Abstract: A wideband circularly polarized L-shaped monopole slot antenna has a single C-shaped feed. The measured results demonstrate that the antenna has 23% of circular polarization bandwidth (Axial Ratio<3 dB and Return Loss<?10 dB). The monopole slot antenna occupies a half area on the corner of circuit board compared to half-wavelength slot antenna that requires the area at the center of the board. This feature is attractive for compact wireless devices operate at low frequencies in which circuit board floor planning and signal routing are major concerns. The antenna is extremely low cost and does not require any truncation corner, reflector surface and via connection which increase the fabrication cost.

Abstract: Technology is described for a slot antenna. The slot antenna can include a substrate having a metal layer on a first side of the substrate. A feed line can be located on a second side of the substrate. A first polygon shaped slot can be formed in the metal layer of a first side of the substrate. A second polygon shaped slot can also be formed in the metal layer of the first side of the substrate. The second polygon shaped slot can be recessed within a perimeter of the first polygon shaped slot and the second polygon shaped slot and first polygon shaped slot share a common side. Examples of the first and second polygon shapes may include square or diamond shapes.

Abstract: A radiator element for RF transmission and reception over a wide band of frequencies. The radiator element is formed of conductive material on substrate surface of conductive material in the form of a pair of horns extending in opposite directions to distal tips defining the widest distance of a mouth of a cavity. The mouth reduces in cross-section to a narrowest point in between said pair of horns. The resulting radiator element will radiate and receive frequencies between frequencies the distance of the widest point and narrowest point are sized to receive.

Abstract: An exemplary embodiment of a dual band antenna array includes a folded thin circuit board structure with a thin dielectric layer and a conductor layer pattern formed on a first surface of the dielectric layer, the circuit board structure folded in a plurality of folds to form a pleated structure. A first array of radiator structures on the first surface is configured for operation in a first frequency band in a first polarization sense. A second array of radiator structures is configured for operation in a second frequency band in a second polarization sense. A conductor trace pattern is formed on the folded circuit board to carry control signals, DC power and RF signals. Active RF circuit devices are attached to the folded circuit board in signal communication with the conductor trace pattern.

Abstract: An RFID antenna comprising an elongated structure existing along an axis that is long compared to the signal wavelength and including twin ribbon-like feed lines of electrically conductive material, the feed lines being in a common plane and being uniformly laterally spaced from one another, and a plurality of radiating perturbations associated with the feed lines at a plurality of locations spaced along the feed lines, at each location each feed line has its own individual perturbation or portion of a perturbation.

Abstract: A wideband cavity-backed slot antenna includes an enclosure having a slot, a balun located proximate the slot, a feed extending through the enclosure to the balun, and a plurality of coupled lines proximate the balun and distal to a location at which the balun is coupled to the feed.

Abstract: A mobile terminal including a metal case and an antenna structure that can exhibit optimum radiation performance is provided. The antenna structure includes an antenna having a radiation unit for transmitting and for receiving electric waves, a Printed Circuit Board (PCB) to which the antenna is mechanically coupled at one surface thereof and having a power supply unit electrically coupled to the radiation unit, and a case constructed using a metal material within which the PCB is disposed, wherein the case has at least one slot formed in a surface thereof opposite to the surface to which the PCB is fastened and adjacent to the radiation unit.

Abstract: The embodiments described herein are directed to providing a notched antenna element for improving polarization control without sacrificing gain, bandwidth, scan volume, recurring cost, or manufacturability. The notched antenna element includes a base portion comprising a plurality of contiguous first cross-sectional notched antenna elements, each of the plurality of first cross-sectional notched antenna elements configured in an end-loaded structure for increasing polarization stability; and an upper portion coupled to the base portion, the upper portion comprising a plurality of contiguous second cross-sectional notch antenna elements.

Abstract: An ultra wideband antenna includes: a substrate; a grounding unit, installed on the substrate and scooped with a first slot and a first strip hole; a signal feeding unit, installed on the substrate and including a horizontal portion and a vertical portion, in which the horizontal portion is located in the first slot and the vertical portion is located in the first strip hole; a first complementary, separate, circular resonator; and a second complementary, separate, circular resonator, wherein the first complementary, separate, circular resonator and the second complementary, separate, circular resonator are installed in the horizontal portion of the signal feeding unit and are connected with each other.

