Abstract: A biostimulator, such as a leadless cardiac pacemaker, having a patch antenna integrated into a housing, is described. The housing includes an annular wall that contains electronic circuitry of the biostimulator and provides a ground plane of the antenna. The patch antenna includes a meandering trace embedded in a curved dielectric layer that is mounted on the annular wall. The trace provides a conductor of the antenna and the dielectric layer provides a dielectric substrate of the antenna between the conductor and the ground plane. The electronic circuitry contained within the annular wall is electrically connected to the trace via an electrical feedthrough that passes through the annular wall and the dielectric layer. The electrical feedthrough places the electronic circuitry in communication with the antenna to transmit or receive wireless communication signals from an external device. Other embodiments are also described and claimed.

Abstract: An antenna module includes a dielectric substrate, in or on which a feed element is formed, a dielectric substrate, in which a ground electrode (GND) is formed, and conductive members. The dielectric substrate is disposed opposite the dielectric substrate. When viewed in plan in the direction normal to the feed element, the conductive members are disposed around the feed element. An air layer is formed between the dielectric substrate and the dielectric substrate. The conductive members are formed in the air layer.

Abstract: An antenna array element with dual polarization is provided. The antenna array element includes a multilayer printed circuit board (PCB), a first patch placed on an inner layer of the multilayer PCB, a second patch placed on an upper layer of the multilayer PCB and coupled by electromagnetic field with the first patch, two U slots placed orthogonally on the multilayer PCB layer under the first patch, feedlines placed on one PCB layer under the U slots orthogonally to each other and configured to excite the U slots, ad a plurality of electromagnetic band gap (EBG) elements located in a boundary area of the antenna array element.

Abstract: An antenna device includes: a dielectric substrate having a feed line and a radiation unit provided on a first surface and having a ground conductor provided on a second surface opposite to the first surface; and a pair of second slits that is provided on a side of the radiation unit facing a side to which the feed line is connected and expands in directions away from each other toward the side to which the feed line is connected when the first surface is viewed from above.

Abstract: An antenna device includes a differential-line, a first metal and a second metal. The differential-line includes a first line and a second line. The first metal and second metal are coupled to the first line and second line respectively. The first metal and second metal have different shapes and/or different sizes. The first metal and second metal form symmetric or asymmetric dipole. The first metal and second metal can be disposed on the same plane or different planes, can be electrically insulated and can have a first slot and a second slot respectively. The antenna device can further include a base coupled to the first line and second line. The base can be a daughter board having a front-end module or not. The IC package in daughter board can have different sizes. The daughter board can be offset by different distances and can be coupled to a mother board.

Abstract: An antenna system includes a composite antenna including a first antenna element disposed above a ground plane, the first antenna element being operatively coupled to a first signal source providing a first signal, the first antenna element being configured to radiate the first signal provided by the first signal source; and a second antenna element disposed above the first antenna element, the second antenna element being operatively coupled to a second signal source providing a second signal, the second antenna element being configured to radiate the second signal provided by the second signal source, the first signal and the second signal being adjusted to set a beamwidth and a directivity of a beam pattern of a combined beam radiated by the composite antenna.

Abstract: An antenna unit to be used by being installed so as to face window glass for a building includes a radiating element, a phase control member situated on an exterior-side with reference to the radiating element and configured to control a phase of an electromagnetic wave radiated from the radiating element, and a conductor situated on an interior-side with reference to the radiating element, wherein the phase control member is a member including a dielectric and a plurality of conductor portions.

Abstract: An electromagnetic device includes: a substrate comprising an elongated aperture having an overall length, L, and an overall width, W, as observed in a plan view of the device, where L is greater than W; a dielectric medium comprising a dielectric material other than air disposed on the substrate substantially covering the aperture, the dielectric medium having a cross sectional boundary, as viewed in the plan view of the device, that is symmetrical with respect to an in-plane axis of reflection of the dielectric medium; wherein the device is configured such that a line perpendicular to the overall length L of the elongated aperture and passing through a center point of the elongated aperture is not any in-plane axis of reflection.

Abstract: In one embodiment of the present disclosure, a housing for an antenna system having a plurality of antenna elements defining an antenna aperture includes a chassis portion, and a radome portion configured for coupling to the chassis portion to define an inner chassis chamber, the radome portion having a planar top surface, wherein the radome portion is configured to have equal spacing between the planar top surface and a top surface of each of the plurality of antenna elements defining the antenna aperture.

