Abstract: A system and method for a dual-polarized active artificial magnetic conductor (AAMC) is presented in this disclosure. An embodiment of the proposed system comprises an array of unit cells that reflects electromagnetic waves polarized parallel to a surface with a zero-degree phase shift. The array of unit cells has impedance elements connected to neighboring impedance elements with non-Foster circuits coupled in a crossover configuration, each impedance element being coupled to a ground with a conductive via.

Abstract: Antenna devices that include a frequency selective surface (FSS) resistive card (R-card) to suppress ground plane interference are provided. The antenna device can include a tightly coupled dipole array (TCDA), and the FSS R-card can be a saw-tooth ring that only attenuates the intended frequencies. The antenna device can be an extremely wideband phased array with integrated feeding network and spatial scanning down to 60°.

Abstract: An electronic device is provided The electronic device includes a housing including a first surface facing a first direction, a second surface facing a second direction opposite to the first direction, and a side member configured to enclose at least some of a space between the first surface and the second surface, a first conductive coil positioned inside the housing and configured to form a first magnetic field in a direction substantially perpendicular to the first direction or the second direction, a second conductive coil spaced apart from the first conductive coil within the housing and configured to form a second magnetic field in a direction substantially parallel to the first direction or the second direction, a communication circuit positioned inside the housing and electrically connected to the first and second conductive coils, and a processor positioned inside the housing and electrically connected to the communication circuit.

Abstract: An end-fire antenna for wideband low form factor applications includes a first metal layer, a second metal layer, and a dielectric layer disposed between the first and second metal layers. An open cavity formed in the dielectric layer that is filled with air, the cavity defined by a pair of sidewalls that extend from an aperture of the cavity to a rear wall of the cavity, where the depth of the aperture is defined between the aperture and the rear wall. The cavity is formed by selecting the width of the aperture of the cavity and the depth of the cavity such that the antenna achieves the same gain during operation irrespective of a variation in the thickness of the antenna.

Abstract: An antenna system for a global navigation satellite system reference base station is disclosed. The antenna system includes an antenna positioned above a high capacitive impedance surface (HCIS) ground plane. Over a specific range of the lateral dimension of the HCIS ground plane and the height of the antenna above the HCIS ground plane, a high level of multipath suppression and high sensitivity for low-elevated satellites can be simultaneously maintained. The HCIS ground plane can be fabricated as a flat conducting plate with an array of conducting elements such as pins, pins with expanded tips, or mushroom structures. Alternatively, the HCIS can be fabricated as a flat conducting plate with a concentric series of choke rings. The antenna system can provide a positioning accuracy of +/?1 mm, an order of magnitude improvement over previous designs.

Abstract: An antenna assembly is formed in a multilayer printed circuit board (PCB) for transceiving in a millimeter wave (mmWave) frequency band. A ground plane is formed on at least a portion of a planar surface of the multilayer PCB. Two metal components are physically attached to the multilayer PCB and electrically coupled to the ground plane. A monopole antenna is positioned vertically through one or more layers of the multilayer PCB. The antenna is positioned proximate to one lateral side of the multilayer PCB, and aligned between the two metal components. Vertical stubs are formed through the multilayer PCB, vertically aligned with the monopole antenna, and spaced to a side of the monopole antenna opposite to the one lateral side of the multilayer PCB. Each vertical stub is electrically grounded to the ground plane. The two metal components and the vertical stubs shape beam directivity of the monopole antenna.

Abstract: An image forming apparatus, including a housing, a communication interface, a light source unit, and a light guide, is provided. The communication interface includes a communication board and a looped antenna for near field communication. The communication board is arranged to be covered by the housing and has an aperture portion. The looped antenna is arranged on a circumferential edge of the aperture portion to be looped around the aperture portion. The light source includes a light source board, arranged at a position opposite to the housing across the communication interface along a direction of thickness of the communication board, and a light source mounted on the light source board. The light guide extends from the light source through the aperture portion toward the housing.