Abstract: Systems and methods for assembling lightweight RF antenna structures are provided. In one embodiment, the invention relates to a process for forming a lightweight antenna including a process for forming a first feed assembly for the antenna, the process for forming the first feed assembly including providing a flat flexible circuit substrate, providing a formed flexible circuit substrate, applying an adhesive to a plurality of locations on a surface of the flat substrate or the formed substrate, joining the flat substrate and the formed substrate using the adhesive, and heating the joined flat substrate and the formed substrate to bond the substrates.

Abstract: The planar antenna apparatus may include a planar, electrically conductive, patch antenna element having a geometric shape defining an outer perimeter, and a pair of spaced apart signal feedpoints along the outer perimeter of the planar, electrically conductive, patch antenna element and separated by a distance of one quarter of the outer perimeter to impart a traveling wave current distribution. The outer perimeter of the planar, electrically conductive, patch antenna element may be equal to about one operating wavelength thereof. The apparatus may provide dual circular or dual linear polarization. The planar patch element may relate to a full wave loop antenna as a compliment.

Abstract: Electronic devices may be provided with antennas. The antennas may include conductive antenna cavities. Antenna resonating elements may be mounted in the antenna cavities to form cavity antennas. An antenna cavity may be formed from metal structures with curved edges that define a curved cavity opening. A flexible printed circuit substrate may be coated with a layer of metal. Slot antenna structures such as a directly fed antenna slot and a parasitic antenna slot may be formed from openings in the metal layer. The flexible printed circuit substrate may be flexed so that the antenna resonating element forms a non-planar curved shape that mates with the opening of the antenna cavity. A ring of solder may be used to electrically seal the edges of the cavity opening to the metal layer in the antenna resonating element. The curved opening may be aligned with curved housing walls in an electronic device.

Abstract: In one embodiment according to the teachings of the present disclosure, an antenna generally includes a first, second, and third elements. The first and second elements form a first electro-magnetic radiator that is operable to transmit or receive a first signal having a first sense of polarization. The first and third elements form a second electro-magnetic radiator that is operable to transmit or receive a second signal having a second sense of polarization that is different than the first sense of polarization.

Abstract: A bundled leaky transmission line includes a transmission line inside which a signal is transmitted, wherein multiple leaky transmission lines which exchange a radio wave mainly via a slit provided on an outer circumference of the transmission line are bundled, and the leaky transmission lines are bundled together such that the slit which is provided to each of the leaky transmission lines and which gives radio wave directionality to the leaky transmission line is directed in a direction different from each other.

Abstract: A dual-patch antenna includes a ground plane, a first patch plate parallel to and separated from the ground plane by a separation distance, and a second patch plate separated from the ground plane by the separation distance. The first and second patch plates are coplanar and separated by a radiating slot. An excitation probe isolatedly passes through the ground plane and connects to the first patch plate. A first wall connects an edge of the first patch plate to the ground plane. The first wall is located approximately ¼ wavelength of a mid-band operating frequency from the radiating slot. A second wall connects an edge of the second patch plate to the ground plane. The second wall is located approximately ¼ wavelength of the mid-band operating frequency from the radiating slot. The dual-patch antennas may be organized in an array.

Abstract: A method of manufacturing antennas including forming at least one conductive antenna array pattern having an antenna feed network on at least a first relatively flexible substrate and adhering the at least one flexible substrate to at least one first surface of at least one relatively rigid substrate.

Abstract: A plate-shaped radiating element of a shape having at least three planes is formed by bending a metal plate having a substantially rectangular shape. A first slit is provided from a lower edge of the plate-shaped radiating element up to a portion in the vicinity of an upper edge of the plate-shaped radiating element while passing through a center point of the plate-shaped radiating element, and forms plate-shaped dipole elements on both sides thereof. A second slit is provided parallel to the upper edge of the plate-shaped radiating element and forms a folded element on an upper side thereof. Feeding points are provided on both sides of the first slit at the lower edge of the plate-shaped radiating element.

Abstract: An antenna, suitable for battlefield identification use, employs a multifunctional design. A closed-end coaxial line structure with center conductor has slanted slot radiators provided in its outer conductor. The slot radiators excite a pattern between upper and lower disks of a radial waveguide radiator configuration so that horizontal and vertical components reach the disk circumference with a 90 degree phase differential to provide an omnidirectional antenna pattern of circular polarization. Antennas and methods are described.

