1936 results about "Directional coupling" patented technology

An optical fiber for transmitting radiation comprising two or more core regions, two or more core regions, each core region comprising a substantially transparent core material and having a core refractive index, a core length, and a core diameter, wherein said core regions are arranged within a cladding region, said cladding region comprising a length of first substantially transparent cladding material, having a first refractive index, wherein said first substantially transparent cladding material has an array of lengths of a second cladding material embedded along its length, wherein the second cladding material has a second refractive index which is less than said first refractive index, such that radiation input to said fiber propagates along at least one of said core regions. The cladding region and the core regions may be arranged such that radiation input to said optical fiber propagates along one or more said lengths of said core regions in a single mode of propagation. The optical fiber may be used as a bend sensor, a spectral filter or a directional coupler. The invention also relates to a method of manufacturing a multicore optical fiber.

Apparatus for transmitting a digital signal within, for example, an integrated circuit includes a signal transmission line with a directional coupler at one or both ends. The directional coupler blocks the direct-current component of the digital signal while transmitting the alternating-current component, including enough higher harmonics to transmit a well-defined pulse waveform. A suitable directional coupler consists of two adjacent line pairs in materials with different dielectric constants. The apparatus may also include a driver of the inverter type, a receiver of the differential amplifier type, a terminating resistor, and a power-ground transmission line pair for supplying power to the driver. An all-metallic transmission-line structure is preferably maintained from the output interconnections in the driver to the input interconnections in the receiver.

An embodiment of the present invention provides an apparatus, comprising an input port and a dynamic impedance matching network capable of determining a mismatch at the input port and dynamically changing the RF match by using at least one matching element that includes at least one voltage tunable dielectric capacitor. The matching network may be a “Pi”, a “T”, or “ladder” type network and the apparatus may further comprise at least one directional coupler capable of signal collection by sampling a portion of an incident signal, a reflected signal or both. In an embodiment of the present invention, the apparatus may also include a control and power control & logic unit (PC LU) to convert input analog signals into digital signals and sensing VSWR phase and magnitude and processing the digital signals using an algorithm to give it a voltage value and wherein the voltage values may be compared to values coming from the coupler and once compared and matched, the values may be passed to a Hi Voltage Application Specific Integrated Circuit (HV ASIC) to transfer and distribute compensatory voltages to the matching network elements.

A method for tuning a transmitter in order to improve impedance matching to an antenna or to intermediate radio frequency stages uses an error detector that senses a deviation of the amplitude or phase angle of a load current of a power amplifier driver or of a power amplifier. A controller calculates a correction and dynamically adjusts tunable transmitter parameters, which may include values of components in matching networks or bias voltages in the power amplifier or the power amplifier driver, so as to reduce the deviation and thereby improve the impedance matching. The load current of the power amplifier may alternatively be sensed by measuring the duty cycle of its switching mode power supply. A transmitter having a power amplifier and one or more tunable circuit elements incorporates an error detector that senses the amplitude or phase of a load current and a controller that adjusts one or more tunable parameters to reduce impedance mismatch. An integrated circuit device suitable for use in a transmitter includes a power amplifier driver circuit and a detector circuit capable of sensing a load current, and a controller circuit that can adjust tunable parameters either within or external to the integrated circuit. By eliminating directional couplers and integrating the detectors and power amplifier drivers, the size, complexity, and cost of wireless transceivers can be reduced, while efficiency and power consumption are improved through the dynamic adjustment of operating points and impedance matching.

A passive directional coupler is receptive of VoIP, Internet, and video/data signals, and is used in a CATV amplifier device to couple the video/data signals from a cable drop input port to the input terminal of an amplifier, and to passively bypass the VoIP and Internet signals to a modem port, for insuring continuous connection of the VoIP and Internet signals to the a modem of a user connected to the modem port, regardless of the loss of power to the amplifier or the failure of the amplifier, in one embodiment of the invention. In another embodiment, a switching circuit is responsive to the loss of power to the amplifier, for electrically connecting a 75 ohm resistor between a source of reference potential, and the common connection between the directional coupler and the amplifier, for maintaining a 75 ohm impedance at the directional coupler output to the common connection. In a preferred embodiment, the switching circuit also opens the common connection between the directional coupler and amplifier, upon the loss of power to the amplifier.

