138 results about "RF modulator" patented technology

The present invention is directed to a non-intrusive data transmission network for use in a healthcare facility and method for implementing such network. Each individual patient's room is equipped with a set-top control device, a separate camera, microphone, control module camera control device. The SCD allows for a non-intrusive installation within a minimum amount of time. By utilizing the existing cable television infrastructure, the device creates a high-speed data network throughout the facility. The interface between the SCD and the CCD is accomplished through a standard interface for universally connecting auxiliary devices, such as USB, for enabling expandable, hot-pluggable Plug and Play serial device interfaces. These ports allow external devices such as the camera, microphone, infrared keyboard and privacy control unit to communicate with the SCD. Additional USB ports on the SCD allow for other devices to be connected to the network at a future time. Such devices include those for instrument monitoring, doctor information access or pharmaceutical prescription ordering. Visual information such as e-mail, web browsing, video and audio communications via web camera applications from family members, friends or other parties may be viewed by the patient from the in-room TV set by way of the internal RF modulator (and connecting to the Internet via the patient Internet server). The SCD switches from the standard cable TV channels to the SCD by way of an internal switch controlled by the patient from an infrared control. This control also enables or disables the camera to allow for privacy at times when such privacy is required from external Internet access. The system is configurable to offer this privacy to be layered from specific Internet or external users to the nurses, doctors or security department as the hospital desires.

An RF transmitter uses two digital-to-RF conversion modules to convert digital baseband signals into RF signals. In Cartesian mode, baseband signals are conveyed to the conversion modules for RF conversion. In polar mode, baseband signals are converted into amplitude and phase data parts. Phase data part is converted into I and Q data parts to be converted by the conversion modules into RF signals, which are modulated in a power amplifier by amplitude data part through the power supply of the power amplifier. Each digital-to-RF module uses parallel unit cells to perform D / A conversion function and upconversion function by an IF signal. Each unit cell, adapted to receive a control voltage indicative of a data signal value, is a mixer cell type converter having a differential data switch section connected in series to a differential LO-switch pair. LO-switch is further connected in series to a current source.

A presence detection system comprising, among other things, a radio transmitter and receiver is described herein. The transmitter includes a motion detection circuit, a microprocessor, and a radio frequency modulator. The motion detection circuit is configured to direct a motion detected signal to the microprocessor upon the transmitter being moved in a predetermined manner. The microprocessor is configured to generate an encoded message that includes a preamble denoting a beginning of the encoded message, an identification code denoting a type of transmitter, and a check message (such as a checksum) containing information about content of the encoded message. Finally, the radio frequency modulator is configured to modulate the encoded message at a transmitting frequency.

Distributed and highly software reconfigurable CMTS (CMRTS) device, based on MAC and PHY units with FPGA and DSP components, for a HFC CATV network. The various CATV RF modulators, such as QAM modulators, may be divided between QAM modulators located at the cable plant, and remote QAM modulators ideally located at the fiber nodes. A basic set of CATV QAM data waveforms may optionally be transmitted to the nodes using a first fiber, and a second set of IP / on-demand data may be transmitted to the nodes using an alternate fiber or alternate fiber frequency, and optionally using other protocols such as Ethernet protocols. The nodes will extract the data specific to each neighborhood and inject this data into unused QAM channels, thus achieving improved data transmission rates through finer granularity. A computerized “virtual shelf” control system for managing and reconfiguring the FPGA and DSP based CMTRS units is also disclosed.

A method and system for generating a frequency hopping electromagnetic signal based on a baseband data signal includes a frequency hopping pre-compensator. The frequency hopping pre-compensator determines a frequency hopping pre-compensation signal based on a desired frequency hopping sequence. The frequency hopping pre-compensation signal is combined with the baseband data signal to generate a pre-compensated baseband signal. An RF modulator modulates an RF carrier in accordance with the pre-compensated baseband signal to generate a modulated, frequency hopping RF carrier signal. An amplifier may then amplify the RF carrier signal as desired.