Abstract: A protective structure, to protect an antenna from damage, is provided. The protective structure includes a body. The body defines one or more prong-receiving apertures in a first surface of the body, wherein through each aperture of the one or more prong-receiving apertures, the body is configured to receive a prong of one or more prongs of the antenna. The body defines a radio frequency (RF) connection aperture extending from the first surface of the body to a second surface of the body, wherein the body is configured to receive a cable through the RF connection aperture to couple a cable connector of the cable to an RF connector of the antenna.

Abstract: An apparatus includes a substrate, first and second transmission lines on the substrate, first antenna elements coupled to a first-first transmission line, and second antenna elements coupled to a first-second transmission line. A first distance between the adjacent first-first and first-second transmission lines is different than a second distance between the first-first transmission line and a second-second transmission line, the second-second transmission line adjacent to the first-first transmission line on an opposite side from the first-second transmission line. At least two antenna elements in the first antenna elements are differently sized.

Abstract: An antenna arrangement for a communication device comprises a top conductive patch comprising at least a first coupling point and a second coupling point coupled to one or more feed circuits carrying a radio frequency (RF) signal to or from the top conductive patch. The RF signal has a first phase in the first coupling point and a second phase in the second coupling point. A first slot extends in the conductive patch between the first coupling point and the second coupling point. The antenna arrangement according enables a desired current distribution to be realized in the antenna in a controlled and systematic manner. A communication device includes such an antenna arrangement.

Abstract: The disclosed swappable antenna component may include a carrier dimensioned to fit to an interior of an overmold window, wherein the overmold window may be overmolded to a gap of a frame of a computing device. Additionally, the swappable antenna component may include an antenna trace disposed in a conductive layer of the carrier to electronically couple to the computing device, wherein the antenna trace may be surrounded by a non-conductive material of the carrier. Various other apparatuses, systems, and methods are also disclosed.

Abstract: An antenna for a wireless communication device, such as a Wi-Fi access point is provided. The antenna includes an electrically conductive radiation structure including a plurality of radially extending radiation slots, each of which has an open outer end at a perimeter of the electrically conductive radiation structure and defines a respective radiation portion of the electrically conductive radiation structure. The antenna includes a feeding network configured to feed an RF signal to the electrically conductive radiation structure, the feeding network includes a plurality of feeding arms configured to feed the RF signal into each radiation portion of the electrically conductive radiation structure for exciting each radiation portion to emit electromagnetic waves.

Abstract: Provided is an electronic device having a multilayer substrate according to an embodiment. The electronic device may include a multilayer substrate on which an antenna is disposed and which includes a front layer, a back layer, a plurality of middle layers, and a plurality of ground layers. The antenna may include a lower patch that is disposed on a layer different from an upper ground among the plurality of ground layers and is electrically connected to the upper ground at a plurality of offset points; and an upper patch disposed spaced apart from the lower patch by a predetermined distance.

Abstract: An antenna package according to an embodiment includes an antenna unit including a radiator, a transmission line extending from the radiator and an antenna ground pad disposed around the transmission line, and a circuit board electrically connected to the antenna unit. The circuit board includes a core layer, a circuit wiring layer disposed on one surface of the core layer, the circuit wiring layer including a signal transmission wiring electrically connected to the transmission line of the antenna unit and a first ground pattern bonded to the antenna ground pad, and a ground layer disposed on an opposite surface facing the one surface of the core layer. The ground layer does not overlap a portion of the antenna ground pad except for a region bonded to the first ground pattern in a planar view.

Abstract: The present disclosure provides an antenna device. The antenna device includes a dielectric element including a first region and a second region, a first antenna disposed on the first region, and a second antenna disposed on the second region. The first antenna and the second antenna are configured to operate in different frequencies. The first antenna and the second antenna are misaligned in directions perpendicular and parallel to a surface of the dielectric element on which the first antenna or the second antenna is disposed.

