381 results about "Rf filters" patented technology

The present invention relates generally to radio communication devices. More particularly, the present invention relates to a programmable radio frequency (RF) sub-system and wireless communications devices using such an integrated antenna / filter sub-system. In one embodiment, the programmable RF front end subassembly includes two antennas, RF filter sections that are integral to each antenna, and a programmable logic device as an antenna control unit. Each antenna consists of a planar inverted "F" antenna (PIFA) that is tuned to operate over a range of frequencies using voltage variable capacitors or RF switches that connect various capacitive loads in order to achieve the desired resonant frequencies. The wireless communication device further includes a control circuit coupled to the antenna to provide the control signals.

A system and method for using magnetic resonance imaging to increase the accuracy of electrophysiologic procedures is disclosed. The system in its preferred embodiment provides an invasive combined electrophysiology and imaging antenna catheter which includes an RF antenna for receiving magnetic resonance signals and diagnostic electrodes for receiving electrical potentials. The combined electrophysiology and imaging antenna catheter is used in combination with a magnetic resonance imaging scanner to guide and provide visualization during electrophysiologic diagnostic or therapeutic procedures. The invention is particularly applicable to catheter ablation, e.g., ablation of atrial fibrillation. In embodiments which are useful for catheter ablation, the combined electrophysiology and imaging antenna catheter may further include an ablation tip, and such embodiment may be used as an intracardiac device to both deliver energy to selected areas of tissue and visualize the resulting ablation lesions, thereby greatly simplifying production of continuous linear lesions. The invention further includes embodiments useful for guiding electrophysiologic diagnostic and therapeutic procedures other than ablation. Imaging of ablation lesions may be further enhanced by use of MR contrast agents. The antenna utilized in the combined electrophysiology and imaging catheter for receiving MR signals is preferably of the coaxial or “loopless” type. High-resolution images from the antenna may be combined with low-resolution images from surface coils of the MR scanner to produce a composite image. The invention further provides a system for eliminating the pickup of RF energy in which intracardiac wires are detuned by filtering so that they become very inefficient antennas. An RF filtering system is provided for suppressing the MR imaging signal while not attenuating the RF ablative current. Steering means may be provided for steering the invasive catheter under MR guidance. Other ablative methods can be used such as laser, ultrasound, and low temperatures.

A plasma processing chamber for processing a substrate to form electronic components thereon is disclosed. The plasma processing chamber includes a plasma-facing component having a plasma-facing surface oriented toward a plasma in the plasma processing chamber during processing of the substrate, the plasma-facing component being electrically isolated from a ground terminal. The plasma processing chamber further includes a grounding arrangement coupled to the plasma-facing component, the grounding arrangement including a first resistance circuit disposed in a first current path between the plasma-facing component and the ground terminal. The grounding arrangement further includes a RF filter arrangement disposed in at least one other current path between the plasma-facing component and the ground terminal, wherein a resistance value of the first resistance circuit is selected to substantially eliminate arcing between the plasma and the plasma-facing component during the processing of the substrate.

A smart radio incorporating Parascan® varactors embodied within an intelligent adaptive RF front end. More specifically, this is provided for by a smart radio incorporating Parascan® varactors embodied within an intelligent adaptive RF front end that comprises at least one tunable antenna; at least one antenna null steering facility associated with said at least on tunable antenna; at least one tunable duplexer receiving the output from and providing input to said at least one antenna null steering facility; a first tunable RF filter receiving the output from said at least one tunable duplexer and providing the input to an analog to digital converter, said analog to digital converter providing the input to a digital signal processor, the output of which is input for a digital to analog converter; a second tunable RF filter receiving the analog output of said digital to analog converter and providing an input to said at least one tunable duplexer.

A filtered button DC interconnect employing a compressible conductor such as a finely wound wire mesh imbedded within a series of dielectric and ferrite cylinders. The compressible conductor is captivated within the series of dielectric and ferrite cylinders to ensure proper contact with mating surfaces of interconnected circuits. The interconnect serves as an RF filter by providing rejection of RF and microwave frequencies between the interconnected circuits.

