Abstract: An anti-radiation mosquito net includes a mosquito net body and a grounding connection device, wherein the mosquito net body is made of silver fibers and has a dense mesh structure; the grounding connection device is connected with the mosquito net body; and the grounding connection device is connected with a socket to lead static electricity of the mosquito net body into the ground. The mosquito net body has a dense net structure made of silver fibers, which has good conductivity, can better shield electromagnetic radiation and protect human body from electromagnetic wave interference; and when the grounding connection device of the mosquito net body is connected with the socket, the functions of anti-electromagnetic radiation and anti-static electricity can be enhanced by leading charges into the ground; according to the physiological process that silver fibers block bacteria, the mosquito net body can play a high-strength antibacterial role at the same time.

Abstract: A vacuum cleaner includes a housing, a debris chamber defined within the housing, and a motor assembly connected to the housing and operable to generate airflow through the debris chamber. The motor assembly includes a motor, an impeller, an impeller housing, and a controller. The impeller is connected to the motor and operable to generate airflow upon operation of the motor. The impeller housing is constructed of an electrically-conductive material. The impeller is positioned within the impeller housing. The controller includes a circuit board assembly. The circuit board assembly including a common circuit, and the impeller housing is electrically connected to the common circuit.

Abstract: An ultrasonic probe coupling assembly (1) and an ultrasonic probe mechanism are disclosed. The ultrasonic probe coupling assembly (1) includes a probe sleeve (11) and a solid-state coupling member (12). The probe sleeve (11) is sleeved on an ultrasonic probe (2). The solid-state coupling member (12) is fixed in the probe sleeve (11). One side of the solid-state coupling member (12) is located in the probe sleeve (11) for fitting to the ultrasonic probe (2), and the other side is protruded from the probe sleeve (11) to be in contact with the skin. The ultrasonic probe mechanism includes the ultrasonic probe coupling assembly (1) and the ultrasonic probe (2).

Abstract: A heat generating component is mounted on a circuit board housed and fixed in a case including a base and a cover. Heat generated from the circuit board is transferred from a back surface of the circuit board via an insulating sheet to a heat transfer base portion formed on an inner surface of the base. Protruding portions configured to press the circuit board through elastic bodies are formed on an inner surface of the cover. When a peripheral portion of the circuit board is in pressure contact with and sandwiched between base-side and cover-side hold portions, curvature deformation of the peripheral portion of the circuit board occurs in a downward direction. Before start of the curvature deformation, the elastic bodies are brought into abutment against a front surface of the circuit board to suppress a reduction in pressure contact force on the insulating sheet.

Abstract: An electronics thermal conduction package is provided. The package may include a housing and an interior space, or envelope, configured to receive a printed circuit board assembly (“PCBA”) with one or more microprocessors or other heat generating elements. The package can be elastically deformed to open a dimension of the envelope, or receiving cavity, such that a complete PCBA can be inserted inside the interior space of the package. Once inserted, the package may be returned to its undeformed, or substantially undeformed, state such that surfaces in the interior space of the package contact one or more of the heat generating elements on the PCBA creating a conductive thermal path from the heat generating elements to the housing of the package.

Abstract: A high frequency electrical connector includes a housing with first and second rows of contacts therein. The housing includes a base and a mating tongue extending forwardly from the base. Each contacts has a contacting section exposed upon the mating surface of the mating tongue, a connection section exposed out of the base, and a middle section therebetween. The first row of contacts as well as the second row of contacts includes a plurality of grounding contacts. First and second shielding plates stacked with each other and commonly between the first row of contacts and the second row of contacts. The first shielding plate has two rows of spring tangs in pairs wherein each pair of spring tangs commonly contact the same grounding contact.

Abstract: A high frequency electrical connector includes a housing with first and second rows of contacts therein. The housing includes a base and a mating tongue extending forwardly from the base. Each contacts has a contacting section exposed upon the mating surface of the mating tongue, a connection section exposed out of the base, and a middle section therebetween. The first row of contacts as well as the second row of contacts includes a plurality of grounding contacts. First and second shielding plates stacked with each other and commonly between the first row of contacts and the second row of contacts. The first shielding plate and the second shielding plate form corresponding spring tangs offset from each other in the front-to-back direction to respectively contact the first grounding contacts and second grounding contacts at different positions in the front-to-back direction.

