to the grounding portion and the radiating arm; a capacitor (13) connected to the radiating portion and the connecting arm; and a cable (15) having an inner conductor connected to the connecting arm and an outer conductor connected to the grounding portion.

Abstract: An antenna element has first and second feed ports, and is simultaneously excited through the feed ports so as to simultaneously operate as first and second antenna portions respectively, associated with the feed ports. The antenna element is excited at one of a first frequency and a second frequency higher than the first frequency. An antenna apparatus is provided with: a slit that provides isolation between the feed ports; a trap circuit that allows the slit to provide isolation at the first or second frequency when the antenna element is excited at the first or second frequency; and a reactance element that shifts a frequency at which the slit provides isolation between the feed ports, to the first frequency, when the antenna element is excited at the first frequency.

Abstract: A communication system includes the following elements: a transmitter including a transmission circuit unit configured to generate an RF signal for transmitting data and an EFC antenna configured to transmit the RF signal as an electrostatic field or an induced electric field; a receiver including an EFC antenna and a reception circuit unit configured to receive and process the RF signal received by the EFC antenna; and an impedance snatching unit configured to make an impedance of the EFC antenna of the transmitter equal to an impedance of the EFC antenna of the receiver. The RF signal is transmitted by electric-field coupling between the EFC antennas, facing each other, of the transmitter and the receiver.

Abstract: An adjustable integrated circuit antenna structure includes an antenna, a ground plane, a plurality of transmission line circuit elements and a coupling circuit. The coupling circuit is operable to couple at least one of the plurality of transmission line circuit elements into a transmission line circuit based on a transmission line characteristic signal. The transmission line circuit has at least one of a bandwidth, an impedance, a quality factor, and a frequency band in accordance with the transmission line circuit characteristic signal.

Abstract: A multi-frequency antenna (1) comprises a dielectric substrate (100), an antenna element (110), a shunt inductor (120), a capacitor conductor (130), a series inductor (140), a grounded part (150) and a feeding point (160). The antenna element (110) is arranged on the substrate (100), and is electrically connected to the grounded part (150) through the shunt inductor (120). Moreover, the antenna element (110) is electrically connected to the feeding point (160) through a series capacitor formed by a part where the antenna element (110) faces the capacitor conductor (130) and the substrate (100) therebetween, and through the series inductor (140).

Abstract: An object of the invention is to stabilize the convergence operation at the automatic impedance matching time and ensure the reception quality in the convergence process in a fading environment in a radio communication apparatus which performs automatic impedance matching between an antenna and a Radio frequency section to decrease the impedance matching loss, for example, when the apparatus is brought close to a human body.

Abstract: An adjustable integrated circuit antenna structure includes a plurality of antenna elements, a coupling circuit, a ground plane, and a transmission line circuit. The coupling circuit is operable to couple at least one of the plurality of antenna elements into an antenna based on an antenna structure characteristic signal, wherein the antenna has at least one of an effective length, a bandwidth, an impedance, a quality factor, and a frequency band in accordance with the antenna characteristic signal. The ground plane is proximal to the plurality of antenna elements. The transmission line circuit is coupled to provide an outbound radio frequency (RF) signal to the antenna and receive an inbound RF signal from the antenna.

Abstract: An apparatus, such as an antenna assembly, can include a flexible dielectric sheet, a first flexible conductor coupled to the flexible dielectric sheet, a second flexible conductor coupled to the flexible dielectric sheet, a matching section electrically coupled to the first and second conductors, and a hollow dielectric housing having a curved interior surface. The first and second flexible conductors can be sized, shaped, and laterally spaced a specified distance from each other to provide a specified input impedance corresponding to a specified range of operating frequencies for use in wireless information transfer between the antenna assembly and a satellite. The first and second flexible conductors can be located along the curved interior surface of the hollow dielectric housing following an arc-shaped path along the curved interior surface.

Abstract: A communication system includes the following elements: a transmitter including a transmission circuit unit configured to generate an RF signal for transmitting data and an electric-field-coupling antenna configured to transmit the RF signal as an electrostatic field; a receiver including an electric-field-coupling antenna and a reception circuit unit configured to receive and process the RF signal received by the electric-field-coupling antenna; and a surface-wave propagation medium configured to provide a surface-wave transmission line to transmit a surface wave emanating from the electric-field-coupling antenna of the transmitter with low propagation loss.