Proximity of a user body part can be detected by measuring the effects such proximity has on antenna impedance mismatches. The amount of mismatch affects the amount of RF signal energy reflected back into a transmission line connecting the antenna to a RF signal source. A directional coupler has a main line electrically connected to the transmission line, as well as a coupled line. The directional coupler produces a signal on its coupled line in relation to the magnitude of reflected energy on the transmission line; the amount of reflected energy varies in response to how well the antenna impedance matches the transmission line impedance. A signal detector is electrically connected to the coupled line, and responds to signals produced in the coupled line by the main line. The signal detector output is then used to determine whether a body part is in proximity. Other aspects the invention include an adaptive algorithm to adjust a threshold for proximity determination.

An embodiment of the present invention provides an apparatus, comprising an input port and a dynamic impedance matching network capable of determining a mismatch at the input port and dynamically changing the RF match by using at least one matching element that includes at least one voltage tunable dielectric capacitor. The matching network may be a “Pi”, a “T”, or “ladder” type network and the apparatus may further comprise at least one directional coupler capable of signal collection by sampling a portion of an incident signal, a reflected signal or both. In an embodiment of the present invention, the apparatus may also include a control and power control & logic unit (PC LU) to convert input analog signals into digital signals and sensing VSWR phase and magnitude and processing the digital signals using an algorithm to give it a voltage value and wherein the voltage values may be compared to values coming from the coupler and once compared and matched, the values may be passed to a Hi Voltage Application Specific Integrated Circuit (HV ASIC) to transfer and distribute compensatory voltages to the matching network elements. Additional embodiments are disclosed.

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.

The invention relates to a directional coupling communication apparatus where the coupling impedance can be easily matched to reduce reflections, and thus, the speed of communication channels is increased as compared to that with inductive coupling, and at the same time, the reliability of communication is improved by increasing the signal intensity. Modules having a coupler where an input/output connection line is connected to a first end, and either a ground line or an input/output connection line to which an inverse signal of a signal to be inputted into the input/output connection line connected to the above-described first end is inputted is connected are layered on top of each other so that the couplers are couplers to each other using capacitive coupling and inductive coupling.

Tunable add/drop optical device for injecting or extracting (add/drop) at least a selected optical channel or carrier wavelength in or from a set of multiplexed channels or carriers of different wavelengths comprising a plurality of directional couplers (AD1 . . . AD6) and a plurality of phase-shift stages (SF1 . . . SF5) alternately connected in cascade, wherein each phase-shift stage defines a certain optical path length difference (DELTAL1 . . . DELTAL5) between two distinct optical paths of the stage. The tuning is performed modifying the refraction index of one path of said phase shift stages by means of Joule effect heating strips (L1 . . . L5) or by means of metallic field plates adapted to receive a signal suitable to modify the electric field intensity. The first two phase-shift stages of said plurality of phase-shift stages have differences of length of optical paths different from each other and in a preestablished ratio while the remaining phase-shift stages have differences of length of optical paths identical. It is thus possible to provide a device having an exceptionally flat cross response characteristic, substantially free of ripple due to an inevitable truncation of the Fourier expansion series.

An optical waveguide includes a substrate in the shape of a flat plate; lower clad that is disposed on the substrate; and a core that is disposed on the lower clad and transmits light. The optical waveguide includes a first optical waveguide and a second optical waveguide. The first optical waveguide includes a first core on the lower clad, and is disposed so as to extend along a direction in which the light travels to a first position. The second optical waveguide includes a second core on the lower clad, is disposed so as to extend along a direction in which the light travels to a second position, and has a lower relative refractive index difference than the first optical waveguide. The first optical waveguide and the second optical waveguide form, between the first position and the second position, a layer structure where the first core and the second core are disposed such that the first core is positioned a predetermined distance away from the second core in a direction perpendicular to the substrate. At least either the first optical waveguide or the second optical waveguide includes a mode coupling section and a mode conversion section. The mode coupling section includes a directional coupler to conduct the mode coupling of the first core and the second core between the first position and the second position. The mode conversion section is connected to the mode coupling section, and has a tapered core structure to adjust the mode diameter of the first core to the mode diameter of the second core.

