Abstract: A mutual inductance tuning coil component which includes a substrate; and, a loop antenna mounted on the substrate, the loop antenna being positioned proximate to a Near Field Communication (NFC) radiating component of an information handling system, the loop antenna compensating for the radiated energy generated by the NFC radiating component.

Abstract: Antenna arrays with separate resonances and termination networks for multiple millimeter wave frequency bands are provided herein. In certain embodiments, an antenna array includes a first antenna element that receives the first radio frequency transmit signal at an input. The first antenna element has a first resonant mode and a second resonant mode. The antenna array further includes a first termination network connected to the input of the first antenna element and a second termination network connected to the input of the first antenna element.

Abstract: An antenna apparatus includes a ground substrate, a feeding point provided on the ground substrate, a first conductor device of which one end is electrically connected to the feeding point and which has a plate shape being parallel to the ground substrate, a second conductor device which is arranged between the first conductor device and the ground substrate, of which one end is electrically connected to the ground substrate, and which has a plate shape being parallel to the ground substrate and a connecting portion which electrically connects another end of the first conductor device and another end of the second conductor device to each other. A width of the first conductor device is wider than a width of the second conductor device. Lengths of the first conductor device and the second conductor device are ½ of a wavelength of a radio wave for operating the antenna apparatus.

Abstract: An antenna module disposed on a substrate having a first and a second surface opposite to each other includes a microstrip line, a first radiator, a ground radiator and a ground plane. The microstrip line, the first radiator and the ground radiator are disposed on the first surface. The microstrip line includes a first and a second end opposite to each other. The first end includes a first feeding end. The first radiator is connected to the second end of the microstrip line. The ground radiator surrounds the microstrip line and the first radiator and has a first opening and two opposite grounding ends. The first end of the microstrip line is located in the first opening. A gap is formed between each grounding end and the first feeding end. The ground plane is disposed on the second surface. The ground radiator is connected to the ground plane.

Abstract: This invention relates to an antenna system comprising two identical mutually radiation coupled antennas arranged symmetrically with respect to one another, said antennas having a respective antenna connection gate and a network, which is connected at the input side to the antenna connection gates and which is formed from dummy elements, and having a respective antenna path to a network connection gate, said antenna paths being identical to one another and being separately associated with an antenna.

Abstract: A communication system comprising a radio device and a gooseneck device. The radio device may be coupled to a first antenna and a second antenna. A feedline gooseneck device may be coupled to the first antenna. The feedline gooseneck device may include a coaxial cable coupled between the mobile device and the first antenna and a ferrite element positioned along the coaxial cable. The ferrite element is configured to reduce EM interaction between the first and the second antenna. The ferrite element may be one of a plurality of ferrite elements and the feedline gooseneck device may further include a plurality of flexible elements positioned adjacent to each of the plurality of ferrite elements. The system allows for reduction of an amount of electromagnetic interference between the first antenna coupled to the gooseneck and the second antenna.

Abstract: Aspects of the subject disclosure may include, for example, a motorized drive assembly that includes a motor and a drive assembly, where the drive assembly has an axle configured to be disposed through a rotatable substrate of a polarization shifter for a dual-polarized radiating element, the axle being further configured to fasten, at a first end of the axle, to a support structure of the polarization shifter, wherein, when the motorized drive assembly is assembled to the polarization shifter, the motor is controllable to impart rotational forces, via movement of the axle, to the polarization shifter to effect polarization adjusting for the dual-polarized radiating element. Other embodiments are disclosed.

Abstract: The present disclosure includes, in a dual polarized omni-directional antenna and a base station including the same, a plurality of radiating elements disposed to be spaced apart in one direction by the dual polarized omni-directional antenna, and a feed line for providing a feed signal to the plurality of radiating elements, and the plurality of radiating elements include a first radiator for generating one polarization of dual polarization, and a second radiator for generating the other polarization of the dual polarization, respectively, the first radiator is prepared on a first surface, and the second radiator is prepared on a second surface, and a main lobe direction of the first radiator and a main lobe direction of the second radiator are different directions from each other.

Abstract: A patch antenna includes: a substrate; a first radiator disposed on the substrate and having a first shape; a second radiator disposed on the substrate while being spaced a predetermined distance apart from the first radiator, and having a second shape; and a power feeder which supplies a power feed signal to the first radiator, wherein the first radiator includes a first outer edge portion straightly formed in the horizontal direction and second outer edge portions vertically formed from both ends of the first outer edge portion.