Abstract: An electronic device may have a first phased antenna array that radiates through a display and a second phased antenna array that radiates through a rear wall. The first array may include a front-facing dielectric resonator antenna and the second array may include a rear-facing dielectric resonator antenna. The front and rear-facing antennas may share a dielectric resonating element. Feed probe(s) may excite a first volume of the dielectric resonating element to radiate through the display and may excite a second volume of the dielectric resonating element to radiate through the rear wall. The dielectric resonating element may have a geometry that helps to isolate the front-facing dielectric resonator antenna from the rear-facing dielectric resonator antenna. The first and second arrays may collectively cover an entire sphere around the device while occupying a minimal amount of volume within the device.

Abstract: A beam-steering antenna system for improving the angular coverage comprises a transmission line comprising a first end and a second end. The antenna system further comprises a plurality of antenna elements selectively coupled to the transmission line for selectively coupling energy within the transmission line to the plurality of antenna elements. Furthermore, the antenna system comprises a power amplifier coupled to the first end of the transmission line configured to couple-in an input signal into the transmission line during a first operating period. Moreover, the antenna system comprises a delay line coupled to the second end of the transmission line configured to reflect a portion of the input signal into the transmission line, thereby providing a reflection signal during a second operating period.

Abstract: An antenna module includes radiating elements that radiate radio waves in a first polarization direction, and a feed conductor that supplies a common radio-frequency signal to the radiating elements. A first radiating element and a second radiating element are disposed adjacent to each other. The feed conductor includes a common conductor, and conductors branching off from the common conductor. The conductors are respectively coupled to the radiating elements. Frequency characteristics of an impedance of the radiating element are different from frequency characteristics of an impedance of the radiating element. Under another condition of a frequency band in which a return loss is less than or equal to a predetermined value is defined as an operable band width in each of the radiating elements, the operable band width of the radiating element partially overlaps the operable band width of the radiating element.

Abstract: Various ring cells are disclosed herein that include a metallic ring patch and a ring slot to transmit or receive radio frequency (RF) signals. The disclosed ring cells use several dielectric layers that are separated by a low-dielectric foam layer upon which the ring patch is positioned. The ring slot is located below the foam layer. An electrically conductive fence formed curved electrically conductive walls or a circular pattern of electrical vias is positioned around the ring slot. Electrical feed lines are used to either supply electrical power to the ring cells or output RF signals that are received by the ring patch.

Abstract: Provided is an electronic device provided with an antenna for 5G communication according to the present invention. The electronic device includes an array antenna which is implemented as a multi-layer substrate inside the electronic device and includes a plurality of antenna elements. Each of the antenna elements of the array antenna comprises: a patch antenna disposed on a specific layer of the multi-layer substrate and configured to radiate a signal applied from a feeder line; a first electronic band gap (EBG) element disposed parallel to the patch antenna on the left or right side of the patch antenna; and a second electronic band gap (EBG) element disposed parallel to the patch antenna on the upper or lower side of the patch antenna.

Abstract: Provided according to an embodiment is a vehicle-mounted antenna system. The antenna system may comprise: a circuit board; a heat sink configured to have an aperture region above the circuit board and be fixed to the circuit board through a fixing portion; and a coupling feed portion configured to be connected to the circuit board and radiate a signal to the aperture region.

Abstract: An antenna device includes a ground plate made of a flat conductor member, and an opposing conductive plate, which is a flat conductor member placed at a predetermined distance from the ground plate and electrically connected to a power supply line, a short-circuit portion provided in a central region of the opposing conductive plate for electrically connecting the opposing conductive plate and the ground plate. An operating frequency is a frequency at which an inductance of the short-circuit portion and the capacitance formed by the ground plate and the opposing conductive plate resonate in parallel. The short-circuit portion has a perimeter part that is short-circuited with the opposing conductive plate. A circuit is arranged in an area surrounded by a part where a short-circuit portion is short-circuited on the opposing conductive plate.

Abstract: Provided is a diversity antenna and an electronic device including the same. The diversity antenna according to various example embodiments includes a plurality of radiation elements having a tubular shape with apertured upper and lower portions, and a connection plate configured to connect the plurality of radiation elements to each other, the plurality of radiation elements is arranged in a vertical direction coaxially, and the connection plate includes an aperture configured to allow a power supply line to pass through.

