372 results about "Rf filters" patented technology

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.

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.

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.

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.

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.

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 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.

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 Z_L material and a relatively high acoustic impedance Z_H 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.