Abstract: An electronic component mounting package includes a body portion which accommodates an electronic component; a flexible substrate. The body portion comprises a notched portion which is open to a lower surface and a side surface thereof, and is provided with a projecting ridge portion which extends along a side end portion of the notched portion on a side surface side of the notched body portion. The flexible substrate extends from an interior of the notched portion to an exterior of the notched portion, and comprises a fixed end portion joined to a terminal of a coaxial connector disposed on a bottom surface of the notched portion, and a free end portion extending to the exterior of the notched portion. The flexible substrate abuts on the projecting ridge portion to be bent.

Abstract: A polymer layering process that encapsulates and protects electronics components with complex and imprecise geometries. The protective layering process provides a combination of a flexible mold and/or a rigid mold that apply close-forming, encapsulating the polymer layers to the electronic components and precision assemblies. Polymer layer protective jackets are shaped to as-populated circuit boards and assemblies, providing tightly fit barriers with fine resolution accommodating imprecise geometries. The protective jackets can be formed in rigid, semi-rigid, or highly flexible polymer films, to protect the circuitry from the elements, CTE mismatches, shock and vibration loads and extreme g-forces.

Abstract: The present disclosure describes a mechanical chassis having one or more conductive regions separated by one or more non-conductive regions. When a magnetic field contacts, or is sufficiently proximate to, this communication device, the magnetic field induces one or more eddy currents that flow in one or more closed loops around a surface of the one or more conductive regions. The one or more non-conductive regions confine the one or more eddy currents to the one or more conductive regions. The magnetic fields generated by these one or more eddy currents are weaker than a magnetic field generated by eddy currents in a communication device having a mechanical chassis constructed entirely of conductive material.

Abstract: Cables incorporating discontinuous shielding elements are described. A cable may include at least one twisted pair of individually insulated conductors, and a shield element may be positioned adjacent to the at least one twisted pair. The shield element may include a plurality of segments positioned along a longitudinal direction of the cable. Each segment may include a respective dielectric substrate with electrically conductive material formed on the substrate, and each segment may be electrically isolated from the other segments. A respective overlap may be formed between adjacent segments along a shared longitudinal edge. Additionally, a jacket may be formed around the at least one twisted pair and the shield element.

Abstract: A booklet storage includes a first storage member that includes a first receiver portion and a second receiver portion connecting with the first receiver portion; and a second storage member that includes a third receiver portion and a fourth receiver portion connecting with the third receiver portion, wherein the first storage member and the second storage member together receive a booklet in combination, and wherein a first width between the first receiver portion or the second receiver portion and the third receiver portion and a second width between the first receiver portion or the second receiver portion and the fourth receiver portion are different from each other.

Abstract: Provided is a method for manufacturing an electromagnetic interference (EMI) shielding film, including: (a) providing a single insulating layer on a first protective film, the insulating layer being made of an insulating layer composition including at least one resin selected from a thermoplastic resin and a thermosetting resin and at least one filler selected from a flame-retardant filler and an abrasion-resistant filler; (b) providing a metal layer on the insulating layer; (c) providing a conductive adhesive layer on the metal layer, the conductive adhesive layer being made from a conductive adhesive layer composition including at least one resin selected from a thermoplastic resin and a thermosetting resin and a conductive filler; and (d) providing a second protective film on the conductive adhesive layer, and an EMI shielding film manufactured by the method.

Abstract: An electromagnetic interference shield having a main enclosure and optionally at least one auxiliary enclosure. The auxiliary enclosure and the main enclosure have an interior that is continuous with each other. The auxiliary enclosure is made of elastic Faraday material. The outer layer and inner layer may be transparent to view the electronic device. An auxiliary cable with filtering mechanisms may be provided inside a sleeve to allow access and transfer of data from the electronic device while still in the main enclosure.

Abstract: Printed circuits may be electrically and mechanically connected to each other using connections such as solder connections. A first printed circuit such as a rigid printed circuit board may have solder pads and other metal traces. A second printed circuit such as a flexible printed circuit may have openings. Solder connections may be formed in the openings to attach metal traces in the flexible printed circuit to the solder pads on the rigid printed circuit board. A ring of adhesive may surround the solder connections. The flexible printed circuit may be attached to the rigid printed circuit board using the ring of adhesive. An insulating tape may cover the solder connections. A conductive shielding layer with a conductive layer and a layer of conductive adhesive may overlap the solder joints. The conductive adhesive may connect the shielding layer to the metal traces on the rigid printed circuit board.

