1247results about "Multi-frequency-changing modulation transference" patented technology

A system for powering a mobile device having an energy harvester which receives wireless energy and converts the energy into current includes a first portal in which wireless energy is transmitted for the energy harvester of the mobile device to receive and convert it into current when the device is in the first portal. The system comprises a second portal separate and apart from the first portal with a gap between the first portal and the second portal, the second portal in which wireless energy is transmitted for the energy harvester of the mobile device to receive and convert it into current after the device has passed through the first portal and the gap and is in the second portal. A method for powering a mobile device having an energy harvester which receives wireless energy and converts the energy into current is also disclosed.

A filter network having the capability of establishing multiple, tunable notch frequencies. A notch filter path is established for each notch frequency and includes a bandpass filter and inverter. An input RF signal covering a wide frequency range is applied to all the notch filter paths. Each notch filter path produces an output spectrum that is equal in magnitude and 180.degree. out of phase with respect to an undesired frequency spectrum. A combiner circuit combines the outputs of each notch filter path in parallel with the RF input signal to produce an RF output signal with all desired spectra unchanged and all undesired spectra attenuated.

A device, network and method wherein a standard wireless modem is coupled to wiring for carrying a wireless baseband signal that may be OFDM based, and may be directly generated by the wireless IF modem, or extracted from the modem RF signal. The wiring may be a building utility wiring, such as telephone, AC power or CATV wiring. The baseband signal is carried simultaneously with the utility service signal over the utility wiring using Frequency Division Multiplexing. The device may be enclosed with a data unit, a standalone dedicated enclosure, within an outlet or as a plug-in outlet adapter. Data units may couple the device by a wiring port such as standard data connector, or via wireless connection. The device may be locally powered or via a power signal carried over the wiring. This abstract is not intended to limit or construe the scope of the claims.

A passive harmonic switch mixer is shown that is immune to self mixing of the local oscillator greatly reducing leakage noise, pulling noise, and flicker noise when used in a direct conversion receiver or direct conversion transmitter circuit. The passive harmonic switch mixermixes an input signal received on an input port with an in-phase oscillator signal and a quadrature-phase oscillator signal and outputs an output signal on an output port. Because the quadrature-phase oscillator signal is the in-phase oscillator signal phase shifted by 90 °, the passive harmonic switch mixer operates with a local oscillator running at half the frequency of the carrier frequency of an RF signal. Additionally, because the passive harmonic switch mixer has no active components, the DC current passing through each switch device is reduced and the associated flicker noise of the mixer is also greatly reduced.

Frequency translation and applications of the same are described herein, including RF modem and wireless local area network (WLAN) applications. In embodiments, the WLAN invention includes an antenna, an LNA / PA module, a receiver, a transmitter, a control signal generator, a demodulation / modulation facilitation module, and a MAC interface. The WLAN receiver includes at least one universal frequency translation module that frequency down-converts a received EM signal. In embodiments, the UFT based receiver is configured in a multi-phase embodiment to reduce or eliminate re-radiation that is caused by DC offset. The WLAN transmitter includes at least one universal frequency translation module that frequency up-converts a baseband signal in preparation for transmission over the wireless LAN. In embodiments, the UFT based transmitter is configured in a differential and multi-phase embodiment to reduce carrier insertion and spectral growth.

A transceiver for use in wireless communications including a first antenna and first filter coupled thereto to transmit signals in a first frequency range and a second antenna and second filter means coupled thereto to receive signals in the first frequency range or a second different frequency, in dependence on a mode of operation of the transceiver. In a first mode of operation the transceiver is arranged to transmit signals in the first frequency range via the first antenna and to receive signals in the second frequency range via the second antenna, and in a second mode of operation, the transceiver is arranged to receive signals in the first frequency range via the second antenna. Alternatively, the second antenna and second filter may receive signals in a third frequency range and in the second mode of operation, the transceiver is arranged to receive signals in the third frequency range via the second antenna.

