1284results about How to "Improving Impedance Matching" patented technology

An apparatus for launching a surfacewave onto a single conductor transmission line provides a launch including a flared, continuously curving cone portion; a coaxial adapter portion; a wire adapter portion for contacting the wire conductor which allows for a multiplicity of wire dimensions for either insulated or uninsulated wire, or a tri-axial wire adapter device enabling non-contacting coupling to a wire; and a longitudinal slot added to the flared cone, wire adapter, and coaxial adapter portions of the launch to allow direct placement of the launch onto existing lines, without requiring cutting or threading of those lines for installation.

A microstrip antenna that can be linear, co-circular, or dual-circularly polarized having co-planar radiating elements and operating at dual frequency bands wherein an inner radiating element is surrounded by and spaced from an outer radiating element. Each radiating element resonates at a different frequency. In one embodiment of the invention a feed network has a single, cross-shaped, feed line that is positioned between the inner and outer radiating elements and capacitively coupled to the inner and outer radiating elements. In another embodiment of the present invention, the radiating elements are fed separately by first and second feed networks each having a plurality of feed points. The radiating elements each have one active feed point that is either directly or indirectly coupled to its respective feed network.

A broadband antenna structure (10) for a transponder of a radio frequency identification system comprises —a loop resonator (12) with a feedpoint (14) for connecting with an electronic circuit (16), and —a dipole resonator (18) electrically connected to the loop resonator (12) and comprising two electrically isolated legs (20, 22).

A dual-band resonator with compact size, such as a resonant type dual-band antenna, which uses an anisotropic metamaterial is described. The artificial anisotropic medium is implemented by employing a composite right / left-handed transmission line. The dispersion relation and the antenna physical size only depend on the composition of the unit cell and the number of cells used. By engineering the characteristics of the unit cells to be different in two orthogonal directions, the corresponding propagation constants can be controlled, thus enabling dual-band antenna resonances. In addition, the antenna dimensions can be markedly minimized by maximally reducing the unit cell size. A dual-band antenna is also described which is designed for operation at frequencies for PCS / Bluetooth applications, and which has a physical size of 1 / 18λ0× 1 / 18λ0× 1 / 19λ0, where λ0 is the free space wavelength at 2.37 GHz.

The present invention provides a planar antenna having a scalable multi-dipole structure for receiving, and transmitting high-frequency signals, including a plurality of opposing layers of conducting strips disposed upon either side of an insulating (dielectric) substrate. The dipoles are bifurcated between sides of a substrate on which the dipoles are disposed. A feed line is balanced to a co-axial cable and feeds one half of the bifurcated dipoles, and an independent feed line is connected to the other half of the bifurcated dipoles. Sets of the dipoles are arranged symmetrically around a center axis of the feed lines. The sets of dipoles are in series with other sets of dipoles. The antenna is ideally suited for operation in the 5.15-5.35 GHz RF band.

The invention comprises novel microwave antennas wherein the microwave field profile generated by an antenna is tailored and optimized for a particular clinical application. The antennas disclosed herein incorporate one or more additional elements called shaping elements that use unique properties of microwaves such as interaction of a microwave field with one or more conductive or non-conductive elements to shape or redistribute the microwave field. Such shaping elements may be used to reduce the undesired backward coupling of the emitted microwave field to the transmission line. Such shaping elements may be used to increase the power efficiency of the antenna. The invention also discloses devices and methods for treating tissue with microwave energy emitted from the antennas for use in applications such as destroying a soil tissue by microwave ablation.

A piezoelectric micromachined ultrasonic transducer comprising a substrate and a first dielectric film formed on the substrate. An opening having a sidewall is formed through the substrate and first dielectric film. A bottom electrode is formed on the first dielectric film spanning the opening. A piezoelectric element is formed on the bottom electrode. A second dielectric film surrounds the piezoelectric element. A conformal insulating film is formed on the sidewall of the opening. A conformal conductive film is formed in contact with the bottom electrode and on the sidewall of the opening, wherein an open cavity is maintained in the opening. A top electrode is formed in contact with the piezoelectric element.

A surgical antenna for radiating microwave energy (e.g. frequency 500 MHz to 60 GHz) from a e.g. ceramic insertion tip (60) into biological tissue is disclosed. The tip is provided at the end of an elongate body which delivers the microwave energy to the tip via an inner conductor (30), an outer conductor (20) surrounding the inner conductor and a dielectric material (50) therebetween. The impedance of the insertion tip (60) is selected to improve impedance matching with the complex conjugate of the complex impedance of the tissue at a treatment frequency. For example the insertion tip may act as or include at least one quarter wavelength impedance transformer. By closely matching the antenna's impedance to the tissue, dynamic tuning (if used) can be performed much more efficiently. Impedance matching at the tip can also focus the radiated energy distribution.

