Telefonaktiebolaget Lm Ericsson (publ)

University of California

Donald Kimball

Joseph L Archambault

Walter Haley

Lennart Karl Mathe

Peter M Asbeck

Dewleen Baker

Mingxiong Huang

Jinseong Jeong

Ramesh Rao

Edward Zhong

Imanuel Lerman

Alan Simmons

Bryan Davis

In an example, physiological signal(s) are received from physiological sensor(s) configured to measure at least one physiological property of a user. An arousal of at least one characteristic of at least one treatment resistant mood disorder is detected through employment of an estimation method based at least in part on at least one of the physiological signal(s). A value for at least one of a plurality of stimulation parameters is selected based at least in part on at least one of the physiological signal(s). An electric field based at least in part on the arousal is produced. The electric field is configured to stimulate at least a portion of a median nerve of the user transcutaneously. The electric field is based at least in part on at least some of the plurality of stimulation parameters.

Transcutaneous and transcranial nerve stimulation

An embodiment of the invention is a method of generating a reduced bandwidth envelope signal V(t) for the power supply modulator of an RF amplifier. An envelope signal of an RF amplifier input V(t) is low pass filtered. The filtered envelope signal is subtracted from the envelope signal to obtain a difference signal, which is rectified to produce a residue signal. The residue signal is low pass filtered and added back into the filtered envelope signal. An iterative process of the rectifying, low pass filtering the residue signal adding it back is continued until a condition of V(t)&#x2267;V(t) is met. Another embodiment provides a method of generating a reduced bandwidth envelope signal V(t) for the power supply modulator of an RF amplifier. An envelope signal of an RF amplifier input V(t) is low pass filtered. The filtered envelope signal is subtracted from the envelope signal to obtain a difference signal, which is rectified to produce a residue signal. The residue signal is low pass filtered and multiplied by a first constant that is greater than one, and then added back into the filtered envelope signal. A second constant is added into the filtered envelope signal so that the condition V(t)&#x2267;V(t) is met.

Supply-modulated RF power amplifier and RF amplification methods

A dual feedback topology imparts stability to a multistage linear amplifier, particularly by improving overall amplifier phase margin at higher signal frequencies. With dual feedback, an inner feedback loop is closed around the first amplifier stage, which stage is configured as a current feedback amplifier. A second feedback loop is closed around the overall multistage amplifier. With a current feedback amplifier as the initial stage, the two feedback signals are current-mode signals and thus add to form the combined feedback signal. The frequency responses of the inner and outer feedback loops may be tailored for flat frequency response, or, where desired, may be adjusted to compensate or otherwise flatten overall amplifier frequency response.

Dual feedback linear amplifier

An error amplifier circuit reduces distortion in an amplified signal by reflecting a feedback signal into the amplified signal using an output transformer. A first amplifier generates a reference signal corresponding to the input signal from which the amplifier output signal is derived. This reference signal represents the desired waveform for the amplified signal. An error sense element generates an error signal based on the difference between the reference and amplified signals. The error sense element preferably imparts high common-mode rejection to the error signal. A second amplifier generates the feedback signal based on amplifying the error signal, and an output transformer generates a compensated amplified signal by coupling the feedback signal into the amplified signal. The output transformer increases the reflected load impedance seen by the error amplifier, thus relieving it from driving the feedback signal into the potentially low load impedance driven by the compensated amplified signal.

Wideband error amplifier

A dc voltage converter or dc-RF modulation converter includes an inverting {dot over (C)}uk converter circuit operating under hysteretic feedback control. In an exemplary embodiment, the converter further includes a damping circuit to ensure stability over the extended control frequency bandwidth afforded by the hysteretic control. The converter may further include a non pulse-skipping pulse width control circuit, such that the hysteretic controller's switching signal is limited to maximum and minimum pulse widths, which avoids potential saturation issues where transformer isolation is used for switching the {dot over (C)}uk circuit. In an exemplary application, the converter is used as part of a supply modulation amplifier circuit within a wireless base station, which application capitalizes on the extended bandwidth gained through hysteretic control and reduced circuit complexity by generating signal amplification power directly from the &minus;48 VDC supply rail in the base station.

Cuk style inverter with hysteretic control

A capacitorless DC-DC converter provides a controlled output voltage to a load, and includes a relatively wide bandwidth linear regulator placed in parallel with a switching regulator. Output signals from the linear regulator and switching regulator are added to form a combined output signal provided to the load. The switching regulator provides steady state current to the load, while the linear regulator provides higher-frequency transient current as needed. Because the linear regulator's transient response compensates for the limited transient response of the switching regulator, the substantial low-ESR output capacitance that is customarily required by conventional switching regulators is not needed. Further, feedback to the linear regulator taken from the combined output signal causes it to generate anti-phase ripple compensation, thereby reducing the magnitude of switching ripple in the converter's combined output signal.

Apparatus and method for DC-to-DC power conversion

A wideband precision current sensor employs DC-coupled and AC-coupled sensing circuits to generate lower and higher frequency sense signals; which are combined to form a wideband output signal that is proportional to a wideband current of interest. The frequency response of the wideband output signal is substantially flat across a wideband frequency range, 0 to 30 MHz for example, based on matching the frequency response of the DC- and AC-coupled sensing circuits. In an exemplary application, the current sensor provides feedback to a supply voltage (Vdd) amplifier used in RF envelope elimination and restoration (EER) applications.

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San Diego, CA, United States of America

Donald Kimball