Agile frequency converter and method, IF-RF level exchange process, and notch filtering techniques. System noise and spurious levels generated by channel frequency conversion is reduced in applications requiring broadband combining of frequency converters to form multichannel composite signal. Converter employs two-stage frequency conversion process, with gain exchange system using variable pre-mixer gain and variable post-mixer attenuation to maintain constant RF output signal power level. For those few conversion frequencies where distortion component(s) cannot be filtered without degrading desired signal, IF-RF level exchange is optimized for meeting the carrier-to-distortion (C / D) ratio specifications at slight expense of noise level for that channel only, while still meeting aggregate combined carrier-to-noise (C / N) specification requirements. Optimal apportionment of level exchange for each channel depends on specific frequency rejection capability of spurious components and is matched to filtering capability and stored within non-volatile memory of a microcontroller used in the frequency converter.

The present invention provides a radio communication device, a transmitter and a receiver capable of handling a plurality of signal waves. A radio communication device has a millimeter-wave transmitter (15) and a millimeter-wave receiver (29). Millimeter-wave transmitter (15) includes a multiplexing circuit (1), a millimeter-wave up-converter (4) and an antenna (3), and the millimeter-receiver includes an antenna (31), a millimeter-wave down-converter (32) and an output processing circuit (45). The signal waves dedicated to the user are modulated by a modulation circuit (121 to 124) so as to be allocated between the ground broadcast waves and satellite broadcast waves. The frequencies are multiplexed in an intermediate frequency band, after that, the multiplexed frequencies are converted into a millimeter-wave band and the resultant is transmitted. On the reception side, the multiplexed waves are down-converted, separated to signal waves and demodulated.

An integrated circuit inductor includes a spiral pattern disposed upon a substrate. The track of the spiral is divided into multiple tracks to form a multi-track inductor. The individual tracks are disposed side by side and in different layers. Tracks that are aligned vertically are coupled by feed throughs, or vias. Multiple vias are used along the length of each of the multiple tracks. Tracks disposed in the same layer are joined together at their beginning, and at their termination. A patterned shield is fabricated from conductive fingers of n+ salicided material that is separated by non conducting polysilicon that fills the gaps between the fingers. The conductive fingers are coupled together in groups, which are in turn tied to a single point ground. In tying the groups together, a gap in the conducting path is provided to prevent ground loop currents. The shield is disposed between the multi-track inductor and the substrate.

A multi-channel RF receiver uses an image rejection mixer (e.g. double quadrature mixer) in the IF down conversion stage for image side band rejection (whereby use of an IF narrow band filter for image rejection may be omitted if desired) and comprises a simplified frequency synthesizer which generates both a “wandering” IF oscillator frequency and an RF oscillator frequency for the up / down conversion stages (being, for down conversion, from RF to IF and from IF to base band. The IF used for a particular RF carrier (channel) is selected so as to be both an integer (N) sub-harmonic of that RF carrier and within the operating frequency band of the image rejection mixer. Advantageously, the synthesizer comprises only one loop and one VCO, wherein the IF oscillator signal is produced from the RF oscillator signal by means of a frequency divider.

An integrated receiver with channel selection and image rejection substantially implemented on a single CMOS integrated circuit is described. A receiver front end provides programmable attenuation and a programmable gain low noise amplifier. Frequency conversion circuitry advantageously uses LC filters integrated onto the substrate in conjunction with image reject mixers to provide sufficient image frequency rejection. Filter tuning and inductor Q compensation over temperature are performed on chip. The filters utilize multi track spiral inductors. The filters are tuned using local oscillators to tune a substitute filter, and frequency scaling during filter component values to those of the filter being tuned. In conjunction with filtering, frequency planning provides additional image rejection. The advantageous choice of local oscillator signal generation methods on chip is by PLL out of band local oscillation and by direct synthesis for in band local oscillator. The VCOs in the PLLs are centered using a control circuit to center the tuning capacitance range. A differential crystal oscillator is advantageously used as a frequency reference. Differential signal transmission is advantageously used throughout the receiver.