Abstract: An antenna system for a global navigation satellite system reference base station is disclosed. The antenna system includes an antenna positioned above a high capacitive impedance surface (HCIS) ground plane. Over a specific range of the lateral dimension of the HCIS ground plane and the height of the antenna above the HCIS ground plane, a high level of multipath suppression and high sensitivity for low-elevated satellites can be simultaneously maintained. The HCIS ground plane can be fabricated as a flat conducting plate with an array of conducting elements such as pins, pins with expanded tips, or mushroom structures. Alternatively, the HCIS can be fabricated as a flat conducting plate with a concentric series of choke rings. The antenna system can provide a positioning accuracy of +/?1 mm, an order of magnitude improvement over previous designs.

Abstract: To provide a semiconductor device whose reliability is improved by increase in resistance to external stress and electrostatic discharge with reduction in thickness and size achieved. An IC chip provided with an integrated circuit and a resonant capacitor portion, an antenna provided over the IC chip, and a conductive blocking body provided so as to at least partially overlap the antenna with an insulating film interposed therebetween are included. A capacitor is formed with a layered structure of the antenna, the insulating film over the antenna, and the conductive blocking body over the insulating film.

Abstract: An antenna structure includes a radiation module and a metal board. The radiation module has a first coil unit and a second coil unit. The first coil unit is coupled to the second coil unit. The first coil unit and the second coil unit have opposite direction of current. The metal board is disposed at one side of the radiation module. The metal board has an enclosed slot which has a first slot portion and a second slot portion.

Abstract: A combined RFID and wireless charging electromagnetic wave absorber, a combined RFID and wireless charging wireless antenna including same, and a method for manufacturing same. The electromagnetic wave absorber not only performs separate functions of RFID and wireless charging and provides stable operating characteristics, but also has a structure in which an electromagnetic wave absorber and a wireless antenna are integrally coupled so as to maximize the respective performance thereof. Despite a structure in which the two functions of RFID and wireless charging are combined, the thickness of the antenna can be reduced, such that it can be very useful when adopted in and applied to a mobile device, thereby contributing greatly to reducing the thickness of a smartphone.

Abstract: Antenna apparatus and methods of use and tuning. In one exemplary embodiment, the solution of the present disclosure is particularly adapted for small form-factor, metal-encased applications such as smartphones or tablets (and “phablets”) utilizing near field communication (NFC) interfaces. The solution increases the effective size of the antenna without requiring any significant additional space or other structural modifications to the host device (such as changes to the device's metal case or size), while still maintaining a high degree of electrical performance (including a high Q factor).

Abstract: In antenna device, a coil conductor of an antenna coil module and a conductor layer at least partially overlap. A current flows in the conductor layer to block a magnetic field generated by a current flowing in the coil conductor. A current, which flows around the periphery of an opening of the conductor layer, flows along the periphery of a slit and around the periphery of the conductor layer due to a cut-edge effect. Since magnetic flux does not pass through the conductor layer, magnetic flux attempts to bypass the conductor layer along a path in which the conductor opening of the conductor layer is on the inside and the outer edge of the conductor layer is on the outside. As a result, the magnetic flux generates relatively large loops that link the inside and the outside of a coil conductor of an antenna on a reader/writer side.

Abstract: An electronic device is provided. The electronic device includes a printed circuit board (PCB), a shield can disposed on the PCB, an antenna radiator of which at least a part enters an internal space of the shield can and is installed at an inner surface of the shield can, and an electrical connecting means which is installed at a corresponding position of the PCB so as to be electrically connected with the at least a part of the antenna radiator installed at the inner surface of the shield can.

Abstract: A coupling area enhancement device includes a small coil and a large coil on opposing sides of a sheet of electromagnetic interference (EMI) absorptive material. The coupling area enhancement device may include one or more holes and may include adhesive material and sticker covers. Placement of the coupling area enhancement device may be accomplished by sticking the small coil to a host device near a contactless antenna. The large coil may also be stuck to a battery cover.

Abstract: An antenna and a communication device thereof are provided. The antenna includes at least one ground and at least one radiating portion. The ground is disposed on a dielectric substrate, and the radiating portion includes at least one signal source and at least one closed conductor loop. The closed conductor loop has a first coupling conductor portion and a second coupling conductor portion, and the closed conductor loop has a plurality of bending portions to form a three-dimensional structure, and a first coupling gap is formed between the first and the second coupling conductor portions. The closed conductor loop further has a feeding portion and a short-circuit portion to form a second coupling gap between them. The feeding portion is electrically connected or coupled to the at least one signal source, and the short-circuit portion is electrically connected or coupled to the ground.

