58624results about How to "Reduce loss" patented technology

An apparatus and method for phototherapy are described in which laser light or other radiation is projected from within a catheter, through a balloon member, and toward the surface of tissue. The light reflected from body fluids or the tissue surface is captured by a collecting device located within the catheter, e.g., within the balloon member, and the intensity of the reflected light is ascertained. The apparatus and method provides for accurately positioning the apparatus against the tissue treatment site.

An electrosurgical system and method for transmitting, monitoring, and controlling electrosurgical energy and tissue parameter quality at the tissue site. The electrosurgical system includes a generator adapted to generate electrosurgical energy for treating tissue. The generator includes one or more active output terminals which supply energy to the tissue. The active output terminals are operatively connected to one or more active leads. The generator also includes one or more return output terminal which returns energy from the tissue. The return output terminals are operatively connected to at least one return lead. The system also includes an electrosurgical instrument operatively connected to the one or more active leads and one or more return electrodes operatively connected to one or more return leads. The system further includes an electrosurgical cable including one or more active leads and one or more return leads. The one or more active leads and one or more return leads are wound in a double helix fashion such that the electrical field along the cable is mitigated along the length thereof.

Systems for THz transmission using new types of THz waveguides with low loss, negligible group velocity dispersion and structural simplicity are described herein. The THz system incorporates the use of a waveguide with two or more substantially parallel conductive elements which may enable many new THz sensing applications. It is now possible to direct the THz pulse inside of containers or around corners, where line-of-sight optics are not practical. Moreover, the systems allow use of either radially polarized or linearly polarized THz antennas. The disclosed systems are compatible with existing terahertz generation and detection techniques.

It is an object of the invention to provide a connection structure for connecting the dielectric strip of an NRD guide with a metal waveguide, in which the conversion loss (connection loss) for high-frequency signals is reduced, and in which the NRD guide as well as the millimeter wave integrated circuit in which the NRD guide is incorporated can be made smaller. A non-radiative dielectric waveguide is made by arranging a dielectric strip for propagating high-frequency signals between parallel planar conductors arranged at a spacing of not more than half the wavelength of a high-frequency signal, a conductive member being arranged at an end face of a terminal end of the dielectric strip. An aperture is formed in at least one of the parallel planar conductors at a location where the electrical field of an LSM mode stationary wave propagating along the dielectric strip becomes largest. An open terminal end of a metal waveguide is connected to this aperture.

Systems and methods for employing switched phase shifters and a feed network to provide a low cost multiple beam antenna system for wireless communications. The present systems and methods may also facilitate multi-band communications and employ multi-diversity. The present systems and methods allow communication systems to achieve enhanced performance for communication or other services such as location tracking. The present systems and methods may employ switched phase shifters, multiple diversity antennas and / or a feed network having a multi-layer construction to provide an antenna system with low losses, low external component count and / or which is thin and compact.

A chip integrated waveguide feeding print antenna is composed by a chip with its two metal sides being transfixed with metal through holes in array. The two metal sides are in axial symmetry. There is an intergrading section to one side of the waveguide centerline on two surface of the chip linking with transmission line. To the outer end of the intergrading section links a vibrator antenna. To the opposite side of the intergrading section on the waveguide links a micro-strip intergrading commutator linking with micro-strip transmission line.

A communication device includes a case, a high frequency coupler that is disposed inwards from the surface of the case so as to be spaced apart from the surface and transmits and receives a signal of an induction electric field, and a surface wave transmission path that is disposed between the radiation surface of the induction electric field of the high frequency coupler and the surface of the case.

In this invention, a fiber optic rotary joint and applications of such to retractable fiber optic cables is described. The fiber optic rotary joint consists of a spiral arrangement of a spring and optical fiber pair placed between rotating inner and outer diameters. The fiber optic rotary joint provides a finite number of turns of a fiber optic cable about a primary axis. These turns can be used, for example, with a rotating spool to provide a continuous retractable and extendable cable.

The present invention relates to a source-antenna for transmitting / receiving electromagnetic waves comprising an array of n radiating elements (113, 114) operating in a first frequency band, means (20) with longitudinal radiation operating in a second frequency band, the array and the means with longitudinal radiation having a substantially common phase centre, the n radiating elements being arranged symmetrically about the longitudinal-radiation means, and each element (113, 114) of the array consisting of a radiating element of the travelling wave type.

Tunable dielectric materials including an electronically tunable dielectric ceramic and a low loss glass additive are disclosed. The tunable dielectric may comprise a ferroelectric perskovite material such as barium strontium titanate. The glass additive may comprise boron, barium, calcium, lithium, manganese, silicon, zinc and / or aluminum-containing glasses having dielectric losses of less than 0.003 at 2 GHz. The materials may further include other additives such as non-tunable metal oxides and silicates. The low loss glass additive enables the materials to be sintered at relatively low temperatures while providing improved properties such as low microwave losses and high breakdown strengths.