Abstract: A radome for protecting a radar device is disposed in the transmission path of signals to/from the radar device. The radome includes a shell; a first circuit board disposed at a side of the shell facing a radar device to be protected, and configured with a first inner circuit ring and a first outer circuit ring facing toward the shell; a second circuit board disposed between the first circuit board and the shell, and configured with a second inner circuit ring and a second outer circuit ring facing toward the shell; a first insulation layer disposed between the first circuit board and the second circuit board; and a second insulation layer disposed between the second circuit board and the shell. The first and second inner circuit rings are enclosed with and insulated from the first and second outer rings, respectively, and each of the circuit rings forms a closed loop.

Abstract: An antenna device includes a ground portion including a linear portion connecting a first point and a second point to each other along a first direction parallel to a surface of a substrate, on one side in a second direction orthogonal to the first direction, a power feeding portion provided in a first range including the first point, and an element portion configured to receive power from the power feeding portion and formed in a conductor portion of the substrate that is insulated from the ground portion in a state in which the element portion protrudes from the first range toward the other side in the second direction. The element portion includes a first element portion protruding in the first range toward the other side in the second direction, and a second element portion extending along the first direction from the first element portion toward the second point.

Abstract: A metasurface device includes a ground structure able to have a ground plane function, the ground structure being able to be alternately in an insulating state, wherein it prevents the propagation of the surface wave over the front surface of a substrate so as to prevent the antenna element from radiating, and in a conductive state, wherein the ground structure has the ground plane function, allowing the propagation of the surface wave over the front surface of the substrate from the emission/reception device to the conductive patches, or vice versa, the ground structure being able to change from the insulating state to the conductive state through illumination of the ground structure at a wavelength called a switching wavelength.

Abstract: Dual-polarized ultrawideband antennas and antenna arrays are provided. Fully inverted-L elements (FILEs) can be used as the radiating element in a unit cell antenna, which can be repeated to form an array. The dual-polarized FILE unit cell can include two L-bent elements, which tightly couple to a common shorted via as well as to each other. The same shorted via can be utilized to suppress the well-known common mode resonance.

Abstract: An antenna module includes an antenna structure including ground, first, second, and third radiators. The ground radiator includes a main ground portion and a branch portion extending from one side of the main ground portion. The first radiator located on the one side of the main ground portion includes a feeding terminal. The second radiator is connected to the one side of the main ground portion. The first radiator is located between the branch portion and the second radiator. The main ground portion, the branch portion, and the first and second radiators together form a waveguide structure. The first and second radiators are configured to excite a first high frequency band. The third radiator is located on the one side of the main ground portion, connected to the first radiator, and located beside the branch portion. The first and third radiators are configured to excite a second high frequency band.

Abstract: A broadband linear polarization antenna structure, including a reference conductive layer, a first patch antenna, a second patch antenna, and a feeding portion, is provided. The reference conductive layer includes through holes. A first short pin is connected between the reference conductive layer and the first patch antenna, and a second short pin is connected between the first patch antenna and the second patch antenna. Each feeding portion penetrates the reference conductive layer through the through hole and is coupled to the first patch antenna.

Abstract: A radar module configured for plant monitoring is provided, including: a microwave chip including a radar signal source configured to generate a radar signal; a coupling element connected to the radar signal source by a signal link; and a resonant cavity into which the coupling element projects, the coupling element being configured to couple the radar signal into the resonant cavity, and the resonant cavity being integrated in the microwave chip.

Abstract: A radar sensor includes a housing, cover, and a plurality of transmit and receive antennas. The housing includes a cavity retaining a processing board. The cover defines a radome having a recess into the cavity with two separate and connected areas. The transmit and receive antennas are positioned on the processing board, adjacent to, and separated by a gap from, the recess. The transmit antennas are configured to transmit RF signals through the first area of the recess. The receive antennas are configured to receive RF signals returning through the second area of the recess.

Abstract: A vehicle provided with an antenna according to the present invention comprises: a conical array antenna in which cone radiators are arranged at certain intervals, wherein the cone radiators are provided between a first substrate and a second substrate and have upper portions connected to the first substrate, lower portions connected to the second substrate, and openings at the upper portions thereof; a patch array radiator which is formed on the first substrate and in which metal patches formed to be separated from the top openings are arranged; shorting pins formed so as to electrically connect the metal patches and a ground layer of the second substrate; and a transceiver circuit for controlling a signal to be radiated through at least one of the conical array antennas, thereby improving a signal reception performance in almost any direction of the vehicle.