A radio frequency (RF) transmitter uses two digital-to-RF conversion modules to convert digital baseband signals into RF signals. In cartesian mode, baseband signals are conveyed to the conversion modules for RF conversion. In polar mode, baseband signals are converted into amplitude and phase data parts. Phase data part is converted into I (inphase) and Q (quadrature) data parts to be converted into RF signals which are modulated in a power amplifier by amplitude data part through the power supply of the power amplifier. Each digital-to-RF module uses parallel unit cells to perform digital-to-analog (D / A) conversion and upconversion functions by an IF signal. Each unit cell, adapted to receive a control voltage indicative of a data signal value, is a mixer cell type converter having a differential data switch section connected in series to a differential LO (local oscillator)-switch pair. LO-switch is further connected in series to a current source.

Distributed and software reconfigurable remote CMTS (CMRTS) device, based on MAC and PHY units with FPGA and DSP components, for a HFC CATV network. The various CATV RF modulators, such as QAM modulators, may be located entirely at the fiber nodes if desired. Although a basic set of CATV QAM data waveforms may optionally be transmitted to the nodes using a first fiber, in a preferred embodiment, all data may be transmitted to the nodes using other protocols such as Ethernet protocols. The nodes will extract the data specific to each neighborhood and inject this data into the cable portion of the system as RF waveforms, such as RF QAM channels. A computerized “virtual shelf” control system for managing and reconfiguring the FPGA and DSP based CMTRS units, as well as a new type of edge router based all-digital virtual head end (virtual converged cable access platform) is also disclosed.

A transmitter of a base station includes a data serial-to-parallel converter, M modulators, M beam formers, and transmission antennas. The data serial-to-parallel converter converts transmission data into M sequences. Each modulator modulates the transmission data. Each beam former weights the modulation signal to form directional beams. The transmission antennas narrow the beams and transmit the modulation signals in parallel (MIMO transmission). In a mobile station, a receiver has reception antennas for receiving data transmitted in parallel and an MIMO demodulator for demodulating the data.

A Wireless Neural Data Acquisition System for increased power efficiency, compact size, robust signaling and reliable transmission is shown and described. In one embodiment, the system includes a headstage, an RF receiver, an analog-to-digital converter, a digital signal processor, and a communication interface. The headstage includes at least one input pre-amplifier high-pass filter and amplifier, a multiplexer (MUX), an RF Modulator comprising a voltage control oscillator (VCO), a transmitting antenna, and a power supply. The RF receiver includes at least one receiving antenna, at least one bandpass filter, at least one amplifier, at least one attenuator, and an FM Demodulator.

A phase lock loop RF modulator system including a phase lock loop circuit having a phase detector circuit responsive to an input reference signal and a feedback signal, an oscillator circuit responsive to the phase detector circuit for providing an output signal, a forward path from the phase detector circuit to the oscillator circuit, and a feedback path from the oscillator circuit to the phase detector circuit. The system also includes a first modulation port coupled to the feedback path, a second modulation port coupled to the forward path, and a gain mismatch detection circuit responsive to modulation data and a phase error between the reference signal and the feedback signal for providing an indicator output signal that represents the gain mismatch between the first modulation port and the second modulation port.

A processing device includes a plurality of modulators, the plurality of modulators performing modulation according to a first modulation scheme, a combiner configured to combine outputs from the plurality of modulators, and a signal processor configured to receive a bit stream and convert the bit stream into a plurality of input signals for the plurality of modulators such that the combiner generates a modulated output according to a second modulation scheme. The plurality of modulators may be low order modulators and a modulation schemes of the modulated output may include, for example, rotated quadrature phase shift keying (QPSK), pulse amplitude modulation (PAM), high order quadrature amplitude modulation (QAM), and multi-resolution high order quadrature amplitude modulation (M-QAM).

Distributed and highly software reconfigurable CMTS (CMRTS) device, based on MAC and PHY units with FPGA and DSP components, for a HFC CATV network. The various CATV RF modulators, such as QAM modulators, may be divided between QAM modulators located at the cable plant, and remote QAM modulators ideally located at the fiber nodes. A basic set of CATV QAM data waveforms may optionally be transmitted to the nodes using a first fiber, and a second set of IP / on-demand data may be transmitted to the nodes using an alternate fiber or alternate fiber frequency, and optionally using other protocols such as Ethernet protocols. The nodes will extract the data specific to each neighborhood and inject this data into unused QAM channels, thus achieving improved data transmission rates through finer granularity. A computerized “virtual shelf” control system for managing and reconfiguring the FPGA and DSP based CMTRS units is also disclosed.

