2373 results about "Low frequency band" patented technology

An LC parallel resonance circuit is connected in series with the power supply side of the antenna conductor portion. The antenna conductor portion is configured so as to resonate at a frequency slightly lower than the center frequency in the higher frequency band of two frequency bands for transmitting and receiving radio waves. The LC parallel resonance circuit is configured so as to resonate substantially at the center frequency in the lower frequency band for transmitting and receiving a radio wave and be capable of providing to the antenna conductor portion a capacitance for causing the antenna conductor portion to resonate at the center frequency in the higher frequency band. Thus, a circuit for changing the upper and lower frequency bands is not needed. Such a change-over circuit, which is complicated, causes problems in that the conduction loss increases, and the antenna sensitivity deteriorates. Without need of the change-over circuit, the conduction loss can be reduced, the antenna sensitivity can be enhanced and costs can be reduced.

A multi-band antenna (1) used in an electronic device and formed of a metallic sheet by defining holes therein, including a first radiating portion (30), a second radiating portion (31), a third radiating portion (32), a ground portion (2), and a coaxial transmission line (4). The first radiating portion, the ground portion and the coaxial transmission line cooperatively form a loop antenna operated at a higher frequency band of about 5.15-5.875 GHz. The second radiating portion, the ground portion and the coaxial transmission line cooperatively form a first inverted-F antenna operated at another higher frequency band of about 5.725-5.875 GHz. The third radiating portion, the ground portion and the coaxial transmission line cooperatively form a second inverted-F antenna operated at a lower frequency band of about 2.4-2.5 GHz.

Image data is compressed by decomposing the image data into a plurality of resolutions or sized by wavelet decomposition, followed by compression of the resulting data sets. Adaptive Huffman code compression is optimized for compressing the data sets, predictive errors for a low frequency band and the wavelet transformed values for high frequency bands. The image data is thus compressed losslessly and in multiple resolutions such that desired resolution images can be reconstructed and transmitted in accordance with available-bandwidth and viewing capabilities.

A chassis-excited antenna apparatus, and methods of tuning and utilizing the same. In one embodiment, a distributed loop antenna configuration is used within a handheld mobile device (e.g., cellular telephone). The antenna comprises two radiating elements: one configured to operate in a high-frequency band, and the other in a low-frequency band. The two antenna elements are disposed on different side surfaces of the metal chassis of the portable device; e.g., on the opposing sides of the device enclosure. Each antenna component comprises a radiator and an insulating cover. The radiator is coupled to a device feed via a feed conductor and a ground point. A portion of the feed conductor is disposed with the radiator to facilitate forming of the coupled loop resonator structure.

An apparatus for encoding an audio signal to obtain an encoded audio signal to be used by a decoder having a high frequency reconstruction module for performing a high frequency reconstruction for a frequency range above a crossover frequency includes, a core encoder for encoding a lower frequency band of the audio signal up to the crossover frequency, the crossover frequency being variable, and the core encoder being operable on a block-wise frame by frame basis, and a crossover frequency control module for estimating, dependent on a measure of the degree of difficulty for encoding the audio signal by the core encoder and / or a boarder between a tonal and a noise-like frequency range of the audio signal, the crossover frequency to be selected by the core encoder for a frame of a series of subsequent frames, so that the crossover frequency is variable adaptively over time for the series of subsequent frames.

A method and apparatus for detecting microphone interference includes first and second built-in microphones producing first and second microphone signals. A first filter bank creates first high-frequency-band and first low-frequency-band signals from the first microphone signal. A second filter bank creates second high-frequency-band and second low-frequency-band signals from the second microphone signal. A first measurement calculator determines a high-frequency-band energy value from the first high-frequency-band signal and the second high-frequency-band signal when the first and second high-frequency-band signals' magnitudes exceeds predetermined thresholds. A second measurement calculator calculates a low-frequency-band energy value from the first low-frequency-band signal and the second low-frequency-band signal when the first and second low-frequency-band signals' magnitudes exceed predetermined thresholds. A logic control block, coupled to the first measurement calculator and the second measurement calculator, detects microphone interference and produces an output signal indicating microphone occlusion or wind noise.

