70results about How to "Minimizing insertion loss" patented technology

A model train and layout control system based on on-board sound and locomotive modules, new signaling methods, bi-directional communication, environmental sound, turnout control, train location methods, computer interaction and accessory control, by adding components to existing technology. AC power signal waveforms are variously altered to convey digital command words.

Wavelength-selective 1×N switches (WSSs) and N×N cross-connects (WSXCs) are described which are fabricated as monolithic or hybrid devices. In a preferred embodiment, the optic ports, dispersion elements, and collimating elements are formed on a single monolithic substrate. A micromirror and actuator are either fabricated within the substrate or a separate micromirror is utilized forming a hybrid WSS or WSXC. The optical elements can be formed in an opaque substrate layer (e.g., silicon, SOI, and so forth) or in an optically transparent layer of a PLC material (e.g., silica-on-silicon). Embodiments describe the use of linear and rotary comb drives for actuating front surface mirrors, or solid-immersion micromirrors (SIMs). The switching devices reduce system footprint while reducing or eliminating the need for alignment of the optical elements.

Systems and methods for an RF nulling scheme are provided. An RF nulling scheme can minimize the level of unwanted RF signal reflections entering the receiver without attenuating the desired signal response from an RFID tag. In one aspect of the RF nulling scheme a synthesizer signal can be split between a main path and a nulling path. In the nulling path the signal from the splitter can be routed through an electronically variable phase shifter and variable gain amplifier to create a nulling signal. The nulling signal can cancel the unwanted reflected signal. The phase or amplitude of the nulling signal can then be adjusted to improve cancellation as necessary.

Catheter apparatus comprises a coaxial cable having proximal and distal ends. The cable includes a hollow center conductor, an outer conductor and an electrically insulating layer between the conductors. An antenna is at the distal end of the cable, and a diplexer is connected to the cable, the diplexer including a transmit path for connecting the antenna to a transmitter which transmits first frequency signals and a receive path for connecting the antenna to a receiver which detects second frequency signals the diplexer isolating the signals on the two paths from one another. A transmission line connects the cable to the diplexer, the transmission line having a segment with a tubular inner conductor one end of which is connected to the center conductor and a second end of which is adapted for connection to a coolant source, the center and inner conductors forming a continuous coolant pathway.

An optical fiber coupler capable of providing a low loss, high coupling coefficient interface between conventional optical fibers and optical waveguide devices is provided. The novel coupler, which may be polarization maintaining, if a polarization maintaining preform is used in its fabrication includes a core, a cladding, a first end for interfacing with an optical fiber and a second end for interfacing with an optical waveguide device. The sizes of the core and cladding are gradually reduced from the first end to the second end in accordance with a predetermined reduction profile. Various parameters, such as refractive indices and sizes of the core and cladding and the reduction profile are selected to produce a low numerical aperture at the first end and a high numerical aperture at the second end, while advantageously minimizing insertion loss and maximizing the coupling coefficient at each end. In another embodiment, the novel coupler includes a secondary cladding which is also reduced between the first and second ends to improve the strength of the coupler structure at the second end. In yet another embodiment, one or two novel couplers are formed along with a chiral fiber based optical waveguide device as a single continuous element. The optical fiber preform used to fabricate the novel optical fiber coupler can be etched prior to fabrication to facilitate application of the reduction profile.

A tunable radio frequency (RF) filter is provided. The RF filter comprises a signal transmission path having an input and an output, a plurality of resonant elements disposed along the signal transmission path between the input and the output, and a plurality of non-resonant elements coupling the resonant elements together. The resonant elements are coupled together to form a stop band having a plurality of transmission zeroes corresponding to respective frequencies of the resonant elements, and at least one sub-band between the transmission zeroes. The non-resonant elements comprise at least one variable non-resonant element for selectively introducing at least one reflection zero within the stop band to create a pass band in one of the sub-bands(s). The variable non-resonant element(s) may be configured for displacing the reflection zero(es) along the stop band to selectively move the pass band within the one sub-band or within selected ones of the sub-bands.