Abstract: A patch antenna structure is disclosed. The patch antenna structure includes a radome; a metal substrate disposed on one side of the radome and kept at a distance from the radome, a side wall of the radome facing to the metal substrate connecting with a feeding patch, or a side wall of the metal substrate facing to the radome connecting with a feeding patch; an antenna radiating patch attached to a side wall of the radome facing to the metal substrate, wherein the antenna radiating patch is kept at a certain distance from the metal substrate to maintain the radio frequency characteristics of the patch antenna.

Abstract: An antenna for facilitating remote reading of utility meters is disclosed. The antenna includes a metal rod and a printed circuit board (PCB), both enclosed by an envelope that includes a plastic body and a plastic cap. The plastic body includes a channel for receiving the metal rod. The plastic cap is for covering the plastic body. The PCB includes a dielectric layer located between a first and second metal layers. Secured to the PCB, the metal rod is electrically connected to the second metal layer of the PCB, but not the first metal layer of the PCB.

Abstract: Antenna elements are described that may include a radiator, a feeding portion, a first impedance transformer, a balun, and a second impedance transformer. The first impedance transformer, balun, and second impedance transformer may be disposed above a ground plane of an antenna array to reduce a bulk of the array. The array can also include a dielectric top layer for loading apertures of the antenna array. The antenna elements can also include anomaly suppressors can be provided to cancel common-mode resonances from the radiators.

Abstract: An antenna module and a wireless transceiver device are provided. The wireless transceiver device includes an antenna module. The antenna module includes a circuit board and at least one antenna array. The at least one antenna array defines a midline. The at least one antenna array includes a plurality of antenna elements and a signal feeding line. Each antenna element includes a feeding branch and a radiating portion. The radiating portion is coupling to the feeding branch, and the radiating portion is exposed on the upper surface of the circuit board. The signal feeding line is arranged in the circuit board and is perpendicular to the midline, and the signal feeding line is coupling to the feeding branch. The radiating portion defines an extension line along its extension direction. There is an included angle between the extension line and the midline.

Abstract: An apparatus includes a radio frequency (RF) circuit to transmit or receive RF signals. The apparatus further includes a loop antenna to transmit or receive the RF signals. The apparatus further includes an impedance matching circuit coupled to the RF circuit and to the loop antenna. The impedance matching circuit includes lumped reactive components.

Abstract: In some embodiments, a radio frequency identification (RFID) tag system includes a first strap mounting pad of an RFID antenna component, and a second strap mounting pad of the RFID antenna component, the second strap mounting pad being electrically coupled to the first RFID strap mounting pad. At least one of the first strap mounting pad and the second strap mounting pad may extend diagonally with respect to a wide edge direction of the antenna component, thus making the RFID antenna component configured to receive both a strap that is parallel to a wide edge direction of the antenna component and a strap that is perpendicular to a wide edge direction of the antenna component.

Abstract: According to one embodiment, in a biquad filter, an output terminal of a first integrator is connected to an input terminal in a negative pole side of a second integrator, an output terminal of the first integrator is connected to a first input terminal in a negative pole side of an adder through the inversion amplifier, an output terminal of the second integrator is connected to a second input terminal in the negative pole side of the adder, an input terminal to which an input signal is input is connected to a third input terminal in the negative side of the adder, and an output terminal of the adder is connected to an input terminal in a negative pole side of the first integrator.

Abstract: The disclosure concerns an antenna assembly having a substrate with an antenna radiating element and a ground conductor disposed on the substrate, the ground conductor further characterized by a plurality of ground resonators, wherein a length associated with each of the ground resonators increases as the ground resonators are distanced from the antenna radiating element. Additionally, a coaxial cable is routed around the antenna assembly for configuring the coaxial cable as an additional ground resonator associated with the antenna assembly. The resulting antenna provides wide band performance between 700 MHz and 2700 MHz with improved efficiency compared with conventional antennas.