A remote control unit for controlling a locomotive by transmitting signals to a remote receiver mounted onboard the locomotive is provided. The remote control unit includes an input for receiving a signal indicative of a command selected from a set of available commands. A signal transmitting unit transmits a signal indicative of the selected command repetitively to create a succession of signal transmission events. In a first example, each signal transmission event is spaced in time from a previous signal transmission event by a certain time interval having a duration conditioned at least in part on the basis of the selected command. In a second example, each signal transmission event includes a message portion and a header portion and the message portion of the signal has a length conditioned at least in part on the basis of the selected command. In a third example, each signal transmission event is characterized by a signal level conditioned at least in part on the basis of the selected command. The signal transmitting unit includes an RF modulator adapted for modulating data indicative of the selected command to generate a succession of modulated signals, each modulated signal corresponding to a respective signal transmission event in the succession of signal transmission events.

The invention discloses a rapid local oscillator leakage calibrating device facing an IQ modulator. A radio frequency signal source provides a local oscillator signal and a spectrum analyzer is used for measuring amplitude of the local oscillator signal output by an IQ modulator. During actual operation, the radio frequency signal output end of the a radio frequency signal source is connected to a local oscillator signal input end of the IQ modulator; and the spectrum analyzer is connected to the radio frequency signal output end of the IQ modulator. By controlling the IQ modulator, the output level of direct current bias compensation DAC of an internally arranged I path and a Q path are changed for five times, and direct current bias error compensation values of the I path and the Q path of the IQ modulator can be obtained via calculation, thereby further finishing calibration of local oscillator leakage of the IQ modulator.

A method and a highway addressable remote transducer (HART) soft modem device for modulating and demodulating one or more analog signals with HART messages are provided. A phase coherent frequency shift keying (FSK) modulator modulates and transmits the analog signals, and a phase coherent FSK demodulator receives and demodulates the analog signals. The FSK modulator outputs 1 or 0 for transmission. With oversampling and low pass filtering, digital modulation performed by the FSK modulator results in low jitter and a good signal to noise ratio. The FSK demodulator applies a fast energy detect algorithm and dynamically reduces or increases a clock speed of a central processing unit (CPU) of the HART soft modem device for reducing power consumption of the CPU. Furthermore, the HART soft modem device uses direct memory access and runs multiple instances of a HART soft modem integrated within a microcontroller to reduce an overall power consumption.

A radio frequency modulator based on direct frequency / phase modulation of output signal of a controllable oscillator (724) that is a part of a phase locked loop (PLL) provides a direct modulator that is able to operate over a wide frequency range with a flat frequency response. A modulation signal is digitally processed (721, 730) before injection to a high-pass path of a direct modulator. Applicability of digital signal processing is based on the fact that the modulation signal is a base band signal. Therefore, the modulation signal (702) occupies such a band in the frequency domain so that a sufficient ratio of a sampling rate to an upper edge frequency of the modulation signal can be achieved. Digital processing is used for compensating an effect of non-flat high-pass PLL transfer function and / or to perform pre-distortion of the input signal of a controlled oscillator to compensate an effect of non-linearity of a controlled oscillator.

This invention discloses a method for generating radio signals and wire baseband at the same time by a double-arm modulator and a single-wavelength light source in a radio-on-fiber(ROF) communicastion system and a system for transmitting two kinds of signals simultaneously on a same wavelength by fiber, which utilizes a dual-webbing modulation and a optical filter theory to generate dual-webbing signals and filter ROF mm waves and baseband data signals from down link to be provided to different users, and this invented system is not only used in single-channel ROF system but also used in WDM ROF system.