A broadband multiple input, multiple output switch matrix. The switch matrix comprises multiple crosspoint switch element tiles. Each tile comprises RF MEMS switches disposed on a substrate to provide a crosspoint switching capability. The crosspoint switch element tiles are disposed in a flip-chip manner on the upper side of an RF substrate that provides RF connectivity between the various crosspoint switch element tiles. A bias line substrate disposed on the lower side of the RF substrate receives control signals for the crosspoint switch element tiles and routes the signals through the RF substrate using vias in the RF substrate.

A tunable radio frequency (RF) filter is provided. The RF filter comprises a signal transmission path having an input and an output, a plurality of resonant elements disposed along the signal transmission path between the input and the output, and a plurality of non-resonant elements coupling the resonant elements together. The resonant elements are coupled together to form a stop band having a plurality of transmission zeroes corresponding to respective frequencies of the resonant elements, and at least one sub-band between the transmission zeroes. The non-resonant elements comprise at least one variable non-resonant element for selectively introducing at least one reflection zero within the stop band to create a pass band in one of the sub-bands(s). The variable non-resonant element(s) may be configured for displacing the reflection zero(es) along the stop band to selectively move the pass band within the one sub-band or within selected ones of the sub-bands.

A tunable RF filter comprises a signal transmission path having an input and output, a plurality of resonant elements disposed along the signal transmission path between the input and output, and a set of non-resonant elements coupling the resonant elements together to form a stop band having a plurality of transmission zeroes corresponding to respective frequencies of the resonant elements, and at least one sub-band between the transmission zeroes. The set of non-resonant elements comprises a first plurality of non-resonant elements respectively coupled in parallel with the resonant elements, and a second plurality of non-resonant elements respectively coupled in series with the resonant elements. The first plurality of non-resonant elements comprises at least one variable non-resonant element for selectively introducing at least one reflection zero within the stop band to create a pass band in one of the one sub-band(s) without varying any of the second plurality of non-resonant elements.

A variable power divider and method can vary the RF power between ports in a high power and multi-carrier RF environment, such as is used in controlling signals sent and received in a base station antenna. The variable power divider can include a single-control phase shifter and a hybrid power divider. The single-control phase shifter can comprise a three-port device having a single input port and two output ports. The single-control phase shifter can further comprise a variable adjuster that can change or adjust the phase between two RF signals. The hybrid power divider can comprise a four-port device having two input ports and two output ports. Both the single-control phase shifter and the hybrid power divider can comprise substantially planar structures that are suitable for high-speed manufacturing. The output ports of the hybrid power divider can be coupled to various devices such antennas or power absorbing elements.

An extension housing (C) for a cable TV multi-tap device is made up of extension tubes (A) in coaxially aligned relation to one another for the purpose of providing wider bandwidth subscriber multi-taps with a longer extension coaxial connector to span the distance between a TV coaxial cable ends without affecting performance. An RF signal connector (H) is inserted in each tube having a dielectric insulator (D) at one end, an elongated conductor (15) having a bore (17) extending through its greater length and longitudinally split segments (14) surrounding the bore for insertion of a conductor pin (10) extending from a cable connector at the end of the extension tube and inserted through the dialectric insulator into the bore and a second conductor pin (16) extending from the elongated conductor into contact with a face plate connector (G) in the housing. In one form of invention the second conductor pin extends through a second dielectric insulator (E) into contact with the face place connector. In another form of invention, a printed circuit board (50) is interposed between the second conductor pin (10') and the connector (H') to establish a predetermined impedance in the RF signal connector.

A model train and layout control system based on on-board sound and locomotive modules, new signaling methods, bi-directional communication, environmental sound, turnout control, train location methods, computer interaction and accessory control, by adding components to existing technology. AC power signal waveforms are variously altered to convey digital command words.

According to the invention the coupling unit comprises a ferromagnetic core (30) which encloses a conductor through which a low frequency current (1) is circulating in order to inject thereon a high frequency signal, is characterised in that current (1), circulating through the conductor or the magnetic field (3) produced in the coupling unit, is detected, and a compensating current is obtained based on the value obtained in the detection carried out, and the compensating current obtained in the coupling unit is injected through a low pass filter (9) to produce a magnetic field (4) equal and opposite to that produced by current (1) of the conductor in said coupling unit, and thereby avoiding the saturation of the magnetic care (30) without adding insertion loss. In general it is applied to communication systems which require the injection of a radiofrequency signal on a conductor, and in particular in systems which use the electricity grid as the transmission medium.

