An open loop envelope tracking system calibration technique and circuitry are proposed. A radio frequency power amplifier receives a modulated signal. An envelope tracker power converter generates a modulated power amplifier supply voltage for the radio frequency power amplifier based on a control signal derived from the modulated signal. A first output power and a second output power of the radio frequency power amplifier are measured when the control signal is respectively delayed by a first delay period and a second delay period. A sensitivity of the output power of the radio frequency power amplifier is near a maximum near the first delay period and the second delay period. The first delay period and/or the second delay period are adjusted until the first output power substantially equals the second output power. The first delay period and the second delay period are used to obtain a calibrated fine tuning delay offset.

Group delay calibration method for power amplifier envelope tracking

A system and method for performing sample rate conversion and creating fractional delays to a signal is disclosed. The system comprises a filter, a look up table for storing coefficients for sample rate conversion and fractional delays, and control circuitry configured to use an indexing scheme to select one or more coefficients from the look up table for rate conversion and fractional delays. The coefficients stored in the look up table comprise the coefficients required to generate delays in desired increments of a sample rate. In the disclosed method, the one or more coefficients necessary for a desired sample rate and fractional delay are selected from a single look up table and provided to a filter to delay the signal based upon the input sample rate.

Apparatuses and methods for rate conversion and fractional delay calculation using a coefficient look up table

Embodiments disclosed in the detailed description relate to a pseudo-envelope follower power management system used to manage the power delivered to a linear RF power amplifier.

Pseudo-envelope following power management system

Configuration-feedback circuitry and transceiver circuitry are disclosed. The configuration-feedback circuitry regulates an output power from a radio frequency power amplifier based on a difference between a target output power from the radio frequency power amplifier and a measured output power from the radio frequency power amplifier. The transceiver circuitry regulates a modulated power supply voltage, which is used by the radio frequency power amplifier to provide power for amplification, based on the difference between the target output power from the radio frequency power amplifier and the measured output power from the radio frequency power amplifier.

Power loop control based envelope tracking

A power management system for a multi-carriers transmitter is disclosed. The power management system includes a first switcher having a control input and a power output, and a second switcher having a control input and a power output. Also included is a mode switch having a mode control input, wherein the mode switch is adapted to selectively couple the power output of the first switcher to the power output of the second switcher in response to a mode control signal received by the mode control input. Further included is a control system adapted to generate the mode control signal. The control system is coupled to the mode control input of the mode switch.

Power management system for multi-carriers transmitter

A quadrature amplitude demodulator demodulates a modulated signal on which quadrature amplitude modulation is performed. Oscillators generate an in-phase carrier signal having a rectangular wave, a trapezoidal wave or a waveform similar to these, and a quadrature carrier signal, the phase of which is shifted by ¼ cycle relative to the in-phase signal. First and second mixers respectively perform mixing of the modulated signal with the in-phase signal and the quadrature carrier signal. First and second integrators respectively integrate output signals of the first and the second mixers, for a predetermined period in accordance with the cycle of the in-phase carrier signal and the quadrature carrier signal. First and second A/D converters respectively convert outputs of the first and the second integrators into digital values.

Quadrature amplitude demodulator and demodulation method

There is provided a skew adjusting apparatus for adjusting a skew between a positive-side differential signal and a negative-side differential signal in differential signals inputted from an outside device via outside transmission lines, having a positive-side transmission line for propagating the positive-side differential signal inputted to an input end, a negative-side transmission line for propagating the negative-side differential signal inputted to an input end, a plurality of differential comparators connected with the positive-side and negative-side transmission paths so that a difference between wiring length from the input end of the positive-side transmission path and wiring length from the input end of the negative-side transmission path is different from each other and that take in the positive-side differential signal and the negative-side differential signal and a selecting section for selecting a signal taken in by the differential comparator by which a skew between the positive-side path from an output terminal of the positive-side differential signal in the outside device to the differential comparator and the negative-side path from an output terminal of the negative-side differential signal in the outside device to the differential comparator is minimized.

Skew adjusting method, skew adjusting apparatus, and test apparatus

A ring oscillator oscillates at a frequency determined by an input bias signal. A bias signal adjusting unit produces a bias signal for the ring oscillator using feedback so that the oscillation frequency of the ring oscillator matches a predetermined reference frequency. An individual bias circuit includes a plurality of bias circuits provided for a total of N second variable delay elements, respectively. The bias circuits are configured such that the bias signals can be individually adjusted.

Vernier delay circuit

A semiconductor testing apparatus, includes a test signal generating unit that generates a test signal corresponding to a test pattern to output the generated test signal to a device under test (DUT); a comparison signal generating unit that generates a comparison signal by combining a reference signal and the test signal; and a comparing unit that compares a response signal, which is output from the DUT in response to the input of the test signal, and the reference signal by offsetting the test signal contained in a composite signal of the test signal and the response signal and the test signal contained in the comparison signal. The DUT is determined to be defective or not based on a result of comparison by the comparing unit.

Semiconductor testing apparatus and method of testing semiconductor

A variable delay circuit delays a carrier signal having a predetermined frequency, and outputs a modulated signal. A delay setting unit sets a delay period for the variable delay circuit according to a data signal to be modulated. The delay setting unit assigns each symbol in the data signal to any one of positive edges and negative edges in the carrier signal, and sets a delay period for the variable delay circuit at the timing at which a positive edge in the carrier signal passes through the variable delay circuit, according to the symbol value in the data signal assigned to the positive edge. Furthermore, the delay setting unit sets a delay period for the variable delay circuit at the timing at which a negative edge in the carrier signal passes through the variable delay circuit, according to the symbol value in the data signal assigned to the negative edge.

Shoji Kojima

Papers

Quadrature amplitude demodulator and demodulation method

Skew adjusting method, skew adjusting apparatus, and test apparatus

Vernier delay circuit

Semiconductor testing apparatus and method of testing semiconductor

Modulation method and modulator using pulse edge shift