Methods and apparatus for implementing a wireless communication transceiver having receive path performance diversity. The transceiver implements a plurality of signal paths that can be configured as diversity receive paths. Each of the plurality of signal paths includes a distinct RF filter. Each RF filter can be configured to provide a distinct jammer rejection profile. Each receive path also includes a jammer detector, that can be a multiple level jammer detector. Each jammer detector operates to control a level of processing gain applied to the signals in its receive path. The multiple gain scaled receive signals can be combined in a coherent combiner before being routed for further processing.PATENT

An RF circuit device using modified lattice, lattice, and ladder circuit topologies. The devices can include four resonator devices and four shunt resonator devices. In the ladder topology, the resonator devices are connected in series from an input port to an output port while shunt resonator devices are coupled the nodes between the resonator devices. In the lattice topology, a top and a bottom serial configurations each includes a pair of resonator devices that are coupled to differential input and output ports. A pair of shunt resonators is cross-coupled between each pair of a top serial configuration resonator and a bottom serial configuration resonator. The modified lattice topology adds baluns or inductor devices between top and bottom nodes of the top and bottom serial configurations of the lattice configuration. These topologies may be applied using single crystal or polycrystalline bulk acoustic wave (BAW) resonators.

A highly integrated terrestrial and cable tuner for receiving digital and analog television signals is disclosed. It achieves high performances in sensitivity, image rejection, dynamic range, channel selectivity and power consumption. A major-images rejection converter disclosed rejects third- and fifth-order images. Thus it significantly relaxes RF filter design in a tuner of a single-stage or a first-stage zero-IF / low-IF downconversion architecture. Different architectures and frequency planning are disclosed in accordance with specifications of TV standards to improve the overall performance of the tuner with a different or configurable IF output. The tuner is integrated by using standard processes, with minimal off-chip components excluding SAW and LC filters. Small tuner modules cost less than discrete (can) tuners. They can be used in digital / analog TV sets and portable and handheld TV devices and for mobile-phone TV reception.

An RFID tag for use with an MRI machine has an integrated circuit and structure for protecting it from damage when exposed to an intense MRI RF transmitter field. The structure for protecting the integrated circuit may include a controllable low impedance device coupled across the integrated circuit, a controllable high impedance device coupled in series with the integrated circuit, and / or frequency selective RF filter.

An RF filter, e.g. RF cavity filter for adjusting coupling amount or transmission zero is disclosed. The RF filter includes a housing member in which cavities are defined by walls, resonators located in the cavities, a cover combined with an upper surface of the housing member, a first tuning element inserted into a first cavity of the cavities through the cover, and a second tuning element inserted into a second cavity of the cavities through the cover. Here, the first tuning element and the second tuning element are connected electrically.

The present invention is an RF filter that translates impedances of an IF circuit to create a filter with an RF center frequency having the high Q roll-off characteristics of an IF filter. The RF filter is self-aligned with the frequency of an RF local oscillator. The RF filter has an impedance divider, which is formed by coupling an RF impedance circuit to a translated IF impedance circuit. The translated IF impedance circuit includes an RF passive mixer and an IF impedance circuit. The mixer translates the impedance of the IF impedance circuit by mixing an RF input signal with an RF local oscillator signal, which determines the RF center frequency. Filtered RF signals may be provided by the impedance divider. Filtered IF signals may be provided by the IF impedance circuit. To effectively translate and preserve the IF impedance characteristics, the IF impedance circuit presents a high impedance at harmonics of the RF local oscillator signal.