Abstract: The Wireless Integrated Network Sensor Next Generation (WINS NG) nodes provide distributed network and Internet access to sensors, controls, and processors that are deeply embedded in equipment, facilities, and the environment. The WINS NG network is a new monitoring and control capability for applications in transportation, manufacturing, health care, environmental monitoring, and safety and security. The WINS NG nodes combine microsensor technology, low power distributed signal processing, low power computation, and low power, low cost wireless and/or wired networking capability in a compact system. The WINS NG networks provide sensing, local control, remote reconfigurability, and embedded intelligent systems in structures, materials, and environments.

Abstract: A multi-field antenna able to receive a signal over one field selected from a plurality of different fields of the antenna includes an interface to connect the antenna to a signal processing device, such as an RFID reader, to receive and process the signal. The antenna includes a first magnetic loop configured to be tuned by a first tuner to provide a first volume field for reading data; a second magnetic loop configured to be tuned by a second tuner to provide a second volume field for reading data, the second volume field being smaller than the first volume field; and a switch to configure the first tuner and the second tuner to select the one field from the plurality of fields. The multi-field antenna can have a wide volume field selected to detect items within a large area and then the multi-field antenna can be switched to select a smaller volume field to detect items within a substantially smaller area.

Abstract: Described herein are techniques related to near field coupling and wireless power transfers. In an implementation, a portable device may include full metallic chassis devices. The full metallic chassis devices may include a keyboard and/or trackpad that include a plastic keycap. The plastic keycap may integrate a booster component to increase near field communications (NFC) range of a coil antenna that is integrated onto a surface plane above a circuit board of a switch that is connected to the plastic keycap. In an implementation, a ferrite material is inserted between the coil antenna and the circuit board to protect the coil antenna from Eddy currents that may be induced on a metallic chassis that lie underneath the circuit board.

Abstract: A diagnostic system for monitoring changes in a medium is disclosed. The system includes a transmitter configured to generate and transmit a time-varying magnetic field into a medium responsive to a first signal. The system also includes a receiver positioned on an opposite side of the medium from the transmitter and configured to generate a second signal responsive to a received magnetic field at the receiver. The system also includes a processing unit configured to determine a phase shift between the transmitted magnetic field and the received magnetic field for a plurality of frequencies of the transmitted time-varying magnetic field.

Abstract: A gaming table with an upper surface that includes a gaming chip placement area and a lower surface opposite the upper surface is provided. The gaming table also includes a housing coupled to one of the upper surface and the lower surface of the gaming table, an antenna coupled to the housing, wherein the antenna is configured to form an electromagnetic field that defines a zone of communication in which a gaming chip including a radio frequency identification (RFID) tag can be read.

Abstract: A communication antenna for a thin-film mobile device particularly relates to an antenna arranged on a cover of the mobile device and having an enhanced effect on transmission or reception of signals. The communication antenna connected to a transceiver circuit of the mobile device includes a plastic substrate, a metal layer joining an interface layer coated on the plastic substrate, wherein the metal layer is engraved with a separating loop that may have various shapes and areas such that the separating loop encloses an antenna that may have various shapes and areas, and an insulating protective layer coated on the engraved metal layer so as to cover the metal layer and the separating loop. Thereby, the mobile device has an enhanced effect on transmission or reception of signals and provides prevention of electromagnetic interference (EMI).

Abstract: Apparatus and methods for providing a substantially surface independent tagging system are disclosed. A resonant dielectric cavity is defined between upper and lower conducting layers, and closed at one end by a conducting base portion. Incident radiation couples into the cavity and is resonantly enhanced. An electronic device or tag paced at the edge of the cavity experiences a high electric field strength on account of this enhancement and is driven into operation.

Abstract: The wireless tag includes an antenna conductor; a first power-supply conductor which is electromagnetic-inductively coupled with the antenna conductor; and a second power-supply conductor which is loop-shaped and which is electrically coupled with the first power-supply conductor.

Abstract: An antenna is provided. The antenna includes a radiator, a feed conductor and a ground conductor. The radiator includes a body and a parasitic element. An aperture is formed on the body, and the body encloses the aperture. The parasitic element is connected to the body and extended into the aperture, wherein the parasitic element is connected to the body at a parasitic location. The feed conductor is connected to the body, wherein a signal, fed to the body by the feed conductor, travels on the body, and passes the parasitic location to the parasitic element. The ground conductor is connected to the body.