Abstract: The disclosure provides an antenna used for a portable device. The antenna includes a feed part, a ground part, a bent part, a main body, and an extended part. The main body connects with the feed part and the ground part. The main body further includes several gaps and slots so that the main body is divided into several radiating areas by the gaps and slots. The bent part is extended from the ground part. The extended part perpendicularly connects with the main body.

Abstract: A multiband comformed-slotted-folded dipole antenna (200) having a unitary conformed shape conductor conforming to an internal communication device configuration (400). The antenna can include a folded dipole (203, 205, 209, 206, 204) forming a part of the unitary conformed shape and having a first portion (212 or 213) forming at least one slot in a slotted plane (220) and a second portion (210 or 211) forming at least one slot in a second plane (230) substantially perpendicular to the slotted plane. The at least one slot in the second plane controls high band antenna resonance and a length (209) of a metal portion in the slotted plane controls lower band resonance. Additional embodiments are disclosed.

Abstract: An antenna device includes an antenna radiation portion, a reflection portion and a connecting portion. The reflection portion and the antenna radiation portion are installed in parallel with each other at both ends of the connecting portion respectively, such that the connecting portion is connected to the antenna radiation portion and the reflection portion, and the antenna radiation portion and the reflection portion are formed by integrally bending a metal plate to reduce interferences caused by other external factors, so as to achieve the expected directivity, lower the production cost, and shorten the manufacturing time.

Abstract: In one embodiment, a wide bandwidth, reduced depth transmit/receive antenna array includes unit cells having continuous slots, a transceiver, unbalanced feeds, impedance transformers, and exciters. The continuous slots are formed in a conductive antenna plane, and the transceiver generates and/or receives electrical signals. The unbalanced feeds may be electrically connected between the transceiver and impedance transformers which match the impedance between feed lines and the exciter. They may be located in a plane perpendicular to the direction of propagation of the radiation, and also may be arranged between the conductive antenna plane and a backplane. The exciter spans a continuous slot, and emits and/or receives radiation from the slot. The antenna array is capable of operating without a radome or balun.

Abstract: The invention concerns a system of antennas on the same support. Each antenna is connected to a first port for the emission/reception in a first frequency band, and to a second port for the emission/reception in a second frequency band. The invention consists in a specific dimensioning of the support, such that the difference of the perimetric lengths separating the median points is a function of the half wavelength ?/2 modulo k ?, k positive integer, where ? is the wavelength corresponding to a working frequency fr.

Abstract: A slot antenna is located on a substrate and includes a grounding portion, a radiating portion, and a feeding portion. The grounding portion is positioned on the substrate. The radiating portion is symmetrically octagonal-shaped and defines four trapezoidal-shaped slots on opposite sides. The radiating portion is parallel to the grounding portion. The feeding portion electrically connects the radiating portion to the grounding portion for feeding electromagnetic signals to the slot antenna.

Abstract: A wireless data communication card configured in accordance with an example embodiment of the invention includes a low profile antenna arrangement that does not protrude from the housing of the computing device when the wireless data communication card is inserted into the housing. The low profile design is achieved without compromising the radio frequency (“RF”) characteristics and performance of the wireless data communication card by tuning the antenna arrangement to account for conductive ground structure located within the housing of the computing device. In accordance with one practical embodiment of the invention, the wireless data communication card is compliant with IEEE Standard 802.11(b) and compliant with PCMCIA specifications.

Abstract: An array antenna with high suppression of cross-polarization has rectangular conductor sections, located successively side by side in a first plane, mutually separated by slots of constant width. A backing reflector transverse to said first plane. Feed structures extend through the backing reflector, the feed structures comprising pairs of parallel feed conductors, each pair comprising conductors coupled to the rectangular conductor sections on opposite sides of a respective one of the slots.

Abstract: A multiple-band antenna having first and second operating frequency bands is provided. The antenna includes a first patch structure associated primarily with the first operating frequency band, a second patch structure electrically coupled to the first patch structure and associated primarily with the second operating frequency band, a first slot structure disposed between a first portion of the first patch structure and the second patch structure and associated primarily with the first operating frequency band, and a second slot structure disposed between a second portion of the first patch structure and the second patch structure and associated primarily with the second operating frequency band. A mounting structure for the multiple-band antenna is also provided. The mounting structure includes a first surface and a second surface opposite to and overlapping the first surface.