The invention relates to a device for electrically connecting a coaxial line to a printed circuit card having at least two conductor tracks each extending to an edge of said card. The device has an outer contact and a center contact received inside the outer contact. The outer contact has a portion for connection to the card that is substantially tubular in shape, being provided with two diametrically-opposite slots which subdivide said connection portion into two jaws arranged to pinch between them said card inserted via its edge between said jaws, and the center contact has portion for connection to the card in the form of a clip into which the edge of the card is engaged when the card is inserted between the two jaws of the outer contact.

Intravascular device for matching impedances of portions of an intravascular circuit and limiting RF signal-induced heating of intravascular conductors. An intravascular device includes alternating conductive and dielectric layers and an electrically conductive coil in a configuration that effects an impedance-matching circuit. Another embodiment of an intravascular device has cylindrical inner and outer walls formed of an expandable, electrically conductive material, the inner and outer walls being separated by a compressible dielectric material. Varying the pressure in the lumen defined by the inner wall changes the spacing between the inner and outer walls, thereby changing the capacitance between the inner and outer wall. Another embodiment of an intravascular device includes one or more coaxial chokes for limiting heating caused by currents induced by RF signals. A conductive shield of the choke is formed of a conductive polymer to further reduce heating effects. Other embodiments include different transmission lines and antenna structures.

A microwave ablation probe for providing microwave energy to tissue is disclosed. The probe includes a feedline having an inner conductor, a secondary inner conductor, an insulating spacer, and an outer conductor. The inner conductor is slidably disposed within the secondary inner conductor. The feedline also includes a radiating portion having an extruded portion of the inner conductor centrally disposed therein, wherein longitudinal movement of the inner conductor relative to the feedline tunes the radiating portion.

An electronic circuit device has a high-density mount board, on which are disposed a microcomputer, a random access memory, a programmable device which is a variable logic circuit represented by FPGA, and an electrically-rewritable nonvolatile memory which can store the operation program of the microcomputer. The high-density mount board has external mounting pins on the bottom surface so as to be mounted on a mother board in the same manner as a system on-chip multi-chip module. With an intended logic function being set on the programmable device, a hardware-based function to be realized by the electronic circuit device is simulated. With an operation program being written to the nonvolatile memory, a software-based function to be realized is simulated. Consequently, the device facilitates the debugging at early stages of system development, configures a prototype system, and contributes to the time reduction throughout the system development, prototype fabrication and large-scale production.

The present invention relates to a multiband folded loop antenna comprising a dielectric substrate, a ground plane, a radiating portion and a matching circuit. The ground plane is located on the dielectric substrate and has a grounding point. The radiating portion comprises a supporter, a loop strip, and a tuning patch. The loop strip has a length about a half-wavelength of the central frequency of the antenna's first resonant mode. The loop strip has a feeding end and a grounding end, with the grounding end electrically connected to the grounding point on the ground plane. The loop strip is folded into a three-dimensional structure and is supported by the supporter. The tuning patch is electrically connected to the loop strip. The matching circuit is located on the dielectric substrate with one terminal electrically connected to the feeding end of the loop strip and another terminal to a signal source.

Systems and methods which utilize a symmetrical partially coupled microstrip slot feed patch antenna element configuration to provide highly decoupled dual-polarized wideband patch antenna elements are shown. Embodiments provide a microstrip slot feed configuration in which a slot of a first signal feed is centered with respect to the patch and further provide a microstrip slot feed configuration in which slots of a second signal feed are symmetrically disposed with respect to the center of the patch and at positions near the edges of the patch. The microstrip feed utilized in communicating signals with respect to the slots of the second signal feed is adapted to provide signals of substantially equal amplitude and 180° out of phase with respect to each other according to embodiments. The second signal feed configuration utilized according to embodiments provides partial coupling between the patch and the second signal feed.

A method of converting electrical signals into mechanical vibration by means of a transducer in the human ear, an ear canal transducer and a headset wherein a sensation of hearing is achieved by exciting the tissue of the ear canal directly with said transducer, whereby the vibrations propagate to the tympanic membrane and into the human sound sensing organs.

The present invention discloses a dual-frequency antenna, which comprises a radiation conductor, an extension conductor, a feeder member, a short-circuit member, and a ground plane. The radiation conductor has a first terminal and a second terminal, which are arranged close to each other but do not contact each other. The extension conductor is connected to the second terminal and disposed along the contour of the first terminal to have a gap between the extension conductor and the first terminal. The feeder member is connected to the radiation conductor. One end of the short-circuit member is connected to the radiation conductor, and the other end is connected to the ground plane. The radiation conductor generates a low-frequency resonant mode and a first high-frequency resonant mode. In the present invention, a single radiation conductor generates two resonant modes to form the operational frequency bands of the dual-frequency antenna.