A method and system of speech recognition presented by a back channel from multiple user sites within a network supporting cable television and / or video delivery is disclosed. The preferred embodiment of the invention comprises ans system and method of using a back channel containing a multiplicity of identified speech channels from a multiplicity of user sites presented to a speech processing system at a wireline node in a network that supports at least one of cable television delivery and video delivery. One embodiment of the invention comprises a method having the steps of receiving the back channel to create a received back channel; partitioning the received back channel into a multiplicity of received identified speech channels; processing the multiplicity of received identified speech channels to create a multiplicity of identified speech content; and responding to the identified speech content to create an identified speech content response that is unique, for each of the multiplicity of identified speech contents.

Methods and systems to implement and operate software-defined radios (SDRs). An SDR may be configured to perform a combination of fractional and integer frequency synthesis and direct digital synthesis under control of a digital signal processor, which may provide a set of relatively agile, flexible, low-noise, and low spurious, timing and frequency conversion signals, and which may be used to maintain a transmit path coherent with a receive path. Frequency synthesis may include dithering to provide additional precision. The SDR may include task-specific software-configurable systems to perform tasks in accordance with software-defined parameters or personalities. The SDR may include a hardware interface system to control hardware components, and a host interface system to provide an interface to the SDR with respect to a host system. The SDR may be configured for one or more of communications, navigation, radio science, and sensors.

A broadband integrated receiver for receiving input signals and outputting composite video and audio signals is disclosed. The receiver employs an up-conversion mixer and a down-conversion mixer in series to produce an intermediate signal. An intermediate filter between the mixers performs coarse channel selection. The down-conversion mixer may be an image rejection mixer to provide additional filtering.

A receiving circuit mainly available in a digital modulation type communication system having a plurality of channels, which is capable of reducing power in a receiving system, simplifying the circuit and reducing the power consumption. Upside and downside frequencies corresponding to a central value between channels are separately supplied from a local frequency signal generating circuit 4 to first and second frequency converting circuits 2, 3 so that two output signals are developed with respect to one of a desired wave, upside channel and downside channel. The desired wave present in common in the first and second frequency converting circuits 2, 3 is extracted in a common wave extracting circuit 5, and a frequency offset of omegao existing in the output of the common wave extracting circuit 5 is removed a frequency offset circuit 6 and further an unnecessary frequency component is filtered by a filter 8. In addition, the common wave extracting circuit 5 has transformers and, using its inductances, raises the difference between the common wave and the non-common wave within the circuit to more than two times that of a prior art.

A television tuner (920) is adapted for use in a television receiver (900) that receives a radio frequency (RF) signal from an input device (910) and outputs audio and video information from a selected channel in response thereto. The television tuner (920) includes a direct digital frequency synthesizer (206) and a mixer (220). The direct digital frequency synthesizer (206) has an output for providing a digital representation of a mixing signal. The mixer (220) has a signal input for receiving a television signal, a mixing input coupled to the output of said direct digital frequency synthesizer (206), and an output for providing an intermediate frequency (IF) television signal.

The invention provides a signal processing semiconductor integrated circuit of the direct conversion system, which includes a dummy amplifier having the same circuit configuration as a low noise amplifier being the first stage amplifier, in which the DC offset calibrations on the subsequent stage amplifiers are carried out during shifting into the reception mode in a state that the low noise amplifier is deactivated and the dummy amplifier is activated. Thereby, the invention achieves to suppress generation of the DC offsets resulting from the leakage noises of the local oscillator during shifting into the reception mode, and to enhance the reception sensitivity.