Abstract: A dual band antenna includes a grounding portion, a connection portion, a radiating portion, a radiating groove and a feeding portion. The connection portion has a top side and a bottom side disposed relatively, and has a first edge side and a second edge side connected to the top side and the bottom side. The bottom side of the connecting portion is connected with the grounding portion. The radiation portion is protruded from the first edge side of the connecting portion and neighboring to the top side of the connecting portion. The radiation groove is disposed on the inside of the connecting portion and neighboring to the second edge side and bottom side of the connecting portion, and has a opening located on the first edge side of the connecting portion. The feeding portion is formed on the connecting portion and neighboring to the opening of the radiation groove.

Abstract: Methods and apparatus for a coincident phase center dual polarized slotline radiator. In one embodiment, a radiator includes, for each of two polarizations in a unit cell: first and second fins to provide an air transition for a signal, the radiator including a throat region between the first and second fins, a microstrip path transitioning to a slotline feed, a slotline split forming a part of the slotline feed to provide signal power division and 180 degree phase shift for rejoinder in the throat of the radiator to launch the signal into free space. In another embodiment, a four port radiator is provided.

Abstract: A surface antenna for mobile use has a flat fiberglass base having a thickness of between 7.62 mm (0.300 in) and 12.70 mm (0.50 in), and at least one radiator on the base. The base is coated with a metal on its face lying the face carrying the antenna radiator. This coating forms a ground plane for the surface antenna, so that it can easily be used at the installation site in or on the mobile object.

Abstract: Recovery of hydrocarbons, such as petroleum products, from a liquid or solid substrate is facilitated by the use of microwave energy to energize and separate molecular bonds between the hydrocarbons and the substrate. A radio frequency (RF) applicator delivers microwave energy to a treatment volume containing an emulsion of a hydrocarbon and a substrate. Delivering the microwave energy to the emulsion facilitates separation of the hydrocarbon and substrate molecules into layers. Hydrocarbons and other products can then be recovered from their respective layers. The treatment volume may be located either above or below ground. The RF applicator may include an antenna body with slots formed substantially parallel to one another in a substantially horizontal orientation. The RF applicator efficiently delivers microwave energy into the treatment volume. Substantially all of the power supplied to the RF applicator is radiated, with very little power reflected internally within the RF applicator.

Abstract: An antenna for an RFID transponder device having a substrate and an RF integrated circuit. The antenna comprises two opposing conductive elements arranged on one side of the substrate and electrically connected to the integrated circuit; and a conductive patch arranged between the elements on the same side of the substrate and not electrically connected to them.

Abstract: The present invention is a planar antenna member configured to introduce electromagnetic waves generated by an electromagnetic-wave generating source into a processing vessel of a plasma processing apparatus, the planar antenna member comprising: a base member of a circular plate shape, made of a conductive material; and a plurality of through-holes formed in the base member of a circular plate shape, the through-holes being configured to radiate the electromagnetic waves; wherein: the through-holes include a plurality of first through-holes which are arranged on a circumference of a circle whose center corresponds to a center of the planar antenna member, and a plurality of second through-holes which are arranged concentrically with the circle outside the first through-holes; a ratio L1/r is within a range between 0.35 and 0.

Abstract: A circularly polarised array antenna (30) is disclosed. A single layer dielectric substrate (36) has a ground plane (32) located on its upper surface of the substrate and covering only part of the upper surface. A plurality of antenna elements (40-54) are also located on said upper surface of the substrate. Each antenna element has a slot element (60-74) formed in the ground plane and a respective loading element (80-94) located within each slot element. The antenna elements being arranged in a regular array where each respective slot element is sequentially rotated in space with respect to adjacent slot elements, and the loading elements generate a perturbation under excitation. A microstrip feed network (100) is located on the underside of the sub-straw to provide excitation to each slot element, and including feeds of different lengths to be electrically sequentially rotated in common with spatial rotation of the slot elements.

Abstract: An RFID reader antenna including: a printed circuit board (PCB) formed as a dielectric substance; a plurality of slot groups, each having a plurality of slots, disposed on a first face of the PCB; a ground face disposed on areas, excluding the plurality of slot groups, of the first face of the PCB; and a feeder formed as a microstrip line with an open end on a second face of the PCB to feed the plurality of slot groups. Because the slots periodically formed on the ground face are fed in series by using the single microstrip line, the RFID reader antenna can reliably recognize a larger area with a simple structure. In particular, the RFID reader antenna can be useful for the bookstands for book management or smart shelves for displaying articles or goods including clothing goods in superstores or hypermarkets through the use of the ILT RFID application.

