An amplifying apparatus for linearly amplifying a desired signal using a pair of coupled non-linear amplifiers is disclosed. The amplifying apparatus comprises a limiter for separating amplitude variations from the desired signal and producing a constant amplitude signal bearing the phase of the desired signal and an amplitude related signal. In addition, a drive signal generater produces two drive signals each dependent on the constant amplitude signal and the amplitude related signal such that each drive signal depends on the phase of the desired signal and such that the sum of the squares of the amplitudes of the drive signals is constant. Finally, a coupler couples the two drive signals to produce two constant amplitude signals for driving the pair of non-linear power amplifiers and for coupling the outputs of the power amplifiers to produce two amplified output signals, one of which is the linearly amplified desired signal and the other of which is a waste energy signal.

Waste energy control and management in power amplifiers

To allow meter data users to have access to needed information and at the same time address the rapidly shifting requirements of the deregulated marketplace, a new business model, apparatus and system are provided. A common metering device measures raw data and a system composed of independent services or applications collect and process raw metered data and then make that data available to interested parties. This new model removes the dependence upon an automatic meter reading (AMR) system provider, as the sole provider, by creating a system to enable a competitive environment where services (applications, information, networking, etc.) rather than systems are selected and paid for on a leased or pay-per-use basis. One example of such a networked-based, extensible metering system comprises a network server, a wide area network coupled to the network server, and a plurality of network-enabled meters coupled to the network. The meters collect data and the network server provides at least one metering application to the meters. In addition, the meters may be programmed to communicate via a predefined protocol and to deliver a protocol interface to a storage medium on the network, which enables the network to provide the protocol interface to users or applications requiring information from the meters and the users/applications to communicate with the meters to access the required information.

Network-enabled, extensible metering system

Efficient PAM transmit modulation is provided by a PAM modulator that includes an oscillator ( 404 ) that provides a clock signal, CKV, ( 408 ). The clock signal 408 and a delayed version (CKV_DLY) 420 of the clock signal are provided to a logic gate ( 414 ). The output of logic gate ( 414 ) is used as a power amplifier input signal (PA_IN) for radio frequency power amplifier ( 416 ). Depending on the relative time delay of the CKV clock signal ( 408 ) and the CKV_DLY delayed clock signal ( 420 ), the timing and duty cycle of the logic gate ( 414 ) duty cycle can be controlled. The duty cycle or pulse-width variation affects the turn-on time of the power amplifier ( 416 ); thereby establishing the RF output amplitude.

Efficient pulse amplitude modulation transmit modulation

A switch-mode power supply includes the series combination of an inductor and a controllable switch adapted to be coupled to a voltage source for producing a succession of increasing and decreasing ramp currents through the inductor. The average value of the ramp currents is controlled by a feedback loop. A second controllable switch arrangement is coupled for causing the current leaving the inductor to recirculate through the inductor during those intervals in which the second switch is conductive. An integrator is coupled to the inductor for integrating ramp current from the inductor during those intervals in which the second switch is nonconductive, for generating load voltage. A second feedback arrangement senses the load voltage and controls the average conduction of the second switch to control the load voltage. In one embodiment, an inverter receives ramp current from the inductor and generates alternating current, which are transformed and rectified before application to the integrator.

Switching regulator with rapid transient response

Systems, devices and methods for communication include an ear canal microphone configured for placement in the ear canal to detect high frequency sound localization cues. An external microphone positioned away from the ear canal can detect low frequency sound, such that feedback can be substantially reduced. The canal microphone and the external microphone are coupled to a transducer, such that the user perceives sound from the external microphone and the canal microphone with high frequency localization cues and decreased feedback. Wireless circuitry can be configured to connect to many devices with a wireless protocol, such that the user can receive and transmit audio signals. A bone conduction sensor can detect near-end speech of the user for transmission with the wireless circuitry in noisy environment. Noise cancellation of background sounds near the user can improve the user's hearing of desired sounds.

Multifunction System and Method for Integrated Hearing and Communication with Noise Cancellation and Feedback Management

An AM transmitter includes an RF signal generator and a switching-type RF signal amplifier. The RF amplifier output depends upon the energizing voltage applied thereacross, so it acts as a modulator. The energizing voltage is produced by a high-power audio amplifier which includes a pulse-width modulator driving a high-power audio switch. The switch terminals are coupled in series with an audio-frequency filter, energizing terminals of the RF amplifier and a source of direct energizing potential, for varying the voltage across the RF amplifier at an audio rate in response to the duty cycle of the width-modulated pulses for audio modulating the RF carrier. In order to reduce modulation distortion at low duty cycles resulting from the finite turn-on and turn-off time of the audio switch, an offset voltage generator is coupled to the filter by a diode. Energy stored in inductive components of the filter cause a voltage pulse during each turn-off of the audio switch. The voltage pulse is coupled to the offset voltage generator by the diode, and the voltage at the filter is maintained at the offset voltage while current flows in the offset voltage generator and the inductors lose energy. The offset generator includes a capacitor for storing energy resulting from the current flow in the inductor. A DC to AC inverter is coupled to the capacitor and generates alternating voltage. The AC is rectified and a pulsating direct current is coupled to the energizing source for recovering the energy in the inductive pulse.

Roger E. Wolf

Papers

Radio transmitter energy recovery system