Abstract: An electromagnetic interference shield enclosure with an extended edge defining a sleeve, the enclosure and sleeve having an outer protective layer and an inner shielding layer to shield electronic devices from electromagnetic interference. The outer layer and inner layer may be transparent to view the electronic device. A magnet system may be provided to allow the device to be operated while in the enclosure. The auxiliary cable with filtering mechanisms may be provided inside the sleeve to allow access and transfer of data from the electronic device while still in the enclosure.

Abstract: An electromagnetic interference shield having a main enclosure and at least one auxiliary enclosure. The auxiliary enclosure in the main enclosure and an interior that is continuous with each other. The auxiliary enclosure is made of elastic Faraday material. The outer layer and inner layer may be transparent to view the electronic device. An auxiliary cable with filtering mechanisms may be provided inside a sleeve to allow access and transfer of data from the electronic device while still in the main enclosure.

Abstract: An electromagnetic shielding method includes the steps of disposing a flexible electromagnetic shielding film including a laminate of at least an insulating layer and a conductive metal layer to cover a portion to be electromagnetically shielded on a printed wiring board so that the insulating layer faces the printed wiring board, the conductive metal layer having a higher melting temperature than that of the insulating resin layer; and heating the electromagnetic shielding film to a temperature to melt and contract the insulating layer, thereby bonding the conductive metal layer to a grounding conductor of the printed wiring board and electrically connecting the conductive metal layer to the grounding conductor. The heating temperature is higher than the melting temperature of the insulating layer and lower than the melting temperature of the conductive metal layer.

Abstract: An electronic control unit is configured in such a way that the groove-shaped concave portion of the second case member includes a first concave portion, in which a groove width at a bottom surface side is narrow, and a second concave portion, in which a groove width at an aperture surface side is wide, and the first concave portion and the second concave portion are linked by an inclined step portion in such a way that a groove width at the step portion is increased in a direction from the bottom surface side to the aperture surface side, and moreover, a tip of the rail-shaped convex portion of the first case member is fitted into the first concave portion at the bottom surface side of the second case member.

Abstract: An apparatus comprises an electrically conductive sheet material having a transparency. The sheet material being flexible to fold to form a pouch configured to enclose a portable computing device. The sheet material is configured to seal side edges of the pouch with edges of the sheet being in electrical engagement. A sealing member is configured to close an opening of the pouch to enclose the portable computing device within the pouch. The closure member is further configured to create an electrical engagement across the opening of the pouch in which the closed pouch structure mitigates electro-magnetic pulse damage and radio waves in general to the enclosed portable computing device, enables viewing of displays of the enclosed portable computing device, and enables manipulation of controls of the enclosed portable computing device while allowing access through wireless to the outside world.

Abstract: An electrical assembly having controlled impedance signal traces and a portable electronic device comprising an electrical assembly having controlled impedance signal traces are provided. In accordance with one embodiment, there is provided a portable electronic device, comprising an electrical assembly, comprising: a chassis made from a conductive material and forming a first ground plane; a first dielectric substrate layer overlaying the chassis; a first signal trace overlaying the first dielectric substrate layer; and a second dielectric layer overlaying the first signal trace.

Abstract: A cabinet includes a chassis and an electromagnetic interference (EMI) shielding apparatus. The shielding apparatus includes a bracket installed to a first end of the chassis, a shaft rotatably installed in the bracket, and a shielding member reeled about the shaft. The shielding member includes a first end fixed to the shaft, and a second end opposite to the first end and forming a holder. A second end of the chassis forms a latch opposite to the bracket for engaging with the holder. The shielding member is made of EMI shielding material, and the shielding member is wound on or let out from the shaft as the shaft rotates.

Abstract: An electromagnetic noise suppression sheet obtained by using combination of a conductive carbon and spinel ferrite particles having a cumulative 50% volume particle diameter of 1 to 10 ?m, can exhibit an excellent transmission attenuation power ratio and a reduced return loss in a near electromagnetic field, and is suitable for high-density mounting. The electromagnetic noise suppression sheet of the present invention can be produced by the process of the present invention which includes the steps of applying a coating material in which the conductive carbon and the spinel ferrite particles having a cumulative 50% volume particle diameter of 1 to 10 ?m are dispersed, to form a coating film having a thickness of 10 to 100 ?m after dried, and subjecting the resulting coating film to thermoforming under pressure.