The invention relates to an integrated structure of a radio-frequency front end of a communications apparatus. The antenna of the communications apparatus is constructed on a printed circuit board. To this antenna board (310), on its ground plane side, a second circuit board (321) is attached by means of a rigid protective frame (410), which second circuit board includes the other parts of the radio-frequency front end. Between the parts impedance levels are used that are appropriate from the electrical operation perspective. All said parts together form an integrated component (400) to be located inside the housing of the communications apparatus. The advantage of the invention is that it requires a smaller number of components needed for matching between the RF parts, and makes possible a greater sensitivity of the receiver as well as a better transmitter efficiency than prior art structures.

A mixer circuit used in a radio receiver for mixing two frequencies and providing an intermediate frequency which is the difference of the two frequencies. Excellent image rejection is provided by decreasing an amplitude error and a phase error of an output IF signal in differential form.

A circuit for frequency translating a radio frequency signal comprises a plurality of mixer stages, each stage associated with a particular range of frequencies of a radio frequency signal. The circuit further comprises a switching circuit that communicates the radio frequency signal to a selected one of the plurality of mixer stages in response to a control signal. The selected mixer stage comprises a phase generation circuit that generates a plurality of phase signals, and at least one mixer that combines the radio frequency signal with one of the plurality of phase signals to generate at least a portion of an intermediate frequency signal.

A data recovery subsystem for use in a receive system configured to receive a magnetic field signal, the magnetic field signal including a carrier component usable for locating an underground object and at least one modulation sideband. The data recovery subsystem includes a first mixer to mix a Radio Frequency (RF) signal with a first Local Oscillator (LO) signal to produce an Intermediate Frequency (IF) signal representative of the magnetic field signal. A Phase Locked Loop (PLL) phase-locks a second LO signal to an IF carrier component of the IF signal. A second mixer synchronously mixes the IF signal with the second LO signal to produce a baseband signal including a demodulated sideband.

In a method of calibrating a quadrature transmitter, a first calibration signal is injected into an in-phase transmit branch of the quadrature transmitter, and a second calibration signal is injected into a quadrature transmit branch of the quadrature transmitter. The first and second calibration signals are injected before performing up-conversion in the transmitter and are produced by first and second digital signals. A detector detects an up-converted signal. The detected up-converted signal is digitized. The in-phase and quadrature transmit branches are calibrated by alternately determining the first and second calibration signals while at least varying respective most significant bits of the first and second digital signals, upon said varying the at least most significant bits keeping calibration bit values that correspond to minimum values of the digitized detected up-converted signal.

An integrated VCO having an improved tuning range over process and temperature variations. There is therefore provided in a present embodiment of the invention an integrated VCO. The VCO comprises, a substrate, a VCO tuning control circuit responsive to a VCO state variable that is disposed upon the substrate, and a VCO disposed upon the substrate, having a tuning control voltage input falling within a VCO tuning range for adjusting a VCO frequency output, and having its tuning range adjusted by the tuning control circuit in response to the VCO state variable.

A quadrature tranceiver has a transmitter, a receiver, and a common local oscillator. With the transmitter switched off and the receiver switched on, a DC-error in the receiver is nulled in servo loops in in-phase and a quadrature receiver paths. After settling, the servo loops provide output values that are freed of the DC-error. DC-nulling output values are then sampled and stored. After sampling, the servo loops are opened. Thereafter, the transmitter is switched on while inputting a fixed signal to the transmitter, and DC-signals injected into in-phase and quadrature paths of the transmitter are adjusted until the opened servo loops provide the same output signal as obtained at the end of the DC-nulling. Corresponding values of the injected DC-signals are then stored as transmitter calibration values.

