1246results 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 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.

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.

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.

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.

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.