A method and apparatus use a photonic-crystal fiber having a very large core while maintaining a single transverse mode. In some fiber lasers and amplifiers having large cores problems exist related to energy being generated at multiple-modes (i.e., polygamy), and of mode hopping (i.e., promiscuity) due to limited control of energy levels and fluctuations. The problems of multiple-modes and mode hopping result from the use of large-diameter waveguides, and are addressed by the invention. This is especially true in lasers using large amounts of energy (i.e., lasers in the one-megawatt or more range). By using multiple small waveguides in parallel, large amounts of energy can be passed through a laser, but with better control such that the aforementioned problems can be reduced. An additional advantage is that the polarization of the light can be maintained better than by using a single fiber core.

Provided is an antenna device, which has excellent cost performance and a small antenna loss and can eliminate radio wave interference, for wireless communication employing an omni-cell system, wherein a plurality of data associated with each other are transmitted at the same time. The antenna device has a plurality of sector antennas (11) which are disposed such that the maximum radiation directions wherein the radiation intensity of the radio waves is at maximum are arranged in the radial state, and the sector antennas (11) transmit at the same time a plurality of wireless signals associated with each other.

A system for coupling teraherz (THz) radiation to a coaxial waveguide comprises an antenna that generates THz radiation having a mode that matches the mode of the waveguide. The antenna may comprise a pair of concentric electrodes, at least one of which may be affixed to or formed by one end of the waveguide. The radiation may have wavelengths between approximately 30 μm and 3 mm. The waveguide may comprise an inner core and an outer wall defining an annular region. A terahertz sensor system may comprise a terahertz antenna comprising first and second concentric electrodes, means for generating a field across the trodes and means for triggering the emission of terahertz radiation, a first waveguide having first and second ends, said first end being coupled to said antenna so as to receive at least a portion of said terahertz radiation, and a sensor for detecting said terahertz radiation.

The invention relates to a DC-DC power supply conversion device, in particular to a zero-voltage switch (ZVS) flyback-type DC-DC power supply conversion device with efficient conversion, efficient light-load conversion and low standby power consumption. An auxiliary switch and an absorption capacitor are additionally arranged on the flyback circuit; the auxiliary switch and the absorption capacitor are connected in series so as to form an auxiliary branch circuit; the auxiliary branch circuit can be connected in parallel to the two ends of the primary winding of a transformer or alternatively connected in parallel to the two ends of a primary-side switch; and the auxiliary switch is conductive for a determined period of time before the primary-side switch is conductive. Compared with the prior art, the energy of the circuit leakage inductor can be absorbed and transferred to the output terminal and a soft switch for realizing the primary-side switch, so that the invention can greatly improve the circuit efficiency; the parasitic oscillation caused by the leakage inductor can be suppressed, so that the EMI (electromagnetic interference) characteristics of the circuit can be improved; and the circuit can be controlled more easily, thereby improving the light-load circuit efficiency and reducing the idle-load energy loss.

An accumulation-mode MISFET comprises: a high-resistance SiC layer 102 epitaxially grown on a SiC substrate 101; a well region 103; an accumulation channel layer 104 having a multiple δ-doped layer formed on the surface region of the well region 103; a contact region 105; a gate insulating film 108; and a gate electrode 110. The accumulation channel layer 104 has a structure in which undoped layers 104b and δ-doped layers 104a allowing spreading movement of carriers to the undoped layers 104b under a quantum effect are alternately stacked. A source electrode 111 is provided which enters into the accumulation channel layer 104 and the contact region 105 to come into direct contact with the contact region 105. It becomes unnecessary that a source region is formed by ion implantation, leading to reduction in fabrication cost.

An array antenna device includes a plurality of slot array antennas which are arranged and each of which includes a plurality of slot antennas and a radiation surface, which is formed to be conformal, and a plurality of waveguides each of which supplies respective power to each of the slot array antennas. After bodies of the waveguides are formed by a resin molding method, surface treatment is performed with respect to inner surfaces of the waveguides with plating.

A chip integrated waveguide feeding print antenna is composed by a chip with its two metal sides being transfixed with metal through holes in array. The two metal sides are in axial symmetry. There is an intergrading section to one side of the waveguide centerline on two surface of the chip linking with transmission line. To the outer end of the intergrading section links a vibrator antenna. To the opposite side of the intergrading section on the waveguide links a micro-strip intergrading commutator linking with micro-strip transmission line.

A vertically packaged cellular power converter solves the problems associated with conventional designs and paves the way for a cellular circuit architecture with ultra-low interconnect resistance and inductance. The vertical packaging results in a power flow in the vertical direction (from the bottom to the top) with very short internal interconnects, thereby minimizing the associated conduction losses and permitting high conversion efficiency at high currents. The cellular architecture is ideally suited for generating multiple supply voltages.

A low-cost PFC converter capable of detecting an inductor current including a DC component and performing appropriate correction of a power factor with low loss includes a diode bridge that rectifies an AC voltage input from an AC input power supply Vac, a series circuit including an inductor and a switching element, a rectifying and smoothing circuit that is connected in parallel to the switching element and that includes a diode and a smoothing capacitor, and a digital signal processing circuit that performs on / off control on the switching element so that an input current input from the AC input power supply Vac has a similar waveform with respect to an AC voltage. A current flowing through the inductor during an off period of the switching element is detected using a current detecting resistor, and a decreased voltage of the current detecting resistor is sampled at the middle of the off period of the switching element, thereby detecting an average value of the input current.