The present application relates in one aspect to a method of controlling diaphragm excursion of an electrodynamic loudspeaker. The method comprises dividing the audio input signal into at least a low-frequency band signal and a high-frequency band signal by a band-splitting network and applying the low-frequency band signal to a diaphragm excursion estimator. The instantaneous diaphragm excursion is determined based on the low-frequency band signal. The determined instantaneous diaphragm excursion is compared with an excursion limit criterion. The low-frequency band signal is limited based on a result of the comparison between the instantaneous diaphragm excursion and the excursion limit criterion to produce a limited low-frequency band signal which is combined with the high-frequency band signal to produce an excursion limited audio signal.

A multi-band microwave antenna which is resonant and radiant at a high frequency band and at one or more lower frequency bands includes an electrically-conductive ground plane on one face of a dielectric substrate; an electrically conductive strip line on the opposite face of the dielectric substrate; a curved slot formed in the ground plane having a feed side electromagnetically coupled to the feed end of the strip line, and a load side electromagnetically coupled to the load end of the strip line, such that the slot is resonant and radiant at the high frequency band; and a further electrical conductor electrically connected to the ground plane to serve as a continuation thereof at the load side of the slot and electromagnetically coupled to the slot at the lower frequency bands such as to cause the slot to be resonant and radiant also at the lower frequency band or bands.

The present invention relates to a dual-band omnidirectional antenna for wireless LANs. The antenna has a planar dielectric substrate, and first and second conductive patterns. The planar dielectric substrate has two parallel surfaces. The first conductive pattern is arranged on one surface of the substrate, and is provided with a first feeder line arranged on a longitudinal central line of the substrate and a plurality of radiating elements connected to the first feeder line and designed such that some of them operate in a high frequency band (4.9 to 5.85 GHz frequency band), and others thereof operate in a low frequency band (2.4 to 2.5 GHz frequency band). The second conductive pattern is arranged on the other surface of the substrate, and provided with a second feeder line arranged on a longitudinal central line of the substrate and a plurality of radiating elements connected to the second feeder line arid up-down symmetrically arranged with respect to the radiating elements on the first conductive pattern.

A point-to-multipoint wireless access system includes a wireless base station and a plurality of wireless subscriber's terminals, wherein the down-link channels from the base station to the respective subscriber's terminals use a higher frequency band, and the up-link channels from the respective subscriber's terminals to the base station use a lower frequency band which is exempt of license.

A dual frequency band inverted-F antenna used for communicating a low frequency signal and a high frequency signal includes a substrate, a ground metal, a vortical metal structure, a short circuit leg, a feeding leg, and a terminal micro strip. The ground metal and the terminal micro strip are formed on the lower surface of the substrate. The vortical metal structure, formed on the upper surface of the substrate, further has a short circuit end and an open circuit end. The short circuit leg connects electrically the short circuit end of the vortical metal structure with the ground metal. The feeding leg extends along a predetermined direction of the vortical metal structure to couple with a feeding circuit on the substrate. The terminal micro strip connects electrically to the open circuit end through a first conductive aperture. By increasing the encircling number of the vortical metal structure, the coupling effect is generated so that the equivalent wavelength of the high frequency signal can be longer, thus the resonance frequency thereof can be reduced, and so a first frequency can be still kept communicating at a lower frequency band and a second frequency can also be added for communicating at a higher frequency band.

A method and system for a long range Radio Frequency (RF)-based identification, tracking and locating of objects. The method and system use a narrow bandwidth ranging signal(s), including VHF of lower frequency bands, which minimizes propagation loss and loss of accuracy of the RF locating signals. The method and system includes narrow bandwidth ranging signal multi-path mitigations processor, which further improves the track-locate accuracy. The signal is sent from a Master Unit(s) to a Tag. The signal traveling time is recorded and the distance between the Master(s) and the Tag is calculated. The method and system allow achieving a longer distance of the RF narrow bandwidth ranging signal penetration and an increased accuracy by using VHF bands in conjunction with the narrow bandwidth ranging signal multi-path mitigations processor. The techniques of Digital Signal Processing and Software-Defined Radio are used. The actual waveforms transmitted and received by the radios are defined by the software. The roles of the Master Unit(s) and the Tag can be reversed.