Abstract: A THz antenna array has a plurality of THz antennae, a THz antenna having a photoconductive region and a first electrode and a second electrode which are arranged interspaced from each other via a spacer region that extends laterally across at least a part of the photoconductive region. In order to simplify the structure and facilitate its production, a lateral region between adjacent THz antennae of the array is not photoconductive. It is especially free from photoconductive material.

Abstract: Compact 24-port and 36-port multiple-input-multiple-output (MIMO) antenna designs and methods of construction based on a cube-like structure are provided. The antennas can be implemented with slot antennas distributed on the edges and faces of cubes. According to various embodiments of the disclosed subject matter, both spatial and polarization diversity can be achieved and average mutual couplings among the ports better than ?20 dB can be achieved providing good channel capacity in MIMO applications. The disclosed details enable various refinements and modifications according to antenna and system design considerations.

Abstract: A multiple-band antenna having first and second operating frequency bands is provided. The antenna includes a first patch structure associated primarily with the first operating frequency band, a second patch structure electrically coupled to the first patch structure and associated primarily with the second operating frequency band, a first slot structure disposed between a first portion of the first patch structure and the second patch structure and associated primarily with the first operating frequency band, and a second slot structure disposed between a second portion of the first patch structure and the second patch structure and associated primarily with the second operating frequency band. A mounting structure for the multiple-band antenna is also provided. The mounting structure includes a first surface and a second surface opposite to and overlapping the first surface.

Abstract: A leaky wave antenna contains a first and a second leaky wave antenna structure back to back against each other. Each antenna structure comprises a dielectric body and an elongated wave carrying structure, such as a slot in a conductive ground plane. In each leaky wave antenna structure the body and wave carrying structure are mutually arranged to radiate a leaky wave from the wave carrying structure through the dielectric body, the leaky wave radiating at a respective angle to the wave carrying structure. The dielectric bodies of the first and second wave antenna structure adjoin each other in a common plane that is at said respective angles to the wave carrying structures of the first and second wave antenna structure respectively, so that the ground planes are at an angle with respect to each other. The respective wave carrying structures run over into each other at said common plane, the antenna comprising a feed arranged to excite waves in both the respective wave carrying structures together.

Abstract: A multiband antenna includes a conductive sheet, a feeding point, and a grounding point. The conductive sheet defines a first slot, a second slot, a third slot, a fourth slot, a fifth slot, a sixth slot, and a seventh slot thereon. The second slot and the third slot extend from a same short side of the first slot and are parallel to each other. The fourth slot, the fifth slot, the sixth slot, and the seventh slot extend perpendicularly from a short side of the third slot away from the first slot in sequence. The feeding point is formed on the conductive sheet at a long side of the first slot away from the third slot. The grounding point is formed on the conductive sheet at a margin of the slots different from the location of the feeding point.

Abstract: A new type of multihole antenna which is mainly suitable for mobile communications or in general to any other application where the integration of telecom systems or applications in a single antenna is important. The antenna includes a radiating element which at least includes one hole. By means of this configuration, the antenna provides a broadband and multiband performance, and hence it features a similar behaviour through different frequency bands. Also, the antenna features a smaller size with respect to other prior art antennas operating at the same frequency.

Abstract: Apparatus for suppressing noise and electromagnetic coupling in the printed circuit board of an electronic device includes an upper conductive plate and an array of conductive coplanar patches positioned a distance t2 from the upper conductive plate. The distance t2 is chosen to optimize capacitance between the conductive coplanar patches and the upper conductive plate for suppression of noise or electromagnetic coupling. The apparatus further includes a lower conductive plate a distance t1 from the array of conductive coplanar patches and conductive rods extending from respective patches to the lower conductive plate.

Abstract: A method for making a horn antenna array includes the steps of making planar boards with surface conductor or metallization defining a plurality of side-by-side horns, and with horn feed conductors extending to an edge of the boards. The edges of the board are metallized in a pattern to define feed pads in contact with the feed conductors. Slots are cut in the boards on the axes of the horns so that two orthogonal boards can be joined together for “radiation” in mutually orthogonal planes. A surface-conducive dielectric support defines surface pads in a pattern that matches the pattern of feed pads in a set of joined boards, and through vias connect from the surface pads to lower layers, which may include a beamformer, for making individual connections to the horns.