Abstract: An electromagnetically shielded enclosure with operable interfaces that is portable and lightweight. The electromagnetically shielded enclosure has operable interfaces including a tactile interface through the shielding material and optionally a shielded tactile window for viewing of a secured electronic device and also for operating the secured electronic device should it have a touch screen. An internal frame is optionally provided that prevents conductive interference of a secured electronic device touch screen by the shielded tactile window. An input/output assembly is further provided to allow signals and power to be brought in or out of the enclosure to connect with the secured electronic device without compromising radio silence.

Abstract: A cabinet includes a chassis and an electromagnetic interference (EMI) shielding apparatus. The shielding apparatus includes a bracket installed to a first end of the chassis, a shaft rotatably installed in the bracket, and a shielding member reeled about the shaft. The shielding member includes a first end fixed to the shaft, and a second end opposite to the first end and forming a holder. A second end of the chassis forms a latch opposite to the bracket for engaging with the holder. The shielding member is made of EMI shielding material, and the shielding member is wound on or let out from the shaft as the shaft rotates.

Abstract: Electromagnetic interference shielding structures and methods of shielding an object form electromagnetic radiation at frequencies greater than a megahertz generally include providing highly doped graphene sheets about the object to be shielded. The highly doped graphene sheets may have a dopant concentration greater than >1e1013 cm?2, which is effective to reflect the electromagnetic radiation or a dopant concentration of 1e1013 cm?2>n>0 cm?2, which is effective to absorb the electromagnetic radiation.

Abstract: An electromagnetic interference shield having a main enclosure and at least one auxiliary enclosure. The auxiliary enclosure in the main enclosure and an interior that is continuous with each other. The auxiliary enclosure is made of elastic Faraday material. The outer layer and inner layer may be transparent to view the electronic device. An auxiliary cable with filtering mechanisms may be provided inside a sleeve to allow access and transfer of data from the electronic device while still in the main enclosure.

Abstract: Contactless payment cards with on-card microchips are transported in mailers with RF shielding. The RF shielding is designed to prevent communication with and skimming of information from the contactless cards enclosed in the mailers while in transit.

Abstract: This patent application is associated with the provisional patent applications No. 61/634,254 and No. 61/634,255 which claims the filing date of Feb. 27, 2012. This patent application is for a device which can be described as a pocket liner (and pad) designed to protect individuals from close contact to electromagnetic exposure when they carry (or using) their electronic devices close to their bodies. Studies have shown that exposure to excess electromagnetic radiation has harmful effects to humans. This device is designed to protect the user from those effects by significantly reducing exposure to electromagnetic energy from personal electromagnetic devices with minimal interference to the normal operation of the electronic device. In some realizations, the device is designed to also protect users from thermal exposure.

Abstract: A receptacle assembly includes a hollow conductive cage with a front end and an opening to an interior portion of the cage. The opening is configured to receive a module assembly therein. The cage has a bottom with a bottom opening communicating with the interior portion, and the bottom is configured to be joined to a circuit board. A layered EMI shield member is provided between the bottom of the cage and the circuit board and the shield member extends completely around the bottom opening of the cage. The EMI shield member is formed as a flexible, low-cost assembly that utilizes a pair or insulative layers that flank a conductive layer.

Abstract: An electromagnetic shielding method includes the steps of disposing a flexible electromagnetic shielding film including a laminate of at least an insulating layer and a conductive metal layer to cover a portion to be electromagnetically shielded on a printed wiring board so that the insulating layer faces the printed wiring board, the conductive metal layer having a higher melting temperature than that of the insulating resin layer; and heating the electromagnetic shielding film to a temperature to melt and contract the insulating layer, thereby bonding the conductive metal layer to a grounding conductor of the printed wiring board and electrically connecting the conductive metal layer to the grounding conductor. The heating temperature is higher than the melting temperature of the insulating layer and lower than the melting temperature of the conductive metal layer.