Abstract: An antenna structure is provided. The antenna structure includes a first insulating substrate, a second insulating substrate, a first antenna, a second antenna, a third antenna, a grounding element, and a feeding point. The first insulating substrate and the second insulating substrate are spaced apart from each other. The first antenna and the second antenna are respectively disposed on two side surfaces of the first insulating substrate. The first antenna has a first line of symmetry, and the second antenna has a second line of symmetry. The first line of symmetry and the second line of symmetry have an angle there-between, and the angle is within a range from 35 degrees to 55 degrees. The third antenna and the grounding element are respectively disposed on two side surfaces of the second insulating substrate. The feeding point is connected to the third antenna and the grounding element.

Abstract: An antenna device includes a dielectric substrate and a plurality of radiating elements that each have a flat profile. A groove, continuous or segmented, is formed in the dielectric substrate to surround the radiating element in plan view. Another groove, continuous or segmented, is formed around another radiating element. The radiating element and the another radiating element are adjacent to one another.

Abstract: An electronic device is provided. The electronic device includes a housing, an antenna structure, a first conductive material, and a second conductive material. The housing may be configured to provide a front surface and a rear surface of the electronic device. The antenna structure includes a printed circuit board positioned in the housing. The printed circuit board includes a first surface configured to face the front surface or the rear surface and a second surface configured to face a direction opposite to the first surface. The printed circuit board includes a first conductive layer, a second conductive layer, and a dielectric. The first conductive layer includes a first antenna element and a second antenna element which are configured so as not to overlap each other when viewed from above the first surface.

Abstract: Provided according to the present invention is an electronic device having an antenna. The electronic device may comprise: a transparent antenna built into a display and configured to emit a signal to the front of the display; and a transmission line for feeding the transparent antenna. The transparent antenna is configured as a rectangular patch rotated at a predetermined angle, and a portion of the left and right-side areas of the rectangular patch may be formed as vertical lines.

Abstract: An antenna and a fabrication method of the antenna are provided. The antenna includes a plurality of sub-antennas arranged in an array. A sub-antenna of the plurality of sub-antennas includes a first substrate and a second substrate that are disposed opposite to each other, a dielectric function layer disposed between the first substrate and the second substrate, a ground metal layer disposed on a side of the first substrate facing towards the dielectric function layer, and a metal connector. The first substrate of each sub-antenna is coplanar with each other, and the second substrate of each sub-antenna is coplanar with each other. A spliced region is formed between adjacent two sub-antennas of the plurality of sub-antennas, and in the spliced region, two first substrates of the adjacent two sub-antennas are connected by the metal connector.

Abstract: The present disclosure reduces a loss of strength of a radio-frequency signal radiated from an antenna module covered with a housing. An antenna module (100) includes a dielectric substrate (130), a driven element (141), and a ground conductor (190). The dielectric substrate (130) has a multilayer structure. The driven element (141) is disposed in or on the dielectric substrate (130). The ground conductor (190) is disposed between the driven element (140) and a mounting surface (132) on which a power supply circuit is mountable. The power supply circuit supplies the driven element (140) with radio-frequency power. The dielectric substrate has at least one groove (150). The at least one groove (150) is separate from the driven element (140) when the antenna module (100) is viewed in plan. The at least one groove (150) extends toward the ground conductor (190) from a layer on which the driven element (140) is disposed.

Abstract: A modular radio frequency (RF) device includes N base units, each including a differential segmented array (DSA) tile with a support board and a two-dimensional (2D) array of electrically conductive tapered projections disposed on the support board. Neighboring pairs of the electrically conductive tapered projections form RF pixels. The N DSA tiles are arranged to form an RF aperture. The N base units are programmed to switch the RF aperture between a first operating mode and a second operating mode. In the first operating mode, the N base units are operated as at least two independent subsets with each subset operating as an RF transmitter or receiver independently of the other subsets. In the second operating mode all N base units coherently combine as a single phased array RF transmitter or receiver.

Abstract: An antenna, an antenna structure and antenna element are disclosed. The antenna includes a radiator structure having four radiators, each located within a different quadrant of a plane. Diagonally opposite radiators form a pair. A first ground strip connects a first radiator of a first pair of the set to a ground conductor. A first signal strip connects a second radiator of the first pair to a first terminal. The first ground strip and the first signal strip are orientable to form a balanced transmission line. A second ground strip connects a first radiator of a second pair of the set to a ground conductor and a second signal strip is connects a second radiator of the second pair to a second terminal. The second ground strip and the second signal strip are orientable to form a balanced transmission line.