Abstract: A device capable of enhancing an electric field to drive an electromagnetic tag into operation is switchable between states to control operation of the tag. Enhancement is provided by a dielectric cavity structure defined between first and second conducting layers. Different states of the device may have different resonant frequencies and read ranges according to the characteristics of the enhancement. As such a container can be provided which includes a tag which switches states on opening, allowing improved tracking characteristics.

Abstract: There is provided a bidirectional transmission coil capable of miniaturizing a structure and carrying out reliable transmission of a data signal. A transmitting coil L1 generates a magnetic flux of a transmission signal by a high frequency signal applied thereto. A receiving coil L2 is arranged to be positioned concentrically with the transmitting coil L1, for inducing a reception signal by the magnetic flux from outside. A first cancel coil Lac is connected to the transmitting coil L1 in series so as to be led-out from a middle of the transmitting coil L and is led-in to the lead-out part. The first cancel coil Lac is arranged so as to sandwich the receiving coil L2 between the first cancel coil Lac and the transmitting coil L1, wherein the magnetic flux in a direction opposite to the magnetic flux from the transmitting coil L1 is generated in the receiving coil L2.

Abstract: Electronic devices may be provided with antenna structures and antenna isolation element structures. An antenna array may be located within an electronic device. The antenna array may have multiple antennas and interposed antenna isolation element structures for isolating the antennas from each other. An antenna isolation element structure may have a dielectric carrier with a longitudinal axis. A sheet of conductive material may extend around the longitudinal axis to form a conductive loop structure. The loop structure in the antenna isolation element may have a gap that spans the sheet of conductive material parallel to the longitudinal axis. Electronic components may bridge the gap. Control circuitry may adjust the electronic components to tune the antenna isolation element.

Abstract: A system for reading RFID tags of articles within a cabinet includes a repositionable shelf. The repositionable shelf includes an antenna assembly having three antenna pairs. Each antenna pair has a loop antenna and a figure eight antenna. The antenna pairs are on a PC board. The PC board includes an RJ45 connector which provides both power to the antenna assembly as well as a communication interface for the antenna assembly. The RJ45 connector could be used to provide the RF signals from the antenna to a reader. The system could also include a repositionable divider for placement perpendicular to the repositionable shelf. The repositionable divider also includes a loop antenna and a figure eight antenna.

Abstract: Apparatus and methods for providing a substantially surface independent tagging system are disclosed. A resonant dielectric cavity is defined between upper and lower conducting layers, and closed at one end by a conducting base portion. Incident radiation couples into the cavity and is resonantly enhanced. An electronic device or tag paced at the edge of the cavity experiences a high electric field strength on account of this enhancement and is driven into operation.

Abstract: A multiple-input multiple-output (MIMO) device includes a substrate, a shielding cover and a MIMO antenna. The shielding cover is positioned on the substrate, and includes a plurality of sidewalls. The MIMO antenna includes a first solid antenna, a second solid antenna, and a plane antenna. The first solid antenna and the second solid antenna are electrically connected to two ends of one sidewall of the shielding cover, respectively. The first plane antenna is configured on the substrate, and disposed between the first solid antenna and the second solid antenna.

Abstract: Systems, tags and methods for disabling transponders used in electronic toll collection or other RFID systems, wherein the transponders include an antenna and RFID circuitry. The transponders can be selectively disabled by positioning (e.g., pivotably moving) a disabling member having a metallic portion to an operative position over the antenna of the RFID system, whereupon the metallic portion is coupled to the antenna in such a manner as to disable the RFID circuitry so long as the disabling member is at the operative position. The RFID circuitry is arranged to be automatically enabled upon removal of the disabling member from the operative position (e.g., pivoting the disabling member back to an inoperative position).

Abstract: A Multiple Input Multiple Output (MIMO) antenna apparatus is provided. The apparatus includes antenna devices that operate in respective resonant frequency bands. The apparatus also includes a main board comprising a device region and a ground region. The antenna devices are disposed on the device region. The ground plate is disposed on the ground region for grounding the antenna devices. The apparatus also includes at least one isolation device having a negatively charged line that protrudes from the ground plate and extends between the antenna devices on the device region, and a positively charged line that extends around the negatively charged line and connects the antenna devices to each other. The isolation device induces an electromagnetic wave that is generated by the antenna devices between the negative and positively charged lines to isolate the antenna devices from each other.