A bi-directional optical transmission system according to the present invention provides transport of x optical channels over n nodes. The system supports two-way transport of the x channels over a single fiber connecting each of the nodes in sequence. The system is advantageous in that only two optical transmission bands are utilized in order to achieve minimal loss in the separation of bands. The use of only two bands permits the utilization of low-loss wide band thin film optical filters to combine and separate the signals at each node. A reflection port of this filter is used to carry oppositely directed signals of the second band from the bi-directional fiber to an optical amplifier for the second band. An alternate arrangement of the optical filters in the two separate bands is chosen to maximize the optical performance of the overall system and significantly reduce insertion losses.

An optical modulator includes a waveguide Mach-Zehnder interferometer having a first and a second input and a first and a second output, a feedback waveguide segment connecting the second output with the second input, and a traveling-wave electrode; wherein the Mach-Zehnder interferometer, feedback waveguide segment and traveling-wave electrode are substantially arranged at or adjacent the perimeter of a smooth curve defining a closed geometric figure, the traveling-wave electrode extending along at least 50% of the length of the perimeter of the smooth curve.

A transmission line feed for a surface wave medium having a dielectric substrate with an array of electrically conductive patches formed thereon. The transmission line feed includes a microstrip substrate, the microstrip substrate having a first permittivity which is lower than a second permittivity of the dielectric substrate of the surface wave medium, the microstrip substrate abutting against the dielectric substrate of the surface wave medium; a tapered microstrip disposed on the microstrip substrate, the tapered microstrip tapering from a relatively narrow end to a relatively wide end, the relative wide end terminating where the microstrip substrate abuts against the surface wave substrate; and an adapter for coupling a transmission line to the relatively narrow end of the tapered microstrip.

Process and device for compensating the low frequency magnetic field in an inductive signal coupling unit. According to the invention the coupling unit comprises a ferromagnetic core (30) which encloses a conductor through which a low frequency current (1) is circulating in order to inject thereon a high frequency signal. Current (1), circulating through the conductor or the magnetic field (3) produced in the coupling unit, is detected, and a compensating current is obtained based on the value obtained in the detection carried out, and the compensating current obtained in the coupling unit is injected through a low pass filter (9) to produce a magnetic field (4) equal and opposite to the produced by current (1) of the conductor in the coupling unit, and thereby avoiding the saturation of the magnetic core (30) without adding insertion loss. In general the invention is applied to communication systems which require the injection of a radio frequency signal on a conductor, and in particular in systems which use the electricity grid as the transmission medium.

A monitoring system for high-frequency circuits which minimizes the insertion loss of additional monitoring circuits while requiring only a small space. An input coupler is placed at the input of a high-frequency circuit whose frequency response is to be monitored. The input coupler has a space where a given high-frequency probing signal can propagate, and it combines this propagating signal with a given electrical input signal. The combined signal is processed by the high-frequency circuit, and the resulting signal is supplied to an output coupler. The output coupler has a space for propagation of a high-frequency probing signal component contained in the received combined signal. The output coupler extracts this propagating signal component for the purpose of monitoring.

A waveguide diplexer having an electric plane T-junction structure with a resonant iris is disclosed. The waveguide includes: a waveguide having a predetermined shaped cross section; a transmitting filter for preventing to generate a harmonic band and a higher mode in a receiving band by changing impedance to have a low pass characteristic inside the waveguide; a receiving filter for minimizing an insertion loss by changing impedance to have a bandpass characteristic inside the waveguide; an electric plane T-junction for isolating / combining a transmitting signal and a receiving signal without electric interference by connecting the transmitting filter and the receiving filter, and minimizing interference of a frequency transmitted / received through the transmitting filter and the receiving filter; and an impedance converter for differentiating a transmitting port and a receiving port with minimum electric interference to the transmitting filter and the receiving filter by changing the impedance.