There are provided a digital RF converter capable of improving a dynamic range and a signal to noise ratio of a transmitter and a digital RF modulator and a transmitter including the same. The digital RF converter may include: a delta-sigma modulated bits (DSMB) sub-block that generates a current magnitude corresponding to least-significant n bits among input signals at a first sampling speed; a least-significant bit (LSB) sub-block that generates a current magnitude corresponding to intermediate k bits among the input signals at a second sampling speed lower than the first sampling speed; and a most-significant bit (MSB) sub block that generates a current magnitude corresponding to most-significant m bits among the inputs signals at the second sampling speed.

A method and system for generating a frequency hopping electromagnetic signal based on a baseband data signal includes a frequency hopping pre-compensator. The frequency hopping pre-compensator determines a frequency hopping pre-compensation signal based on a desired frequency hopping sequence. The frequency hopping pre-compensation signal is combined with the baseband data signal to generate a pre-compensated baseband signal. An RF modulator modulates an RF carrier in accordance with the pre-compensated baseband signal to generate a modulated, frequency hopping RF carrier signal. An amplifier may then amplify the RF carrier signal as desired.

Distributed and highly software reconfigurable CMTS (CMRTS) device, based on MAC and PHY units with FPGA and DSP components, for a HFC CATV network. The various CATV RF modulators, such as QAM modulators, may be divided between QAM modulators located at the cable plant, and remote QAM modulators ideally located at the fiber nodes. A basic set of CATV QAM data waveforms may optionally be transmitted to the nodes using a first fiber, and a second set of IP / on-demand data may be transmitted to the nodes using an alternate fiber or alternate fiber frequency, and optionally using other protocols such as Ethernet protocols. The nodes will extract the data specific to each neighborhood and inject this data into unused QAM channels, thus achieving improved data transmission rates through finer granularity. A computerized “virtual shelf” control system for managing and reconfiguring the FPGA and DSP based CMTRS units is also disclosed.

An electronic device includes a radio frequency (RF) modulator, a power amplifier, and a distortion correction circuit coupled between the RF modulator and the power amplifier. The distortion correction circuit includes a variable gain amplifier coupled between the RF modulator and the power amplifier, and an amplitude correction control loop. The amplitude correction control loop includes a first logarithmic converter having an input coupled to the RF modulator, a second logarithmic converter having an input coupled to an output of the power amplifier, and a difference circuit coupled to outputs of the first and second logarithmic converters for controlling the gain of the variable gain amplifier for correcting distortion in an output signal from the power amplifier.

The invention discloses a photonics broadband microwave IQ modulator and an operating method thereof. The method relates to the technical field of microwaves and the technical field of optical communication. The method is shown in an attached drawing, and comprises a laser diode (LD), a pulse duration modulation-dual parallel Mach-Zehnder modulator (PDM-DPMZM), an optical band pass filter (OBPF) and a photoelectric detector (PD). In the method, a pair of up-converters is constructed by the PDM-DPMZM and the OBPF, so that I-path and Q-path baseband waveforms can be directly modulated on a local oscillator (LO), and a broadband radiofrequency (RF) signal is obtained through the PD. The photonics broadband microwave IQ modulator has a simple structure; the bandwidth of an IQ baseband waveform is large; and the frequency of an LO signal can be tuned in a large range. A phase relationship between the two up-converters can be adjusted flexibly, so that the problem of IQ phase imbalance can be solved. Moreover, the RF signal generated by the IQ modulator has a large isolation degree on the LO, so that LO leakage can be restrained.

An identification card includes a fingerprint sensor, an antenna, a dual-mode radio frequency modulator connected to the antenna and digital circuitry having memory to store a digital word, the digital word including a representation of a fingerprint initially scanned by the fingerprint sensor to identify an individual associated with the identification card. The identification card further includes a control processor connected to the digital circuitry and the radio frequency modulator to communicate a signal to the antenna indicative of a successful match between the fingerprint initially scanned by the fingerprint sensor and newly scanned fingerprint. With such an arrangement, a technique is provided biometrically authenticating the identity of an individual passing through a checkpoint without requiring the individual to stop or exit a vehicle and eliminates the need for a central database of biometric data on individuals.