Abstract: A crossed dual tag includes two tags each of which comprises, on one plane, a dipole antenna formed with conductors, a feeding part to which an IC chip is connected at the center of the dipole antenna, and a loop-shaped inductance part that is formed between the dipoles of the dipole antenna and connected to the dipoles of the dipole antenna in parallel with respect to the feeding part. The two tags are crossed at right angles, and stacked to contact as closely as possible so that the loops of the inductance parts overlap as wide as possible. A reader/writer of an RFID system sequentially switches the surface of a circular polarized wave of a wireless signal between forward and backward directions, and reads information written to a user memory area from the tag that responds more strongly.

Abstract: Systems and methods for disabling transponders used in electronic toll collection or other RFID systems, wherein the transponders include an antenna and RFID circuitry. The transponders can be selectively disabled by releasably securing a disabling device having a metallic portion at an operative position over the antenna of the RFID system, whereupon the metallic portion is coupled to the antenna in such a manner as to disable the RFID circuitry so long as the disabling device is at the operative position. The RFID circuitry is arranged to be automatically enabled upon removal of the disabling device from the operative position.

Abstract: A system is disclosed for minimizing coupling nulls between an electromagnetic field derived from one or more sources and a plurality of randomly oriented RFID tags, wherein the electromagnetic field is rotated relative to the tags such that no tag is persistently located in a coupling null relative to the field. The source of the electromagnetic field may include a passive antenna or loop that changes its orientation relative to a direction of movement of the tags. The source of the electromagnetic field may further include an active antenna or loop that is electromagnetically coupled to the passive antenna or loop. A method for minimizing coupling nulls between the electromagnetic field and the randomly oriented tags is also disclosed.

Abstract: An antenna unit includes a loop antenna 1; a metallic element 6 provided on one side of an aperture area of the loop antenna 1; and a coil 2 inserted into a line of the loop antenna 1. A coil axis of the coil 2 is parallel to the aperture area of the loop antenna 1 and not parallel to a direction of an electric current flowing through portions of the line of the loop antenna 1 before and after a point where the coil 2 is inserted.

Abstract: Apparatus and methods for providing a substantially surface independent tagging system are disclosed. A resonant dielectric cavity is defined between upper and lower conducting layers, and closed at one end by a conducting base portion. Incident radiation couples into the cavity and is resonantly enhanced. An electronic device or tag paced at the edge of the cavity experiences a high electric field strength on account of this enhancement and is driven into operation.

Abstract: According to an aspect of the present invention, there is provided a radio system including: a first radio apparatus that has a first loop antenna; and a second radio apparatus that has a second loop antenna and that performs a radio communication with the first radio apparatus when the second loop antenna is opposed with the first loop antenna, wherein the second radio apparatus has a shield member that is formed of a magnetic substance and disposed to shield at least a portion of the second loop antenna with respect to the first loop antenna when the radio communication is performed.

Abstract: A medical device and system is provided with a device housing and with a radio frequency detection device. The radio frequency detection device is functionally connected to an antenna for detecting a radio frequency identification element. The radio frequency detection device has a transmitter and an at least partly electrically conductive shield, which encloses at least the transmitter such that a field generated by the transmitter is effectively shielded towards the outside and the antenna is arranged within the housing and outside the shield.

Abstract: Without using a component such as a chip coil, a winding pattern is formed with a wire with which a main wiring pattern is formed. This enables to deal with the flexibility by realizing a thin product using a coil antenna. Further, the wiring pattern is designed such that the winding pattern is provided and distributed to the main wiring pattern forming a loop, and is formed with the wire so as to have a wound shape small enough compared with the main wiring pattern. In this way, the ratio of the self-inductance to the mutual inductance is appropriately made further large, so that the mutual inductance is made comparatively small.

Abstract: To provide a cell phone equipped with a broadcast receiver that delivers a high receiving sensitivity and antenna performance in various usage states. A loop element 12 as an antenna for receiving television broadcast is arranged in a range (c) of an upper end portion of an upper housing 1. An end part of an upper circuit board 6 is matched with a portion shown by (a) so that a conductor other than the antenna element does not exist in the range (c). A monopole element 19 for cell phone communication is arranged at a lower end portion of a lower housing 2.

