4611 results about "Insertion loss" patented technology

Disclosed are various embodiments of circuitry for coupling first and second transceivers of a dual band radio telephone to integral and external antennas. The circuitry uses impedance matching lengths of transmission lines and switches arranged to provide a minimum insertion loss. Also disclosed is an embodiment for use with a single band radio telephone, such as a digital TDMA radio telephone that either transmits or receives at any given time. Also disclosed is an antenna switching arrangement for a dual band phone that eliminates a requirement for duplexers.

A component that functions with bulk acoustic waves, particularly a bandpass filter, has an increased number of degrees of design freedom in order to improve the transmission characteristics of the component. The component has BAW resonators coupled acoustically in the vertical and/or lateral direction through common electrodes, coupling layer systems and through the excitation of lateral acoustic modes. Through the acoustic coupling of the resonators, it is possible to create additional pole points in the transfer function so that in this manner, the rejection band characteristics of a bandpass filter can be improved. Through acoustic paths which are added in addition to the electrical connection, the insertion loss can be reduced. Through an acoustic coupling instead of an electrical connection, decoupling between input and output loops of a circuit can be achieved.

Techniques for improving electrical performance of a connector. The techniques are compatible with the form factor of a standardized connector, such as an SFP connector or stacked SFP. The resulting connector has reduced insertion loss for high speed signals. Such techniques, which can be used separately or together, include shaping of conductive elements within the connector while still retaining the same mating contact arrangement. Changes may be made at the contact tail portions or in the intermediate portions where engagement to a connector housing occurs. The techniques also include the incorporation of lossy bridging members between conductive elements designated to be ground conductors. For connectors according to the stacked SFP configuration, multiple bridging members may be incorporated at multiple locations within the connector.

The present invention provides for dynamic insertion loss control for a 10/100/1000 megahertz Ethernet power on differential cable pairs. A power feed circuit supplies power to a network attached device (PD). An insertion loss control circuit limits power loss in a coupled power feed circuit. The insertion loss control circuit determines an insertion loss limit and senses an average power of the power signals to produce a common mode feedback signal to the power feed circuit. The insertion loss limit is determined for the received signals based on a differential RMS of the received Ethernet power signals as seen by a differential transistor pair. Alternatively, the insertion loss limit may be determined logically by the higher layers of the network protocol based on the AC differential portion of the network power signal. When the insertion loss limit is determined based on the differential RMS, the insertion loss control circuit is operable to automatically reduce the insertion loss based upon transmission losses experienced over the network connection between the power sending equipment and network-attached device.

The invention discloses a rectangular waveguide directional coupler. The rectangular waveguide directional coupler comprises a main rectangular waveguide serving as a main microwave channel, a sub-rectangular waveguide serving as a sampling signal channel, and coupling holes serving as coupling channels, wherein the main mode H-surface of the main rectangular waveguide is parallel to that of the sub-rectangular waveguide; the main rectangular waveguide is isolated from the sub-rectangular waveguide; the main rectangular waveguide is communicated with the sub-rectangular waveguide through one or two coupling holes; at least one coupling hole includes a hollow coupling pipe attached with the sidewall of the main rectangular waveguide or/and the sidewall of the sub-rectangular waveguide; the sidewall of the hollow coupling pipe close to the rectangular waveguide is connected with a coupling cavity with three opening ends; and the coupling cavity is communicated with the hollow coupling pipe, and is located between and communicated with the main rectangular waveguide and the sub-rectangular waveguide. The rectangular waveguide directional coupler provided by the invention is compact in structure and easy in processing, and has the outstanding advantage of low insertion loss in comparison with the common single-hole directional coupler, particularly in the millimeter wave band and the Terahertz wave band.

A physical layer device that communicates over a cable comprises a cable tester that determines a cable status, which includes an open status, a short status, and a normal status. The cable tester includes a pretest module that senses activity on the cable and selectively enables testing based on the sensed activity. A test module is enabled by the pretest module, transmits a test pulse on the cable, measures a reflection amplitude, calculates a cable length, and determines the cable status based on the measured amplitude and the calculated cable length. An insertion loss estimator communicates with the cable tester and estimates insertion loss of the cable. A return loss estimator communicates with the cable tester and estimates return loss of the cable based on gain parameters of the physical layer device.

Devices to enhance the reliability of optical networks and to reduce the cost of repair are disclosed in this invention. In particular, fiber optic union adapters with built-in protective isolation prevent a damaged, connectorized fiber optic cable from degrading other fiber optic terminations within the network should they be physically connected. The fiber optic union comprises a split sleeve with an interior channel and a fiber stub centrally located within the interior channel. The fiber stub prevents the ferrules of two different cables from making direct physical exchange but allows them to make efficient optical exchange. Opposite ends of the fiber stub are optically polished to enable physical contact to the ferrules of fiber optic cables with low insertion loss and low backreflection. Devices to achieve low loss isolated interconnection between cables containing dissimilar fiber types by use of a fiber taper are further disclosed.

There are provided a transmission/reception switching circuit which is small in insertion loss and harmonic distortion and allows an increase in the output power of a power amplifier and an electronic component for communication on which the transmission/reception switching circuit is mounted. As an element composing a transmission/reception switching circuit in a wireless communication system, series-connected FETs or a multi-gate FET are used in place of a diode. Gate resistors connected between the individual gate terminals and a control terminal are designed to have resistance values which become progressively smaller from the gate to which a highest voltage is applied toward the gate to which a lowest voltage is applied.