Abstract: An antenna module is to be installed in a communication device. The antenna module includes a dielectric substrate that has a multilayer structure, a ground electrode that is disposed in the dielectric substrate, and a first radiating element that has a flat plate shape. The first radiating element has a first surface (a smooth surface) and a second surface (a rough surface) that has a higher degree of surface roughness than that of the smooth surface. The smooth surface of the first radiating element faces the ground electrode.

Abstract: The disclosed distributed monopole antenna may include a first conductive plate and a second conductive plate. The distributed monopole antenna may also include multiple different vias that electrically connect the first conductive plate to the second conductive plate. Still further, the distributed monopole antenna may include an antenna feed electrically connected to at least one of the vias. Various other systems, methods of manufacturing, and wearable electronic devices that implement distributed monopole antennas are also disclosed.

Abstract: Disclosed is an electronic device including: a housing including a first plate, a second plate facing away from the first plate, and a side member surrounding a space between the first plate and the second plate, connected to the second plate or integrally formed with the second plate, and including a first portion comprising a conductive material, wherein the first portion of the side member includes a plurality of through-holes aligned in a first direction substantially parallel to the first plate and a non-conductive material inside the through-holes; a structure disposed inside the space to face the through-holes and including at least one conductive path; and a wireless communication circuit electrically connected to the conductive path. Various other embodiments inferred from the specification are also possible.

Abstract: An antenna system comprising: a ground plane; an antenna radiator separated from and overlapping the ground plane; at least one feed element configured to provide a radio-frequency feed for the antenna radiator; and at least one resonator coupled to the feed element and positioned in a space between the ground plane and the antenna radiator, wherein the antenna radiator is a broadband antenna radiator having a first operational range of frequencies and the resonator is a narrow band resonator having a second range of resonant frequencies that at least partially lie within the first operational range of frequencies.

Abstract: A wearable device includes a ground element, a first radiation element, a second radiation element, a third radiation element, a fourth radiation element, and a fifth radiation element. The first radiation element has a feeding point, and is coupled to a first grounding point on the ground element. A slot region is surrounded by the first radiation element and the ground element. The second radiation element is coupled to a second grounding point on the ground element. The third radiation element is coupled to the second grounding point. The third radiation element and the second radiation element substantially extend in opposite directions. The fourth radiation element and the fifth radiation element are disposed inside the slot region. An antenna structure is formed by the first radiation element, the second radiation element, the third radiation element, the fourth radiation element, and the fifth radiation element.

Abstract: An antenna system mounted in a vehicle, according to the present invention, comprises: a radiator for transferring, through an upper opening, a signal which is applied through a lower opening; a coupling patch disposed on an upper substrate so as to be spaced apart from the upper opening by a predetermined interval so as to enable the coupling of the signal which has been transferred through the upper opening; and a first antenna connected to the coupling patch so as to make surface contact therewith, and comprising a shorting bar for connecting a ground layer of a lower substrate. The antenna system may further comprise, apart from the first antenna, a second antenna disposed in the antenna system.

Abstract: An electronic device including an antenna, according to one embodiment, is provided. The electronic device can comprise: a first radiator in which metal patterns having a predetermined width and length are stacked on different layers of a multi-layer substrate; and a second radiator in which metal patterns having a predetermined width and length are stacked on top of the first radiator. The electronic device can further comprise a transceiver circuit for connecting to any one metal pattern from among the first radiator and the second radiator through a feeding line.

Abstract: To provide a radar device capable of detecting a position of a target in a direction orthogonal to a viewing angle. In a radar device which detects a target by using a radio wave, the radar device includes: a receiving array antenna (receiving array antenna 17) where a plurality of receiving antenna elements (first receiving antenna 17-1 to eighth receiving antenna 17-8) each having a predetermined length in a first direction are arranged to be disposed in a second direction almost orthogonal to the first direction; a dispersion part (dispersion part 31) which is disposed in a vicinity of the receiving array antenna, and dispersion properties of the radio wave change with respect to the first direction; and a detection part (control and process part 15) which detects the position of the target in the first direction based on the radio wave reflected by the dispersion part.