Abstract: A communication system includes a transmitter including a transmission circuit unit that generates an RF signal for transmitting data and an electric-field-coupling antenna that transmits the RF signal as an electrostatic field, a receiver including an electric-field-coupling antenna and a reception circuit unit that subjects an RF signal received by the electric-field-coupling antenna to reception processing, and a surface-wave propagating means for providing a surface wave transmission line made of a conductor that propagates a surface wave radiated from the electric-field-coupling antenna of the transmitter along a surface of the surface wave transmission line.

Abstract: A micro-strip antenna includes an L-shaped coupler, a set of micro-strip antennas, and an L-shaped band-stop filter. The set of micro-strip antennas includes at least one rectangular micro-strip antenna unit and a micro-strip line. The rectangular micro-strip antenna unit is coupled to the micro-strip line. The micro-strip line is coupled to the first end of the coupler. The band-stop filter is disposed along a corner of the rectangular micro-strip antenna unit, and is disposed between the antenna unit and the coupler without being physically connected to the antenna unit and the coupler. The width, length, and position of the L-shaped band-stop filter can be determined for the specific band-stop frequency and to optimize its coupling extent with the L-shaped coupler.

Abstract: A method of offsetting a mismatch due to user interaction when handling a portable wireless terminal in which antenna matching is changed from inductive matching to capacitive matching in response to a reactance change exceeding a threshold level and vice versa when an opposite change is detected. An antenna interface module (44) is coupled between a RF output or input stage (25 or 33) and an antenna (48 or 50). The antenna interface module includes first and second switches (SW1/1, SW1/2 or SW2/1, SW2/2), a first matching circuit including an inductive reactance (68 or 96) coupled between the power amplifier and the first switch and a second matching circuit including a capacitive reactance (68 or 92) is coupled between the RF output or input stage and the second switch (SW1/1 or SW2/1).

Abstract: In an antenna that has high sensitivity to frequencies of narrow bands and over a wide band and that can be small-sized, and in a wireless module, wireless unit and wireless apparatus using this antenna, the antenna is comprised of a transmission line, and variable capacitance means connected to this transmission line, and the variable capacitance means controls the resonant frequency.

Abstract: A planar antenna includes a ground plane on a substrate, a radiating element coupled to the ground plane on the substrate, and a feed line. An impedance tap point is defined by a connection between the feed line and the radiating element and the length of the radiating element defines the resonant frequency of the antenna. A first portion of the radiating element includes an impedance adjustment mechanism for defining the impedance tap point of the antenna and consequently the impedance of the antenna. A second portion of the radiating element includes a frequency adjustment section which adjusts the length of said radiating element and consequently the resonant frequency of the antenna.

Abstract: A distributed load monopole antenna system is disclosed that includes a monopole antenna including a radiation resistance unit, a current enhancing unit, and a conductive mid-section. The radiation resistance unit is coupled to a transmitter base and the radiation resistance unit includes a radiation resistance unit base that is coupled to ground. The radiation resistance unit also includes a plurality of windings of an electrically conductive material wherein each winding includes an elongated portion that is substantially parallel with an elongated central axis of the monopole antenna. The elongated portions are positioned at a plurality of angularly disposed locations around the elongated central axis of the monopole antenna. The current enhancing unit is for enhancing current through the radiation resistance unit, and the conductive mid-section is intermediate the radiation resistance unit and the current enhancing unit.

Abstract: In an antenna structure having an effect of capacitance in serial connecting, mainly a metallic planar antenna is provided thereon at least with a first metallic plane board, and a second metallic plane board being close to but not connected to the first metallic plane board to form the effect of capacitance in serial connecting. And more, the antenna structure further has an extension arm made from a microstrip extended from the antenna or the second metallic plane board, and can be optionally grounded or not grounded, for the purpose of adjusting the impedance value of the antenna structure.

Abstract: An antennal arrangement for radio signals includes two loop antennas. Each of the antennas is provided with a capacitor. The antennas are separated from one another by a gap and are coupled to each other by a conductor.