The invention discloses an antenna device for a full metal shell. The antenna device comprises a metal shell arranged at the back of communication equipment, antenna branches and feeding points, wherein a metal frame extending from the back of the communication equipment to the side face is arranged around the periphery of the metal shell; the metal shell is segmented and separated into a first metal shell, a second metal shell and a third metal shell; the feeding points are respectively positioned between the first metal shell and the second metal shell and between the second metal shell and the third metal shell; an antenna branch I arranged at the first metal shell and an antenna II arranged at the third metal shell are respectively connected with a radio-frequency signal source of a PCB (Printed Circuit Board) mainboard arranged on the second metal shell, and signals are correspondingly fed in the first metal shell and the third metal shell through the feeding points. With a three-section type full metal shell structure, the metal frame becomes a part of the antenna, the first metal shell and the third metal shell can be used as antennas at the same time, and the antenna device has the advantages of ultra-wide low-frequency band width and high-frequency band width.

A dual-antenna diversity antenna system that operates within a low frequency band range is disclosed. Two antennas are folded separately onto a single three dimensional dielectric substrate in a meander pattern configuration. Each antenna has an independent feed port and ground pin. The two antennas are configured within a compact mobile terminal to produce high isolation and low correlation at resonating frequencies within the 700 Megahertz frequency band.

Systems and Methods are provided for relaying wireless signals bi-directionally between user equipment (UE) and base station transceivers (BTS). Various slot types are defined during which a relay node takes on the personality of either the UE or the BTS. In order to implement the relay node with a single transceiver chain, a first switching matrix is used to switch high band and low band RF bandpass filters between receive and transmit paths, and a second switching matrix is used to switch two frequency sources between the receive and transmit path. In this way, a single receive path can function both in the UE and BTS personality, as can the single transmit path.

A mobile communication system comprises a detecting unit to detect information concerning a moving speed of a mobile terminal, and a selection controlling unit to select a use frequency in a higher frequency band when the speed information detected by the detecting unit is a higher speed, while selecting the use frequency in a lower frequency band when the detected information is a lower speed, and assigning it to the mobile terminal. In a mobile communication system in which a relationship between a terminal moving speed (Doppler frequency) and transmission quality degradation is non-monotonous, the communication quality can be improved and the channel capacity can be increased.

A method of wave propagation from 100–10000 GHz. The currently disclosed method and apparatus adapts micro-opto-electro-mechanical systems (MOEMS) technologies and processes to construct Kinoform optical components from microwave to terahertz range. The method uses induced coupled plasma (ICP) and gray scale processes for upper terahertz band; LIGA-based high aspect ratio (HAR) and gray scale processes are for the mid band; and computer numerical control (CNC) for lower band. In all cases, the thickness of any processed components is about the respective wavelength and system efficiency is about 95%. A Kinoform lens element is designed at 5000 GHz. However, the method is applicable for the entire terahertz band.

The present invention discloses an antenna for ultra-wideband (UWB) communication having a band-stop characteristic. According to an embodiment of the present invention, the UWB antenna is a patch antenna employing microstrip feeding. In order to expand a bandwidth at a low frequency band, a stub is formed in a radiating element. Furthermore, since steps are formed in a ground plane, an antenna characteristic at an intermediate frequency band can be improved and a UWB characteristic can be obtained. According to another embodiment of the present invention, the UWB antenna is a patch antenna employing microstrip feeding and has a recess formed in the ground plane, thereby implementing the UWB characteristic. The antenna of the present invention has an inverse U-shaped slot formed in the radiating element, thus implementing the band-stop characteristic at the UNII band. In addition, the antenna of the present invention has includes a ground plane having a small area and has omnidirectional radiating patterns accordingly.

PCT No. PCT / IL96 / 00037 Sec. 371 Date Jun. 11, 1999 Sec. 102(e) Date Jun. 11, 1999 PCT Filed Jul. 4, 1996 PCT Pub. No. WO98 / 01921 PCT Pub. Date Jan. 15, 1998A dual-frequency array antenna having an essentially planar structure with electronic beam steering capability in both a low and high frequency band independently of each other, constructed, in a layered formation, from a top planar array antenna unit operating in the low frequency band and a bottom planar array antenna unit operating in the high frequency band. The top planar array antenna is transparent to frequencies in the high frequency band.