Methods and apparatus for implementing a wireless communication transceiver having receive path performance diversity. The transceiver implements a plurality of signal paths that can be configured as space diversity receive paths. Each of the plurality of signal paths includes a distinct RF filter. Each RF filter can be configured to provide a distinct frequency response, and in particular, a distinct jammer rejection profile. One of the RF filters can be configured to provide substantially no in-band jammer rejection. Each additional distinct RF filter can be configured to reject at least one distinct in-band jammer frequency or band of frequencies. A diversity receiver coherently combines the path performance diverse signals from each filter output. A transmitter can time division duplex transmit communications over at least a subset of the signal paths and their associated RF filters.

Disclosed are apparatus and methods related to ground paths implemented with surface mount devices to facilitate shielding of radio-frequency (RF) modules. In some embodiments, a module can include a packaging substrate configured to receive a plurality of components. The module can further include an RF component mounted on the packaging substrate and configured to facilitate processing of an RF signal. The module can further include an RF shield disposed relative to the RF component, with the RF shield being configured to provide shielding for the RF component. The RF shield can include at least one shielding-component configured to provide one or more electrical paths between a conductive layer on an upper surface of the module and a ground plane of the packaging substrate. The shielding-component can include a surface-mount device such as an RF filter implemented as a chip size surface acoustic wave (SAW) device (CSSD).

A software defined radio (SDR) for communicating a plurality of radio signals over a wireless communications network. The radio comprising: a programmable system having a plurality of digital processors for processing digital data representing a digital form of the plurality of radio signals, the programmable system also for configuring operation of radio hardware for processing of the radio signals themselves; a configurable intermediate frequency (IF) interface for processing the plurality of radio signals for subsequent processing as the digital data communicated to the programmable system and the digital data received from the programmable system, the IF interface having a first connector for releasably connecting a modular IF filter component for use in the processing of said plurality of radio signals, the modular IF filter component being part of the radio hardware for selecting an IF center frequency and channel bandwidth of the SDR; and an RF platform coupled to the IF interface and configured for having with at least one radio portion, each radio portion for receiving and transmitting the radio signal over the communications network on behalf of the IF interface, said each radio portion having a second connector for releasably connecting a modular RF filter component for use in the processing of said plurality of radio signals, the modular RF filter component being part of the radio hardware for selecting an RF sub-band and RF center frequency of said each radio module; wherein the programmable system is adapted to configure operation of the SDR through recognition of the corresponding connected modular RF and IF filters.

There is disclosed a hybrid circuit in which a circuit formed by TFTs is integrated with an RF filter. The TFTs are fabricated on a quartz substrate. A ceramic filter forming the RF filter is fabricated on another substrate. Terminals extend through the quartz substrate. The TFTs are connected with the ceramic filter via the terminals. Thus, an RF module is constructed.

Implementations of the present disclosure generally relate to methods and apparatus for generating and controlling plasma, for example RF filters, used with plasma chambers. In one implementation, a plasma processing apparatus is provided. The plasma processing apparatus comprises a chamber body, a powered gas distribution manifold enclosing a processing volume and a radio frequency (RF) filter. A pedestal having a substrate-supporting surface is disposed in the processing volume. A heating assembly comprising one or more heating elements is disposed within the pedestal for controlling a temperature profile of the substrate-supporting surface. A tuning assembly comprising a tuning electrode is disposed within the pedestal between the one or more heating elements and the substrate-supporting surface. The RF filter comprises an air core inductor, wherein at least one of the heating elements, the tuning electrode, and the gas distribution manifold is electrically coupled to the RF filter.

A filter-balun combination for filtering an RF input signal and balancing output RF signals is provided. The filter-balun combination is formed in a multi-layer planar substrate having multiple dielectric layers and multiple planar device layers having conducting material. The filter section includes first and second symmetrical inductors formed in the substrate. The inductors provide filtering for an input signal. The balun section includes a balun central transmission line connected to an output of the filter, and two output structures for providing the output from the filter-balun combination. The central transmission line follows a path through the substrate that includes first and second coil areas. The input line is sandwiched between upper and lower transmission lines in the first and second coil areas. The output of the filter-balun combination is a filtered, balanced signal at each of the two balun output structures.