Abstract: Systems and methods for disabling transponders used in electronic toll collection or other RFID systems, wherein the transponders include an antenna and RFID circuitry. The transponders can be selectively disabled by releasably securing a disabling device having a metallic portion at an operative position over the antenna of the RFID system, whereupon the metallic portion is coupled to the antenna in such a manner as to disable the RFID circuitry so long as the disabling device is at the operative position. The RFID circuitry is arranged to be automatically enabled upon removal of the disabling device from the operative position.

Abstract: The invention provides protection to wireless portable transponders from unauthorized interrogation by employing a mechanical means for disabling reception by or from the antenna of the transponder. Transponders include RFID tags that are attached to items that a persons may purchase or carry. Such transponders generally have means for receiving and storing electronic and other information, commonly in binary form using memories as in electronic circuits, etc. The invention is designed to provide privacy of electronic information. The tags can be protected from receiving or providing unauthorized or unwanted information. The invention provides the mechanical means that permit the owner to decide when reception/interrogation of personal or other information is not desired by employing the provided mechanical disable control means.

Abstract: Embodiments of the invention provide a method, system and apparatus for detecting a merchandise marker in which a first antenna has a circuit having a first loop defining a first area and a second loop defining a second area substantially coplanar with the first area. A second antenna is substantially coplanar and orthogonally positioned with respect to the first antenna. The second antenna has a circuit having a third loop defining a third area and a fourth loop defining a fourth area substantially coplanar with the third area.

Abstract: A communication device able to share one antenna and in addition able to sufficiently exhibit characteristics of a function as a reader, writer and a card function, a non-contact type IC card provided with that, and an information apparatus, wherein the device has a first transmission circuit 220 having first and second output terminals and outputting a carrier from the first and second output terminals in a first mode; an antenna circuit 210 including a node ND210, an inductor 211 having one end connected to the node, and having the other end connected to the second output terminal of the first transmission circuit, and a capacitor 212 connected between the node and the first output terminal of the first transmission circuit; a second transmission circuit 230 connected to the node of the antenna circuit and outputting the transmission data in a second mode; at least one reception circuit 240 connected to the node of the antenna circuit and performing reception processing with respect to data received at the

Abstract: Devices and methods are provided to enhance magnetic field communication. One aspect of the present subject matter relates to a method for transmitting and receiving signals using an antenna element electrically connected to a driver and an amplifier. According to various embodiments of the method, a first signal is transmitted from the antenna element and a second signal that was induced in the antenna element is received. Transmitting the first signal includes driving the first signal through the antenna element using the driver, and monitoring the first signal through an input impedance of the amplifier. Receiving the second signal includes reducing the input impedance of the amplifier, and receiving the second signal at the amplifier through the reduced input impedance. Various embodiments shield the antenna element from electric and electromagnetic fields. Other aspects are provided herein.

Abstract: The invention relates to a multiple phase shifter for protecting individuals against electromagnetic waves. The invention comprises several phase shift modules which each comprise two identical or homothetic flat loops which are electrically connected by means of two inter-loop connection elements at a first opening in each of the loops and which are electrically insulated from one another with the exception of the inter-loop connection elements. Each module is electrically connected to another module by means of two inter-module connection elements and is essentially identical or homothetic to the other modules. The inter-module connection elements connect one of the loops of one module at a second opening in the loop to one of the loops of another module at a second opening in said loop. The modules are electrically insulated from one another with the exception of the inter-module connection elements.

Abstract: A seat for a vehicle includes: a detecting sensor detecting an occupant having a planar antenna electrode, at which electric filed is generated, and a ground electrode arranged with a clearance along an outer periphery of the antenna electrode. The antenna electrode can be provided with a hole at the center of the antenna electrode.

Abstract: A broadband antenna is capable of generating an upper resonant mode (at about 700 MHz) from a first radiating arm and a lower resonant mode (at about 500 MHz) from a second radiating arm. The first and second radiating arms are bent at least one time. An open end of the second radiating arm is extended toward an open end of the first radiating arm with a predefined distance there between. The predefined distance can be adjusted to improve the impedance matching of lower resonant mode, which can be further combined with the upper resonant mode to achieve a broad bandwidth covering the complete spectrum of digital TV channels (470-862 MHz).