Abstract: A multiband radiating array according to the present invention includes a vertical column of lower band dipole elements and a vertical column of higher band dipole elements. The lower band dipole elements operate at a lower operational frequency band, and the lower band dipole elements have dipole arms that combine to be about one half of a wavelength of the lower operational frequency band midpoint frequency. The higher band dipole elements operate at a higher frequency band, and the higher band dipole elements have dipole arms that combine to be about three quarters of a wavelength of the higher operational frequency band midpoint frequency. The higher band radiating elements are supported above a reflector by higher band feed boards. A combination of the higher band feed boards and higher band dipole arms do not resonate in the lower operational frequency band.

Abstract: Short, dual-driven groundless antennas are provided. One of the antennas includes a tubular outer conductor, a tubular inner conductor, and an electrical connector that electrically connects an opposite end of the outer conductor to the exterior of the inner conductor. The inner conductor is longitudinally disposed within the hollow axial interior of the outer conductor such that an axial gap exists between the radially inner surface of the outer conductor and the radially outer surface of the inner conductor, and the inner conductor runs at least to the opposite end of the outer conductor. Electrical signals are connected to a driven end of both the outer and inner conductors, where these signals supply power to/from the antenna whenever it is used as a transmitter/receiver, and neither of these signals needs to be connected to an electrical ground.

Abstract: The present disclosure relates to a mounting assembly and a mounting kit comprising such a mounting assembly for a base station antenna, wherein the mounting assembly has first and second connection parts, an effective length therebetween is related to the mechanical tilt of the base station antenna, and the effective length is continuously adjustable. The mounting assembly comprises a connecting rod mechanism having a first pair of connecting rods, a second pair of connecting rods, and a threaded connection device, wherein the threaded connection device connects two relatively movable hinged connection parts, the distance between the two hinged connection parts can be continuously adjusted by screwing the threaded connection device, so that the effective length can be continuously adjusted to realize continuous adjustment of the mechanical tilt of the base station antenna.

Abstract: The present disclosure relates to a plug-in antenna device arranged to be received in a waveguide section. The plug-in antenna device includes one or more dielectric elements arranged in series and spaced apart by connecting members, a top-most dielectric element being arranged as antenna element. When the plug-in antenna device is received in the waveguide section, the dielectric elements are arranged electromagnetically coupled, whereby a radio frequency signal included in a radio frequency band passing to or from the antenna element via the dielectric elements is arranged to be electromagnetically filtered.

Abstract: A mechanical tilt mounting system for a base station antenna includes a fixed pivot that connects the antenna to a support structure. The antenna is rotatable about the fixed pivot. An adjustable control arm has a first end connected to the antenna and a second end connected to the support structure. Extension and contraction of the adjustable arm rotates the antenna about the fixed pivot to change the angle of inclination of the antenna.

Abstract: Embodiments of the present invention pertain to the field of communications technologies and disclose a multi-band antenna and a communications device. The multi-band antenna includes a reflection panel, at least one high-frequency unit, and at least one low-frequency unit. Each high-frequency unit includes a balun structure, a coupling structure, and a radiation arm structure. The balun structure includes two balun sub-structures, the coupling structure includes two coupling sub-structures, and the radiation arm structure includes two radiation arms. The high-frequency unit and the low-frequency unit are disposed on the reflection panel. Each coupling sub-structure is separately electrically connected to one balun sub-structure and one radiation arm. The coupling sub-structure is configured to transmit a signal whose frequency is higher than a preset threshold, and block a signal whose frequency is lower than the preset threshold.

Abstract: A base station antenna includes a remote electronic tilt (“RET”) actuator, a phase shifter having a moveable element and a mechanical linkage extending between the RET actuator and the phase shifter. The mechanical linkage includes an adjustable RET linkage that has a first link that has a first connection element, a second link that has a second connection element and a connecting member that includes at least a third link. The adjustable RET linkage includes at least a first hinge and a second hinge.

Abstract: An apparatus includes circuitry configured to calculate first parameters for determining a structure of a first antenna device based on a specification value set for the first antenna device to be a target of performance evaluation, acquire a communication frequency based on first parameters, calculate an allowable range of deviation of the communication frequency satisfying a specified performance evaluation standard of the first antenna device, determine a structure of a second antenna device as a reference model, and obtain a change amount corresponding to change in the communication frequency in the allowable range of two second parameters having a correlation with each other, and acquire a relational expression of two first parameters of first parameters that correspond to the two second parameters and that have a correlation with each other, and two first parameters based on the change amount and that have the correlation with each other.