Abstract: A mobile wireless communications device may include a portable housing, a circuit board carried by the portable housing and having a ground plane thereon, wireless communications circuitry carried by the circuit board, and an antenna assembly carried by the housing. More particularly, the antenna assembly may include a flexible substrate, an electrically conductive antenna element on the flexible substrate and connected to the wireless communications circuitry and the ground plane, and a floating, electrically conductive director element on the flexible substrate for directing a beam pattern of the antenna element.

Abstract: The present invention in one aspect relates to a circularly polarized antenna having a conductive ground layer, a conductive patch and a dielectric substrate formed between the conductive ground layer and the conductive patch. The conductive patch formed in a square shape with four equal sides and has four square slots with each formed in the central portion of each side, and two rectangular slots orthogonally formed in the central area of the square such that one rectangular slot is aligned with one diagonal of the square, the other rectangular slot is aligned with the other diagonal of the square, and the junction of the two rectangular slots is coincident with the geometrical center of the square.

Abstract: A circuit for communicating information in a wireless network includes a filtering circuit in communication with a zero intermediate frequency (ZIF) transceiver circuit. The filtering circuit includes a first mixer in communication with an output of the ZIF transceiver circuit. The filtering circuit includes a first Surface Acoustic Wave (SAW) filter circuit in communication with an output of the first mixer. The filtering circuit includes a second mixer in communication with an output of the first SAW filter circuit. The filtering circuit includes a third mixer, and a second SAW filter circuit in communication with an output of the third mixer. The filtering circuit includes a fourth mixer in communication with an output of the second SAW filter circuit and an input of the ZIF transceiver circuit. The filtering circuit also includes a local oscillator circuit in communication with the first, second, third and fourth mixers.

Abstract: Antennas are provided for electronic devices such as portable computers. An electronic device may have a housing in which an antenna is mounted. The housing may have an antenna window for the antenna. The antenna window may be formed from dielectric or from antenna window slots in a conductive member such as a conductive wall of the electronic device housing. An antenna may have an antenna resonating element that is backed by a conductive antenna cavity. The antenna resonating element may have antenna resonating element slots or may be formed using other antenna configurations such as inverted-F configurations. The antenna cavity may have conductive vertical sidewalls and a conductive rear wall. The antenna cavity walls may be formed from conductive layers on a dielectric antenna support structure.

Abstract: The present invention relates to a transmission/reception antenna with diversity of radiation comprising on a substrate at least a first and a second radiating elements connected by a network of feeder lines to a transmission/reception circuit of electromagnetic signals, wherein the network is constituted by a first feeder line connected to a first radiating element and by a set of two second feeder lines each connected by means of a switching element to the second radiating element in such a manner as to supply the two radiating elements in phase or in phase opposition, the set of the two second feeder lines being connected to the first feeder line by a third feeder line, the first and third feeder lines being connected by a feeder line common to the transmission/reception circuit of electromagnetic signals.

Abstract: Antenna systems for passive radio-frequency identification (RFID) tags. The antenna systems have a very small form factor with good power harvesting and good performance in proximity to other antennas. The antenna system includes at least one, and preferably two, parallel serpentine antenna elements formed on, or otherwise supported by, an antenna substrate so that a RFID-tag integrated circuit (IC) can be electrically contacted to the antenna system at one end of the antenna substrate. A conducting wire that runs in the same direction as the at least one serpentine antenna element is used to match impedance and enhance antenna performance and power flow between the antenna and the IC. An impedance-matching circuit may be employed in place of the conducting wire to facilitate impedance matching between the antenna and the IC.

Abstract: A slot antenna disposed on a substrate including a first surface and an opposite second surface includes a feeding portion, a first radiation portion, a second radiation portion, and a third radiation portion. The feeding portion is disposed on the first surface, and operable to feed electromagnetic signals. The first radiation portion electronically connected to the feeding portion is circular-shaped and disposed on the first surface. The second radiating portion is disposed on the second surface and defines a slot. The second radiation portion couples the first radiation portion to radiate the electromagnetic signals. The third radiation portion is ring-shaped and disposed on the second surface. The third radiation portion couples the first radiation portion to radiate the electromagnetic signals. The first radiation portion, the second radiation portion, and the third radiation portion respectively radiate electromagnetic signals with different frequencies. The second radiation portion is grounded.