An integrated receiver with channel selection and image rejection substantially implemented on a single CMOS integrated circuit is described. A receiver front end provides programable attenuation and a programable gain low noise amplifier. Frequency conversion circuitry advantageously uses LC filters integrated onto the substrate in conjunction with image reject mixers to provide sufficient image frequency rejection. Filter tuning and inductor Q compensation over temperature are performed on chip. The filters utilize multi track spiral inductors with shields to increase circuit Q. The filters are tuned using local oscillators to tune a substitute filter, and frequency scaling during filter component values to those of the filter being tuned. In conjunction with filtering, frequency planning provides additional image rejection. The advantageous choice of local oscillator signal generation methods on chip is by PLL out of band local oscillation and by direct synthesis for in band local oscillator. The VCOs in the PLLs are centered using a control circuit to center the tuning capacitance range. A differential crystal oscillator is advantageously used as a frequency reference. Differential signal transmission is advantageously used throughout the receiver. ESD protection is provided by a pad ring and ESD clamping structure that maintains signal integrity. Also provided are shunts at each pin to discharge ESD build up. The shunts utilize a gate boosting structure to provide sufficient small signal RF performance, and minimal parasitic loading.

In radiocommunication apparatus, two downconverters (41, 42) for use in reception system each heterodyne their respective received RF signal to an intermediate frequency. One of the downconverters employs a local signal generated by a synthesizer (19), and the other employs a signal obtained by dividing the frequency of the local signal by a factor of N. Two upconverters (161, 162) for use in transmission system each convert their respective input transmit signal to a transmit RF signal. One of the upconverters employs a local signal generated by the synthesizer (19) and the other employs a signal obtained by dividing the frequency of the local signal by a factor of N.

In a system for measuring a time difference of arrival of signals for positioning, an accurate time difference is measured by a receiver which is reduced in power consumption, size, and cost. The system comprises a node (under measurement) for transmitting a positioning signal, a reference station for transmitting a reference signal, and a plurality of access points for receiving the positioning signal and reference signal, and a server connected to the plurality of access points through a network. Each of the plurality of access points measures a time difference between the reception of the positioning signal and the reception of the reference signal, and a frequency deviation from the reference station, using a clock signal and a signal for shifting the clock signal, and the server calculates the position of the node based on the measured time difference and frequency deviation.

A digital IF demodulator receives and demodulates an analog IF input signal to produce a digital audio signal and a digital video signal. The digital IF demodulator includes an A / D converter, a first digital complex mixer, a second digital complex mixer, and various digital filters. The first digital complex mixer receives the output of the A / D converter and down-converts the output of the A / D converter to baseband. Additionally, the picture carrier is recovered from the output of the first digital complex mixer, and fed back to a direct digital synthesizer to control the tuning accuracy of the first digital complex mixer. More specifically, a feedback loop is formed to so that the picture carrier is down-converted to DC so as to control the tuning accuracy of the first digital complex mixer. The complex output of the first complex mixer is further processed using Nyquist filtering and other filtering to recover the digital video signal. The digital audio signal is recovered by further processing the output of the first digital complex mixer. With the picture carrier located at DC, the audio signal is shifted off DC by approximately 4.5 Mhz. A second complex mixer down-converts the output of the first digital complex mixer so that the audio signal at 4.5 MHz is down-converted to baseband. After filtering and demodulation, the digital audio signal is recovered.

Device for downward mixing an input signal into an output signal includes means for generating a first receive signal and a second receive signal on a first intermediate frequency, a converter means for analog / digital converting the first and the second receive signals on the first intermediate frequency, a phase detection means for detecting a phase difference between a digital representation of the first receive signal and the second receive signal, a first mixer means and a second mixer means for converting the respective digital representations onto a second intermediate frequency, a mixer control means and a summation means, wherein the phase detection means is implemented in order to control means for generating and / or mixer control means so that the output signals of the first and the second mixer means are in a predetermined phase relation to each other, so that an image frequency rejection occurs after a summation. By this it is achieved that the device for downward mixing is basically integrable and that an efficient image frequency rejection is obtained.

A method for exchanging data with an integrated circuit includes antenna connection terminals. The method includes not connecting the antenna connection terminals of the integrated circuit to an antenna, applying an alternating emulation signal at least to a first antenna connection terminal of the integrated circuit, by way of a wire link, in order to emulate the presence of an antenna signal on the first antenna connection terminal, sending data to the integrated circuit by injecting them in the emulation signal, and receiving data sent by the integrated circuit by taking them from the emulation signal.