Abstract: An antenna structure according to an embodiment of the present invention includes a dielectric layer including a first surface and a second surface which face each other, a first antenna pattern on the first surface of the dielectric layer, the first antenna pattern including a first radiation electrode, and a second antenna pattern on the second surface of the dielectric layer, the second antenna pattern including a second radiation electrode. Radiation gain and efficiency may be improved utilizing both surfaces of the dielectric layer without mutual radiation interruption.

Abstract: A bracket includes a first member having one end joined to a first surface of an enclosure including an antenna, a second member having one end joined to a second surface of the enclosure, and a third member including a first slot joined to another end of the first member and a second slot joined to another end of the second member. In the bracket, the another end of the first member is guided along and moved in the first slot, and the another end of the second member is guided along and moved in the second slot.

Abstract: The invention relates to a method for automatically adjusting a multiple-input-port and multiple-output-port tuning unit. The invention also relates to an apparatus for radio communication using this method. An apparatus for radio communication of the invention comprises: 4 antennas which form a multiport antenna array; 4 feeders; a multiple-input-port and multiple-output-port tuning unit having 4 input ports and 4 output ports; 4 sensing units; a transmission and signal processing unit, which applies 4 excitations to the input ports, one and only one of the excitations being applied to each of the input ports, and which delivers tuning unit adjustment instructions; and a control unit, which delivers one or more tuning control signals to the multiple-input-port and multiple-output-port tuning unit.

Abstract: The disclosure concerns an antenna assembly having a substrate with an antenna radiating element and a ground conductor disposed on the substrate, the ground conductor further characterized by a plurality of ground resonators, wherein a length associated with each of the ground resonators increases as the ground resonators are distanced from the antenna radiating element. Additionally, a coaxial cable is routed around the antenna assembly for configuring the coaxial cable as an additional ground resonator associated with the antenna assembly. The resulting antenna provides wide band performance between 700 MHz and 2700 MHz with improved efficiency compared with conventional antennas.

Abstract: A method and system of instantiating a lightweight re-calibration of a received signal strength (RSS) fingerprint dataset for mobile device indoor navigation. The method comprises, based on RSS parameters acquired from a plurality of mobile devices acquired at a set of positions within an indoor area, accumulating the RSS parameters in accordance with a trained neural network-based RSS fingerprint dataset in a fingerprint database of the indoor area; identifying respective positions of a subset of the set of positions having a variance that exceeds a threshold variance between observed RSS parameters and RSS parameters determined in accordance the trained neural network; and when contiguous positions of the subset are encompassed by a boundary representing a portion of the indoor area, instantiating a re-calibration of the RSS fingerprint dataset for mobile device navigation within the portion of the indoor area.

Abstract: Representative implementations of devices and techniques provide transmit power detection for an antenna of a wireless system having two or more transmit antennas. A correlation is reduced between a transmit signal of the antenna and signals from other antennas.

Abstract: Disclosed herein are various exemplary embodiments of multi-band, wide-band antennas. In exemplary embodiments, the antenna generally includes an upper portion and a lower portion. The upper portion includes two or more upper radiating elements and one or more slots disposed between the two or more upper radiating elements. The lower portion includes three or more lower radiating elements and one or more slots disposed between the three or more lower radiating elements. A gap is between the upper and lower portions such that the upper radiating elements are separated and spaced apart from the lower radiating elements.

Abstract: A transceiving circuit (1, 1?) for contactless communication comprises transmitter means (3) being adapted to generate an electromagnetic carrier signal and to modulate the carrier signal according to transmitting data, and an antenna (5) being connected to and driven by the transmitter means (3) with the modulated carrier signal. At least one impedance-matching capacitor (C1a) is arranged serially to the antenna (5).

Abstract: Methods and apparatus are provided for allowing a transmitter (Tx) to perform antenna selection independently of a receiver (Rx) in a transceiver supporting both transmit diversity and receive diversity. Certain aspects may utilize a cross switch, which may be used in a parallel or cross configuration, to provide for the independent antenna selection, such that the Rx may maintain the ability to operate on the same antenna as the Tx, on another antenna, or on both antennas for enhanced receive diversity. Furthermore, certain aspects may employ additional switching in the baseband domain in an effort to avoid, or at least reduce, switching glitches in the Rx caused by changing the cross switch configuration. In this manner, the Rx need not re-converge upon antenna switching.