A high-frequency module constituted by an integral laminate for handling a plurality of transmitting / receiving systems having different passbands comprises (a) a switch module part for branching higher-frequency signals and lower-frequency signals and switching connection to the transmitting systems and the receiving systems, (b) a high-frequency amplifying circuit module part, and (c) a phase-adjusting circuit disposed between the switch module part and the high-frequency amplifying circuit module part, wherein the phase matching between the switch module part and the high-frequency amplifying circuit module part via the phase-adjusting circuit is adjusted to conjugate matching in a fundamental frequency band, while it is adjusted in a nonconjugate matching range in n-th frequency bands, wherein n is an integer of 2 or more.

A loudspeaker protection circuit comprises a rectification stage for receiving an input audio signal and producing a rectified output signal, a detection stage for passing the rectified output signal when the rectified output signal is greater than a predetermined level, a timing stage for receiving the rectified output signal from the detection stage and producing a time-varying charge signal, a regulation stage for producing a regulated output signal based on the input audio signal, an actuator stage for actuating a switch based on the time-varying charge signal and the regulated output signal, and an attenuation stage for attenuating an output audio signal when the switch is actuated.

A signal-line socket includes a housing, a circuit board, a socket terminal and a signal pin. The housing has a socket hole for receiving a plug of an external signal line. The circuit board is disposed in the housing and has room for mounting thereon an analog circuit chip. The socket terminal is electrically connected to the circuit board and exposed from the socket hole to be electrically connected to the plug of the external signal line for connecting the network signal line to the analog circuit chip. The signal pin is electrically connected to the circuit board and exposed from the housing to be electrically connected to a main board of a computer for connecting the analog circuit chip to the main board of the computer.

A monolithic photonic integrated circuit (PIC) chip where the active waveguide cores of the modulated sources of the PIC are multiple quantum wells (MQWs) and the passive waveguide cores of an optical combiner are a bulk layer or material. The cores of the waveguide cores may be a quaternary such as InGaAsP or InAlGaAs.

Methods and system for using a multifunctional filter to minimize insertion loss in a multimode communications system are described. Specifically described is a multifunctional filter that is configurable to operate in a bandpass mode when a first type of signal is propagated through the multifunctional filter, and to operate in a lowpass mode when a second type of signal is propagated through the multifunctional filter. The multifunctional filter presents a lower insertion loss to the second type of signal when operating in the lowpass mode than in the bandpass mode.

A waveguide diplexer having an electric plane T-junction structure with a resonant iris is disclosed. The waveguide includes: a waveguide having a predetermined shaped cross section; a transmitting filter for preventing to generate a harmonic band and a higher mode in a receiving band by changing impedance to have a low pass characteristic inside the waveguide; a receiving filter for minimizing an insertion loss by changing impedance to have a bandpass characteristic inside the waveguide; an electric plane T-junction for isolating / combining a transmitting signal and a receiving signal without electric interference by connecting the transmitting filter and the receiving filter, and minimizing interference of a frequency transmitted / received through the transmitting filter and the receiving filter; and an impedance converter for differentiating a transmitting port and a receiving port with minimum electric interference to the transmitting filter and the receiving filter by changing the impedance.

An optical fiber connector in which a terminus assembly (20) can be keyed so it is always installed in a predetermined rotational position about the axis of a terminus-receiving passage (18) of a housing (12). When a terminus rotational position is found that results in minimal insertion loss, a noncircular index sleeve (40) is placed around the terminus body (24) and fixed thereto. An indexing plate (70) is installed in the connector housing, with indexing passage portions (72) that receive the index sleeve at only a single rotational position of the indexing sleeve about the passage axis.

A system and method for detection of coking in a fuel. The system including a fuel system for delivery of fuel, a fuel contamination sensor having a contamination detection sensor with input and output transducers immersed in the fuel, a controller in operable communication with the fuel contamination sensor, the controller configured to execute a method for detection of coking in fuel. The method including generating an excitation signal for the contamination detection sensor, receiving at a controller operably connected to the contamination detection sensor, a sensor output signal from the output transducer, comparing the sensor output signal with the excitation signal, diagnosing a condition of the fuel based on a the comparing, and indicating a condition of coking based on the diagnosing. The system also includes an enunciator to indicate the detection of coking in the fuel.