A distributed multiband antenna intended for radio devices, and methods for designing manufacturing the same. In one embodiment, a planar inverted-F antenna (PIFA) configured to operate in a high-frequency band, and a matched monopole configured to operate in a low-frequency band, are used within a handheld mobile device (e.g., cellular telephone). The two antennas are placed on substantially opposing regions of the portable device. The use of a separate low-frequency antenna element facilitates frequency-specific antenna matching, and therefore improves the overall performance of the multiband antenna. The use of high-band PIFA reduces antenna volume, and enables a smaller device housing structure while also reducing signal losses in the high frequency band. These attributes also advantageously facilitate compliance with specific absorption rate (SAR) tests; e.g., in the immediate proximity of hand and head “phantoms” as mandated under CTIA regulations. Matching of the low-frequency band monopole antenna is further described.

An encoding device (100) includes (i) a first encoding unit (132) that encodes spectral data in the lower frequency band represented by a plularity of parameters, out of the spectral data obtained by transforming an audio signal inputted for a fixed time length, (ii) a second quantizing unit (133) that generates sub information representing characteristics of the spectral data in the higher frequency by fewer parameters than those for the lower frequency band, out of the spectral data obtained by the transformation, (iii) a second encoding unit (134) that encodes the generated sub information, and (iv) a stream output unit (140) that outputs the data encoded by the first encoding unit (132) and the data encoded by the second encoding unit (134).

Integrated telephone with an xDSL-modem (2), comprising a splitter unit (6) for separating telephone signals received via a telephone line (9) in a low-frequency band from data signals received in a high-frequency band via the telephone line (9), a telephone set (3) connected to the splitter unit (6) for the transmission of telephone signals in the low-frequency band; and a high-speed xDSL-modem (2) connected to the splitter unit (6) for the transmission of data signals in the high-frequency band.

A frame structure for support of large delay spread deployment scenarios (e.g., cellular system operation in large cell sizes or low frequency bands) is generally presented. In this regard a method is introduced comprising partitioning a radio frame into a plurality of equal-sized (or non-equal-sized) sub-frames to simplify system implementation. Other embodiments are also disclosed and claimed.

A diversity antenna system that operates within a low frequency band ranging from 700 Megahertz is disclosed. A plurality of antennas are folded onto a single printed circuit in a meander pattern configuration. Each antenna has an independent feed port and ground pin. The plurality of antennas are configured within a compact mobile phone space to produce a high isolation and low correlation at resonating frequencies within the 700 Megahertz frequency band.

A chassis-excited antenna apparatus, and methods of tuning and utilizing the same. In one embodiment, a distributed loop antenna configuration is used within a handheld mobile device (e.g., cellular telephone). The antenna comprises two radiating elements: one configured to operate in a high-frequency band, and the other in a low-frequency band. The two antenna elements are disposed on different side surfaces of the metal chassis of the portable device; e.g., on the opposing sides of the device enclosure. Each antenna component comprises a radiator and an insulating cover. The radiator is coupled to a device feed via a feed conductor and a ground point. A portion of the feed conductor is disposed with the radiator to facilitate forming of the coupled loop resonator structure.

A mobile communications device has a multifrequency band antenna with a low band portion (LB) tuned to a low frequency band, and a first high band portion (HB1) tuned to a first high frequency band at higher frequencies than the low frequency band. The low band portion (LB) and the first high band portion (HB1) have a common first grounding point (GP1), a common feeding point (FP) for feeding input signals to the antenna and for receiving signals from the antenna, and a first conductor portion (CP1), which forms part of the low band portion (LB) and of the first high band portion (HB1). The first conductor portion (CP1) is electrically connected to the first grounding point (GP1) and to the common feeding point (FP). A second high band portion (HB2) is coupled to the first conductor portion (CP1) and tuned to a second high frequency band at a higher frequency than the low frequency band and different from the first high frequency band. A switching network is connected between the second high band portion and ground, allowing the resonant frequency of the second high band portion to be varied, on the basis of a signal which depends on the operating mode of the device, thereby allowing four band operation.