Abstract: An active antenna and associated circuit topology is adapted to provide active impedance matching and band switching of the antenna using a shared tunable component. Using a shared tunable component, such as a tunable capacitor or other tunable component, the antenna provides a low cost and effective active antenna solution. In certain embodiments, one or more passive components can be further utilized to design band switching of the antenna from a first frequency to a second desired frequency.

Abstract: A wireless communication terminal according to the embodiment includes a communication module including a circuit board having a plurality of pins; a shield case antenna overlapping with one side of the circuit board, electrically connected to a part of the pins and including a signal receiving unit; and a signal processing unit for processing the received signals. An antenna matching unit for matching impedance between the signal processing unit and an antenna unit, a phase shifter for controlling a phase of the received signal and an amplitude regulator for adjusting amplitude of the received signal are provided between the signal processing unit and the antenna unit.

Abstract: An ultra-wideband (UWB) antenna for wireless communication in proximity to a human body and between devices having no line-of-sight, includes symmetrical radiators disposed on a side of a dielectric layer, and a differential microstrip feeding line disposed on the side and an opposite side of the dielectric layer. The UWB antenna further includes a top dielectric layer disposed over the side of the dielectric layer, a bottom dielectric layer disposed over the opposite side of the dielectric layer, and a top connecting plate disposed on an outer surface of the top dielectric layer. The UWB antenna further includes a bottom connecting plate disposed on an outer surface of the bottom dielectric layer, and an inter-layer connector configured to connect ends of each of the symmetrical radiators to the top connecting plate and the bottom connecting plate, respectively.

Abstract: An antenna tuner is placed between a Power Amplifier (PA) and an antenna. The antenna tuner includes programmable components that can be tuned in order to effect an impedance translation between the antenna and the PA output. In an embodiment, the antenna tuner is adapted dynamically based on changes in the impedance of the antenna. In another embodiment, the antenna tuner is controlled based on measurement of the voltage reflection coefficient S11.

Abstract: A method and apparatus for reducing a length of an antenna (402) involves an arrangement which includes an orthogonal antenna feed. An antenna includes a radiating element (404) with a length extending along an axis (418). The orthogonal feed arrangement permits recovery of a portion of the spatial volume comprising the antenna which is normally used for antenna matching circuitry (406). An end portion of the radiating element is chosen to be helically shaped and includes an RF feed gap. The RF feed gap is coupled to a matching network which includes elongated conductors (412). The matching circuitry is positioned so that the elongated conductors are adjacent to the first end portion and extend in a direction aligned with the axis, but orthogonal to the coils forming the helically shaped end portion.

Abstract: An RF signal input and output to and from a communication unit is extracted to outside of an antenna module before the RF signal is routed through a matching circuit unit and an antenna unit and a variation occurs, and the RF signal is accurately measured and inspected using a high-frequency wave measuring instrument such as a network analyzer. When the characteristics of the antenna unit have fluctuated or been deteriorated after the antenna module has been installed in a communication device, a measure is implemented by connecting an external matching circuit unit or an external antenna unit to a signal extraction unit.

Abstract: A radiating element having a transition from a waveguide to a dipole radiator. The radiating element utilizes the electric field of electromagnetic waves propagating in the waveguide to excite a section of a microstrip transmission line that is collinear with the waveguide's propagation direction. A waveguide septum guides the electric field of the electromagnetic waves into the transmission line and provides impedance matching. The transmission line can be formed on a first side of a dielectric substrate having a ground plane on a second side of the substrate. A first dipole leg is formed by making a ninety degree turn in the transmission line. A second dipole leg is extended from the ground plane and turned opposite from the first dipole leg. The transmission line includes a transformer having stepped or gradual changes in width of the transmission line leading to the dipole to provide additional impedance matching.

Abstract: The present invention encompasses an antenna (12) for use with a radio-frequency identification transponder (10) that performs optimally in free space and near optimally when near a conductive surface. The radio-frequency identification transponder (10) broadly comprises an antenna (12); an integrated circuit (14); a matching circuit (16) interposed between the antenna (12) and integrated circuit (14); and a substrate (18). The antenna (12) is designed with a length so the antenna (12) as a microstrip resonates at a starting frequency and a matching circuit is constructed. The antenna (12) is placed near a conductive surface and the length of the antenna is adjusted until the antenna reactance is approximately the opposite of the integrated circuit reactance.