An electronic part for a high frequency power amplifier is provided which is designed to constitute at least a part of a wireless communication system for performing feedback control by detecting an output power, and which can miniaturize a directional coupler. Also, the electronic part permits control of the output power with high accuracy without having any influence on a monitor voltage by a reflected wave propagating through a line of the directional coupler. The directional coupler includes a subline disposed in parallel to and in the vicinity of a part of a main line of an impedance matching circuit on the last output stage side of a power amplifier circuit, a capacitance element connected to between the main line and the subline, and a resistor element connected to between a constant potential point and a termination side of the subline. An output power detection circuit includes a first detection circuit for detecting an alternating current signal taken from a beginning side of the subline, a second detecting circuit for detecting an alternating current signal taken from a termination side of the subline, and a subtracting circuit for performing subtraction between an output of the first detection circuit and an output of the second detection circuit.

The present invention provides a compact weakly coupled directional coupler combined with an integrated impedance transformation and matching circuit where the impedance transformation and matching circuit facilitates the fabrication of a highly miniaturized directional coupler with optimum electrical performance where the physical dimensions of the coupled transmission lines fall inside the constraints of the fabrication process.

The invention relates to an optical device including a passive high confinement waveguide, such as of silicon-rich silicon nitride, on an electro-optic substrate, like lithium niobate, optically coupled to a waveguide in the electro-optic substrate. A wide range of electro-optic devices are enabled by this high confinement waveguide structure, including: directional couplers, compact tap couplers, folded electro-optic devices, electro-optic modulators including ring resonators, electro-optic gratings. Further applications enabled by the present invention include hybrid passive planar lightwave circuits (PLC) integrated with electro-optically active waveguides, using the high confinement waveguide as an intermediary waveguide to transfer optical power between the passive and active components.

A resonator structure includes an input waveguide and an output waveguide. In one embodiment, the resonator structure also includes at least one resonator that couples the input waveguide to the output waveguide and a directional coupler that optically couples the input waveguide to the output waveguide. In another embodiment, the resonator structure includes a plurality of ring resonators that couple the input waveguide to the output waveguide. The plurality of ring resonators include a sequence of ring resonators that form a coupling loop. Each ring resonator in the sequence is coupled to at least two other ring resonators in the sequence and the first ring resonator in the sequence is coupled to the last ring resonator in the sequence so as to form the coupling loop.

A directional coupler includes capacitive elements electrically connected to a coupled port and an isolated port, respectively, for a coupled line on a chip (on-chip). The capacitive elements serve as matching capacitive elements and may be MIM (Metal Insulator Metal) capacitors on a substrate. A first end of a first of the capacitive elements is connected between the coupled port and the coupled line and a second end is grounded. A first end of a second of the capacitive elements is connected between the isolated port and the coupled line and a second end is grounded.

A feedforward amplifier includes a power divider for dividing the input signal into first and second signals. The first signal is processed in a first path that includes, in sequence, a first vector adjuster, a main amplifier, a directional coupler and a delay circuit. The second signal is delayed in a second path that includes, in sequence, another delay circuit, a first power combiner and an auxiliary amplifier block. The first power combiner combines the first signal, by way of a coupling port from the directional coupler, with the second signal to provide a combined signal into the auxiliary amplifier block. The auxiliary amplifier block further divides the second signal into two divided signals, each having a respective non-overlapping frequency band. The two divided signals are respectively vector adjusted, amplified, and then recombined. The recombined signal is then recombined with the processed signal in the first path to provide the desired output signal.

In an array-antenna-equipped communication apparatus, a part of a transmission signal after passing through a radio wave transmitter is branched by a directional coupler, combined by a combiner, converted to a baseband signal by a receiver for calibration, analog-converted by an analog-to-digital converter, and input to an adaptive controller as a feedback signal. The adaptive controller calculates a calibration value that minimizes the power of an error signal representing a difference between the feedback signal and a reference signal, which is the transmission signal before passing through the radio wave transmitter, and outputs the calibration value to a corrector for calibration.

In a chromatic dispersion compensator, an optical signal directing unit such as an optical circulator or a directional coupler having a first, second, third and fourth ports. The optical signal directing unit directs an optical signal inputted from one of the ports to another port of the ports. A reflection-type compensator including a dispersion compensating fiber, a reflecting portion and changing unit for changing a polarization direction of a reciprocating signal light, in which the dispersion compensating fiber is connected to the reflecting portion via the changing unit. An input transmission path which is connected to the first port; and an output transmission path which is connected to the fourth port so that the signal light is outputted from the fourth port. The reflection-type compensating unit is connected to one of the second and third ports, and the chirped grating is connected to the other port.