Abstract: The present invention features a lightweight compact pump design, a cloaking pouch to block wireless signals, a rescue enclosure for a litter basket, a sliding mechanism for a tent, a shoulder strap for a sleeping bag, a holding device for a tent pole, an interchangeable fly or cover for a tent and a modular sleep system.

Abstract: An electronic device enclosure includes a first cover, a second cover located below the first cover, and a bracket for receiving a disk drive. The second cover defining a hole and comprising a shielding panel covering the hole. The shielding panel is deformable to expose the hole, for the disk drive inserting into or being removed out of the bracket.

Abstract: A carrying apparatus for carrying and shielding portable wireless transponders. A flexible, thin liner capable of blocking electromagnetic radiation is attached to the interior of a carrying apparatus such as a purse, pocket or wallet. By placing portable wireless transponder into the apparatus, the transponder is shielded from being read by an RFID base station.

Abstract: A grounding mechanism includes a grounding end, and a clip device connected to the grounding end for electrically connecting an electronic device to the grounding end. The clip device includes a first clip for contacting against a lateral side of the electronic device in a first direction so as to ground the electronic device in the first direction, and a second clip for contacting against another side of the electronic device in a second direction different from the first direction so as to ground the electronic device in the second direction.

Abstract: An apparatus includes a device contactor having an integrated radio frequency (“RF”) shield and a gasket coupled to a first surface of the device contactor. When the device contactor is removably attached to a printed circuit board (“PCB”), the gasket contacts the PCB, and the RF shield and the gasket form a Faraday cage that shields a device under test and/or circuitry associated with the device under test from RF noise.

Abstract: An inflatable, lightweight shielded enclosure that includes one or more inflatable, lightweight shielded beams arranged to support a shielded material, and an inflatable, lightweight shielded connection system for connection to a control system is provided along with related methods. The enclosure may have a weight of approximately twenty-one pounds, and provide an attenuation of 70 dB to 80 dB for a 1 GHz signal.

Abstract: An electromagnetic shielding method includes the steps of disposing a flexible electromagnetic shielding film including a laminate of at least an insulating layer and a conductive metal layer to cover a portion to be electromagnetically shielded on a printed wiring board so that the insulating layer faces the printed wiring board, the conductive metal layer having a higher melting temperature than that of the insulating resin layer; and heating the electromagnetic shielding film to a temperature to melt and contract the insulating layer, thereby bonding the conductive metal layer to a grounding conductor of the printed wiring board and electrically connecting the conductive metal layer to the grounding conductor. The heating temperature is higher than the melting temperature of the insulating layer and lower than the melting temperature of the conductive metal layer.

Abstract: Electrical components such as integrated circuits may be mounted on a printed circuit board. To prevent the electrical components from being subjected to electromagnetic interference, a radio-frequency shielding structure may be mounted over the electrical components. The radio-frequency shielding structure may be formed from a printed circuit that includes a ground plane such as a flex circuit or rigid printed circuit board that includes at least one blanket layer of metal. The printed circuit board to which the electrical components are mounted may include a recess in which the electrical components are mounted. Additional components may be mounted to the interior and exterior surface of the radio-frequency shielding structure. The radio-frequency shielding structure may be formed from a flex circuit that has slits at its corners to accommodate folding.

Abstract: A chassis structure includes a chassis member including a receiving portion and a case member including a contact surface portion mounted on the receiving portion. The contact surface portion is not fixed to the receiving portion but is movably supported by the receiving portion. A positioning portion protruding in a direction intersecting a direction extending along the surface of the contact surface portion is provided in the receiving portion, and the case member is mounted on the chassis member while an edge of the contact surface portion is in contact with the positioning portion.

Abstract: An electromagnetically shielded enclosure with operable interfaces that is portable and lightweight. The electromagnetically shielded enclosure has operable interfaces including a tactile interface through the shielding material and optionally a shielded tactile window for viewing of a secured electronic device and also for operating the secured electronic device should it have a touch screen. An internal frame is optionally provided that prevents conductive interference of a secured electronic device touch screen by the shielded tactile window. An input/output assembly is further provided to allow signals and power to be brought in or out of the enclosure to connect with the secured electronic device without compromising radio silence.

Abstract: An electrical assembly having controlled impedance signal traces and a portable electronic device comprising an electrical assembly having controlled impedance signal traces are provided. In accordance with one embodiment, there is provided an electrical assembly, comprising: a chassis for mounting electronic components, the chassis being made from a conductive material and forming a first ground plane; a first dielectric layer overlaying the chassis; a first signal trace overlaying the first dielectric layer; and a second dielectric layer overlaying the first signal trace.