A Wireless Neural Data Acquisition System, including a headstage, an RF receiver, an analog-to-digital converter, a digital signal processor, and a communication interface; the headstage including: at least one input pre-amplifier band-pass filter and amplifier, a multiplexer (MUX), an RF Modulator comprising a voltage control oscillator (VCO), a transmitting antenna, and a power supply; the RF receiver including: at least one receiving antenna, at least one bandpass filter, at least one amplifier, at least one attenuator, and an FM Demodulator. Also, wireless neural data acquisition headstage and a device for amplifying a signal. Also, a method of neural data monitoring.

The invention provides an optical transmitter with a hybrid modulation format. The optical transmitter is applied to a passive optical access network and a long-distance optical transmission system, wherein the passive optical access network is formed by integrating a wavelength division multiplexer and an optical branching device. The optical transmitter comprises an I / Q modulator 1, an I / Q modulator 2, a delay line interferometer and a Mach-Zehnder modulator. The I / Q modulator 1 is in cascade connection with the delay line interferometer, then is in cascade connection with the I / Q modulator 2 and lastly, is in cascade connection with the Mach-Zehnder modulator. The two I / Q modulators are respectively provided with two data input ports, and the Mach-Zehnder modulator is provided with one data input port. The optical transmitter is controlled to output an optical signal with the self-adaptation hybrid modulation format by controlling the on-off and the signal amplitude of the data input ports and the bit and the phase position delay of the delay line interferometer. By means of the optical transmitter, QPSK modulation, 8 QAM modulation and circular 16 QAM modulation can be achieved, and hybrid transmission formed by various modulation formats in any proportional mode can also be achieved. The optical transmitter can be applied to complex transmission links under the wavelength division multiplexing passive optical network environment, and the frequency spectrum utilization efficiency can be effectively improved.

An RF modulator supporting wide-band signals includes IQ modulation by interleaving the in-phase and quadrature signals. The modulator can be implemented using an integrated circuit having a baseband in-phase stage that receives an in-phase analog input signal, a baseband quadrature stage that receives a quadrature analog input signal, and a switching mixer having a plurality of switches. The switching mixer receives in-phase and quadrature signals from the baseband in-phase stage and the baseband quadrature stage. The switching mixer produces a differential signal combining the in-phase and quadrature signals by interleaving the signals over a plurality of phases of a carrier period.

An RF modulator supporting wide-band signals includes IQ modulation by interleaving the in-phase and quadrature signals. The modulator can be implemented using an integrated circuit having a baseband in-phase stage that receives an in-phase analog input signal, a baseband quadrature stage that receives a quadrature analog input signal, and a switching mixer having a plurality of switches. The switching mixer receives in-phase and quadrature signals from the baseband in-phase stage and the baseband quadrature stage. The switching mixer produces a differential signal combining the in-phase and quadrature signals by interleaving the signals over a plurality of phases of a carrier period.

A method and apparatus prevents interference between a radio signal from RDS-TMC service provider for receiving traffic and travel data by an RDS-TMC receiver and a radio signal for transmitting audio, text, or image data from an FM modulator. The method includes the steps of starting an operation of the receiver system, stopping an operation of the FM modulator while keeping operation of the RDS-TMC receiver, examining whether an RDS-TMC signal from a service provider is available at a current location, receiving the RDS-TMC signal and retrieving RDS-TMC data therefrom, sending the retrieved RDS-TMC data to an audio / video system, and starting the operation of the FM modulator while allowing to output an FM signal from the FM modulator at allowable frequency bands which are outside of a blocked range to send data to the audio / video system.

A phase lock loop RF modulator system including a phase lock loop circuit having a phase detector circuit responsive to an input reference signal and a feedback signal, an oscillator circuit responsive to the phase detector circuit for providing an output signal, a forward path from the phase detector circuit to the oscillator circuit, and a feedback path from the oscillator circuit to the phase detector circuit. The system also includes a first modulation port coupled to the feedback path, a second modulation port coupled to the forward path, and a gain mismatch detection circuit responsive to modulation data and a phase error between the reference signal and the feedback signal for providing an indicator output signal that represents the gain mismatch between the first modulation port and the second modulation port.