Abstract: Disclosed are an antenna tuner and a method for adjusting antenna impedance. The antenna tuner includes a reference impedance resistor, a first coupler having an isolated port connected to one end of the reference impedance resistor, a second coupler having an input port connected to an output port of the first coupler and an output port connected to the antenna, and an impedance adjusting device group connected to the second coupler to adjust impedance of the antenna. An impedance controller generates an impedance adjustment control signal according to a first voltage applied to a coupled port of the first coupler, and a second voltage applied to a coupled port of the second coupler to provide the impedance adjustment control signal to the impedance adjusting device group.

Abstract: A magnetic field focusing assembly includes a magnetic field generating device configured to generate a magnetic field, and a split ring resonator assembly configured to be magnetically coupled to the magnetic field generating device and configured to focus the magnetic field produced by the magnetic field generating device.

Abstract: An end-fed sleeve dipole is provided herein with improved impedance match and increased bandwidth by incorporating a ¾-wavelength transformer in the antenna design. The ¾-wavelength transformer is compatible with a number of different choking schemes, including but not limited to, a single ¼-wave choke sleeve, a single ¼-wave choke sleeve with additional ferrite beads, and two or more ¼-wave choke sleeves with or without ferrite beads. In some embodiments, one or more shunt resonators may be used to provide additional impedance compensation.

Abstract: Disclosed herein is an RFID antenna, including, a dipole antenna pattern, and a matching pattern containing a pair of first pattern parts, each part being discretely and protrusively disposed at one side of the dipole antenna pattern and a second pattern part connecting each distal end of the pair of first pattern parts, wherein a ratio of an inner length of the pair of first pattern parts vs an inner length of the second pattern part is substantially larger than 1:8.

Abstract: An RFID antenna comprised of a first arm, load element, and second arm together providing a complex impedance match to one or more load circuits contained within the load element for operation at one or more frequency bands. The load element is comprised of one or more load circuits. Load circuits are further comprised of one or more RFID transponders, energy scavengers, microcontrollers, and associated sensor circuits. The first and second arms are different in length and shape resulting in an asymmetrical antenna structure along the major axis. The first arm, the load element, and the second arm all comprise radiative electromagnetic structures for ultra high frequency and higher bands of operation. Embodiments provide an antenna with Faraday coils located within the arms operating in one or more of low frequency and, high frequency bands.

Abstract: Microstrip patch antenna (46), feed structure (48), and matching circuit (50) designs for an RFID tag (10). A balanced feed design using balanced feeds coupled by a shorting stub (56) to create a virtual short between the two feeds so as to eliminate the need for physically connecting the substrate to the ground plane. A dual feed structure design using a four-terminal IC can be connected to two antennas (46a,46b) resonating at different frequencies so as to provide directional and polarization diversity. A combined near-field/far-field design using a microstrip antenna providing electromagnetic coupling for far-field operation, and a looping matching circuit providing inductive coupling for near-field operation. A dual-antenna design using first and second microstrip antennas providing directional diversity when affixed to a cylindrical or conical object, and a protective superstrate (66). An annular antenna (46c) design for application to the top of a metal cylinder around a stem.

Abstract: A printed dual-band Yagi-Uda antenna is disclosed, which includes a substrate, a first driver, a first director, a second driver and a reflector. The first driver is formed on the substrate, and is utilized for generating a radiation pattern of a first frequency band. The first director is formed at a side of the first driver on the substrate, and is utilized for directing the radiation pattern of the first frequency band toward a first direction. The second driver is formed between the first driver and the first director on the substrate, and is utilized for generating a radiation pattern of a second frequency band. The reflector is formed at another side of the first driver on the substrate, and is utilized for reflecting both the radiation patterns of the first frequency band and the second frequency band toward the first direction.

Abstract: A dipole antenna assembly (100, 200) includes a dipole antenna (10, 30) and a feeding element (20, 40) connecting with the dipole antenna. The dipole antenna includes a radiation portion (12, 32), a ground portion (13, 33) and a circuit (14, 34). The feeding element includes a central conductor (21, 41) soldered on the radiation portion at a first position, and a shielding layer (23, 43) soldered on the ground portion at a second position. The circuit includes one end connecting with the radiation portion at the first position, and another end connecting with the ground position at the second position for impedance matching.