In a plasma processing chamber, a method for processing a substrate is provided. The method includes supporting the substrate in the plasma processing chamber configured with an upper electrode (UE) and a lower electrode (LE), configuring at least one radio frequency power source to ignite plasma between the UE and the LE, and providing a conductive coupling ring, the conductive coupling ring is coupled to the LE to provide a conductive path. The method further includes providing a plasma-facing-substrate-periphery (PFSP) ring, the PFSP ring being disposed above the conductive coupling ring. The method yet further includes coupling the PFSP ring to at least one of a direct current (DC) ground through an RF filter, the DC ground through the RF filter and a variable resistor, a positive DC power source through the RF filter, and a negative DC power source through the RF filter to control plasma processing parameters.

Polarization-preserving microwave RF filters having multiple resonators that are each operable for different Q factors for setting overall bandwidth. A coaxial dual-polarized waveguide filter may include a cable having a hollow circular body with ends formed by copper plates that each includes at least one iris. The irises may control the energy transfer into and out of the cavity and therefore set the Q factor for the body. The shape of the internal diameter of the body and the irises may provide for reception and propagation of differently polarized signals. Multiple segments may be cascaded in series to effect higher order filtering. Also described are methods of transmitting signals using these filters.

A system for processing a signal comprises a Radio Frequency (RF) signal tuner, one or more filters in a signal path of the RF tuner each based on Inductive / Capacitive (LC) circuitry, a variation unit operable to measure a variation of the LC circuitry, and a frequency control unit adapted to adjust the one or more filters based on the LC variation during operation of the tuner.

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 filtered button DC interconnect employing a compressible conductor such as a finely wound wire mesh imbedded within a series of dielectric and ferrite cylinders. The compressible conductor is captivated within the series of dielectric and ferrite cylinders to ensure proper contact with mating surfaces of interconnected circuits. The interconnect serves as an RF filter by providing rejection of RF and microwave frequencies between the interconnected circuits.

A highly integrated terrestrial and cable tuner for receiving digital television signals is disclosed. It achieves high performances in sensitivity, image rejection, dynamic range, channel selectivity and power consumption. The tuner first converts an RF input signal into a high-frequency first intermediate frequency (IF) using a single quadrature image rejection converter. Consequently, it significantly relaxes RF filter design. A second converter downconverts the first IF signal into either a baseband signal or a low-IF signal. The tuner can interface with a demodulator having the baseband and / or low-IF input interface. The tuner is integrated by using standard processes, with minimal off-chip components excluding SAW and LC filters. Small tuner modules cost less than discrete (can) tuners. They can be used in digital TV sets and portable / handheld TV devices.

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.

Several MEMS-based methods and architectures which utilize vibrating micromechanical resonators in circuits to implement filtering, mixing, frequency reference and amplifying functions are provided. A method and subsystem are provided for processing RF signals utilizing a plurality of vibrating micromechanical devices typically in the form of an IF mixer-filter and an RF channel selector or an image-reject RF filter. One of the primary benefits of the use of such architectures is a savings in power consumption by trading power for high selectivity (i.e., high Q). Also, such methods and circuits can eliminate the need for a low noise amplifier in a receiver or transceiver subsystem. Consequently, the present invention relies on the use of a large number of micromechanical links in SSI networks to implement signal processing functions with basically zero DC power consumption.

A microelectromechanical (MEM) resonator is disclosed which has a linear or ring-shaped acoustic resonator suspended above a substrate by an acoustic reflector. The acoustic resonator can be formed with a piezoelectric material (e.g. aluminum nitride, zinc oxide or PZT), or using an electrostatically-actuated material. The acoustic reflector (also termed an acoustic mirror) uses alternating sections of a relatively low acoustic impedance ZL material and a relatively high acoustic impedance ZH material to isolate the acoustic resonator from the substrate. The MEM resonator, which can be formed on a silicon substrate with conventional CMOS circuitry, has applications for forming oscillators, rf filters, and acoustic sensors.