A radar level gauge system, for determining a filling level of a product contained in a tank, the radar level gauge system comprising: a transceiver for generating, transmitting and receiving electromagnetic signals; a probe electrically connected to the transceiver at a probe-transceiver connection and arranged to extend towards and into the product contained in the tank, for guiding a transmitted signal from the transceiver towards a surface of the product, and for returning a surface echo signal resulting from reflection of the transmitted signal at the surface back towards the transceiver; an impedance matching device arranged to extend along a portion of the probe inside the tank, an extension of the impedance matching device, in a direction perpendicular to the probe, decreasing along the portion of the probe with increasing distance from the probe-transceiver connection, to thereby provide impedance matching between an impedance of the probe-transceiver connection and an impedance of the probe; and processing circuitry connected to the transceiver for determining the filling level based on the surface echo signal.

Cascade low-pass filters are useful in attenuating the xDSL band in a POTS splitter. The design of the low-pass filter is a sixth-order filter having two stages. A first stage includes a fourth-order filter, preferably with a stop-band frequency of approximately 48 kHz. A second stage includes a second-order filter in cascade with the fourth-order filter. For this filter, the stop-band frequency is preferably approximately 29 kHz. The inductance value of the second stage is relatively small in comparison to the inductance values of the first stage. In this manner, improvements in xDSL band attenuation are facilitated with little or no eroding of the voice band performance such as insertion loss, pass-band attenuation and return loss.

The present invention is related to a coupled-fed multi-band loop antenna. The antenna comprises a dielectric substrate, a ground plane located on the dielectric substrate and has a grounding point, a radiating portion which comprise a supporter, a coupling trip and a loop strip, and a matching circuit. The coupling strip and loop strip are both located on the supporter, with the coupling strip surrounded by the loop strip. The length of loop strip is about 0.25 wavelength of the antenna's first resonant mode. The loop strip has a first end paralleling with the coupling loop, a second end and a shorting point near the second end and electrically connected to the grounding point on the ground plane. The matching circuit is on the dielectric substrate. One terminal of the matching circuit is connected to the coupling strip, and the other is connected to a signal source.

An optical transmitter and / or a constituent electro-optic transducer driver that performs active matching. The transducer driver performs active matching using a voltage step down through one base-emitter bipolar transistor, followed by a step up approach through the base-emitter of another bipolar transistor, thereby allowing for lower supply voltages. Furthermore, the voltage drop across the source resistor is minimal by using an operation amplifier in a feedback configuration, thereby further encouraging operability with low supply voltages. The electro-optic transducer driver is also beneficial in that it has high AC-coupling efficiency of the modulation current to the electro-optic transducer, may operate at high speeds with reduced jitter.

An antenna is disclosed. The antenna has a first element including an unbalanced antenna with a feed point, and a second element. The second element has a spaced relationship with the first element, and includes a balanced antenna arranged to be electromagnetically coupled to the first element. Embodiments of the invention exhibit relatively high Pattern Averaged Gain (PAG).

The invention discloses a low-profile dual-polarization dipole base station antenna loaded with an AMC reflecting plate. The antenna comprises a dual-polarization planar dipole antenna, four plastic support columns and the AMC reflecting plate. The dual-polarization planar dipole antenna comprises coupling microstrip lines, an upper dielectric plate, a radiating structure and coaxial lines from top to bottom in sequence; the AMC reflecting plate comprises a rectangular patch, a lower dielectric plate, an air dielectric, metal support columns and a metal plate which are periodically arranged from top to bottom in sequence, the coupling microstrip lines and the radiating structure are located on the upper side and the lower side of the upper dielectric plate in the same placing direction, and + / -45-degree dual-polarization is achieved in a coaxial line feeding mode. The dual-polarization planar dipole antenna is fixed to the AMC reflecting plate through the plastic support columns. Accordingly, the AMC reflecting plate is adopted for replacing an original metal reflecting plate, the antenna profile height is lowered to 0.132 lambda 2.2 GHz from 0.264 lambda 2.2 GHz, and meanwhile the advantages of being wide in frequency band, high in isolation, low in cross polarization, low in cost and the like are reserved. The application requirement of the current communication industry is met, and the low-profile dual-polarization dipole base station antenna conforms to the development trend of miniaturization of current base station antennae and has practical reference value.

An RFID tag which couples a radiating element or antenna to an integrated circuit without a physical conductor. The radiating element comprises a coil. The integrated circuit is affixed to the substrate having the antenna in such a way that the circuit chip coil is inductively coupled to the antenna coil. When the RFID tag is excited via the antenna, the inductive coupling causes both signaling and power to couple from the antenna to the circuit chip coil without a physical conductor connecting the antenna to the RFID tag integrated circuit.