To provide an optical connector promoting reliability by reducing insertion loss of an optical fiber and downsized, there is provided an optical connector plug having a ferrule including a cylindrical member for the ferrule for holding an optical fiber and a flange member provided at a rear end portion of the cylindrical member for the ferrule, an urge spring provided on a side of a rear end portion of the flange member of the ferrule, and a plug housing for holding the ferrule and the urge spring directly at inside thereof and directly engaged with an optical connector adapter inserted with a front end portion of the ferrule to carry out optical connection, in which the plug housing is formed with a slit capable of inserting the optical fiber in a radius direction thereof at a portion of an outer periphery thereof over an axial direction.

A novel RF buffer circuit adapted for use with an RF switch circuit and method for switching RF signals is described. The RF switch circuit is fabricated in a silicon-on-insulator (SOI) technology. The RF switch includes pairs of switching and shunting transistor groupings used to alternatively couple RF input signals to a common RF node. The switching and shunting transistor grouping pairs are controlled by a switching control voltage (SW) and its inverse (SW_). The switching and shunting transistor groupings comprise one or more MOSFET transistors connected together in a “stacked” or serial configuration. The stacking of transistor grouping devices, and associated gate resistors, increase the breakdown voltage across the series connected switch transistors and operate to improve RF switch compression. A fully integrated RF switch is described including digital control logic and a negative voltage generator integrated together with the RF switch elements. In one embodiment, the fully integrated RF switch includes a built-in oscillator, a charge pump circuit, CMOS logic circuitry, level-shifting and voltage divider circuits, and an RF buffer circuit. Several embodiments of the charge pump, level shifting, voltage divider, and RF buffer circuits are described. The inventive RF switch provides improvements in insertion loss, switch isolation, and switch compression.

An amplifier circuit responsive to a power mode signal improves efficiency at low power levels without compromising efficiency at high power levels. At low power levels, high impedance is presented with suitable adjustment in the phase of the signal. Also, providing for predistortion linearization improves high power efficiency and switching the predistortion linearizer OFF at low power levels contributes little more than a small insertion loss. The power amplifier also uses a bias circuit incorporating a dual harmonic resonance filter to provide high impedance at a fundamental frequency and low impedance at a second harmonic. These properties are of particularly advantageous since amplifiers in cell-phones are used in low power modes most of the time although they are designed to be most efficient at primarily the highest power levels.

This invention relates to LANs at a customers' premise, especially to the HomePNA technique. The idea of the invention is that voice band terminals and HomePNA (HPNA) stations are hidden from a distribution network by a band division filter in a way that performance of ADSL is not degraded by presence of an HPNA LAN. The band division filter incorporates two subfilters: a POTS filter and an HPNA filter. The latter implements a band stop function maximizing insertion loss at the ADSL band The band division filter can be installed to needed telephone sockets.

A polarization independent (PI) interferometer design that can be built from standard optical components is described. Based upon a Michelson interferometer, the PI interferometer uses a 50/50 splitter and Faraday Rotator Mirrors (FM's). The interferometer achieves good optical characteristics, such as high extinction ratio (ER) and low insertion loss (IL). Lack of polarization sensitivity reduces interferometer construction tolerances and cost, enhances performance and utility, and expands the scope of interferometric based devices. Such characteristics can be used to construct flexible, high performance, polarization insensitive, multi-rate, self-calibrating, optical DPSK receivers, power combiners, optical filters and interleavers, all-optical switches, and cascaded interferometers. Since polarization is not maintained in standard fiber optic networks, a PI-DPSK receiver allows for use of more sensitive DPSK communications over fiber, without need for costly polarization control hardware. Other applications of PI interferometers include optical CDMA, secure communications, optical coherence tomography (OCT), and temporal gratings with ultra-precise timing.

The present invention overcomes problems associated with switch isolation, noise and crosstalk suppression, insertion loss, spurious reflections, wavelength tolerance, and compactness that are present in varying degrees in other add/drop systems. The present invention includes devices or components that include, but are not limited to high efficiency switchable gratings. In one embodiment of the invention, each of the “base” gratings have substantially identical spatial frequencies and each of the “vertex” gratings have substantially identical spacial frequencies. However, the “vertex” gratings have higher grating frequencies than the “base” gratings. In another embodiment of the invention, the “base” and “vertex” gratings have substantially the same grating frequencies. Further embodiments of the invention, for example, deal with multiple add/drop grating pairs, variations of fixed and switchable gratings, the use of grating pairs to spatially separate the wavelength division multiplexed components of input beams into individual beams, and the replacement of lenses and waveguides with detectors or emitters.

Integrating dual antennae into a single rigid assembly guarantees parallel alignment between the antennae and provides higher isolation with lower insertion loss than duplexing methods can achieve through a single antenna. The resulting higher performance at lower cost can benefit two-way communication systems using time division duplexing, frequency division duplexing, or polarization division duplexing; or combinations of these methods.

The invention describes method and apparatus for a mode converter enabling an adiabatic transfer of a higher order mode into a lower order optical mode within a photonic integrated circuit exploiting integrated semiconductor ridge waveguide techniques. As disclosed by the invention, such a mode conversion is achievable by using an asymmetric coupler methodology. In an exemplary embodiment of the invention, the invention is used to provide a low insertion loss optical connection between laterally-coupled DFB laser operating in first order mode and passive waveguide operating in the zero order optical mode. The integrated arrangement fabricated by using one-step epitaxial growth allows for a launch of the laser's light into the waveguide circuitry operating in the zero order lateral mode or efficiently coupling it to single-mode fiber, an otherwise high loss interface due to the difference in laser and optical fiber modes.