Abstract: An electrical device includes a circuit board having one or more electrical components mounted to the circuit board. At least a portion of the circuit board is encapsulated in a thermoplastic polymer material to encapsulate the electrical components. The device may be fabricated by at least partially shielding the electrical components with polymer material, followed by overmolding the polymer material with thermoplastic polymer material. The shielding material may comprise a pre-formed component, or it may comprise thermoplastic polymer material that is molded around the electrical components in a first molding step or “shot”.

Abstract: A flexible thin image-sensing module with anti-EMI function includes a flexible substrate unit, an electronic element unit, an anti-EMI unit, and a conductive structure. The electronic element unit has a plurality of electronic elements disposed on a top surface of the flexible substrate unit, and the electronic elements at least include an image sensor, a low dropout regulator and a backend IC. The anti-EMI unit is disposed on a bottom surface of the flexible substrate unit. The conductive structure passes through the flexible substrate unit and is electrically connected between the electronic element unit and the anti-EMI unit in order to guide electromagnetic waves generated by the electronic element unit to the anti-EMI unit.

Abstract: A shielded cable interface module having cable receiving grooves extending laterally to an edge of the board, each including a center conductor groove, an insulator groove, and a shield groove. A center conductor via and a shield via extend through the board. A conductor plane on the cable termination side surrounds the cable receiving grooves. The conductor plane includes a non-conductor region within the conductor plane adjacent to each of the conductor center conductor grooves. Ground vias associated with the cable receiving grooves are spaced apart from and partially surround the center conductor via outside and adjacent to the non-conductor region, the ground vias extend through the printed circuit board from the cable termination side to the system interface side.

Abstract: An EMI shield having at least one compartment for enclosing circuitry of an electronic device. The shield includes a resilient layer of a thermoformable, electrically-conductive foam, the layer having first surface and a second surface defining a thickness dimension therebetween, and the layer having an interior portion surrounded by a perimeter portion. The interior portion of the layer is compressed through the thickness dimension thereof to form a top wall portion of the shield, with the thickness dimension of the perimeter portion extending downwardly from the top wall portion to form a side wall portion of the shield which together with the top wall portion defines at least a portion of the compartment.

Abstract: Contactless payment cards with on-card microchips are transported in mailers with RF shielding. The RF shielding is designed to prevent communication with and skimming of information from the contactless cards enclosed in the mailers while in transit.

Abstract: An electromagnetic shielding method includes the steps of disposing a flexible electromagnetic shielding film including a laminate of at least an insulating layer and a conductive metal layer to cover a portion to be electromagnetically shielded on a printed wiring board so that the insulating layer faces the printed wiring board, the conductive metal layer having a higher melting temperature than that of the insulating resin layer; and heating the electromagnetic shielding film to a temperature to melt and contract the insulating layer, thereby bonding the conductive metal layer to a grounding conductor of the printed wiring board and electrically connecting the conductive metal layer to the grounding conductor. The heating temperature is higher than the melting temperature of the insulating layer and lower than the melting temperature of the conductive metal layer.

Abstract: A system and method for shielding electromagnetic radiation includes an apparatus for shielding electromagnetic radiation. The apparatus includes a conductive surface comprised of electrically-conductive plastic. The apparatus further includes a flexible element comprised of electrically-conductive plastic extending from the conductive surface. The element is operable to contact an adjacent surface abutting the flexible element and form a conductive connection with the adjacent surface. When assembled with other components in a housing, the electrically-conductive surface and the flexible element may form a portion of a Faraday shield.

Abstract: An apparatus and method is provided for isolating a telecommunication device by introducing the device to a first container part of a container, the container having a first container part and a second container part, the first container part being accessed from the second container part through a first seal, the first seal having an open state and a closed state, the second container part being accessed from the environment around the container through a second seal, the second seal having an open state and a closed state. The first container part and second container part, at least in part are formed of a flexible electrical conductor to provide electromagnetic shielding. The method includes the device being introduced to the first container part of the container with the first seal and the second seal in the open state, one or both of the first and second seals then being placed in the closed state to isolate the device from external electromagnetic radiation.