A transmission circuit includes a power amplifier, a power amplifier forestage circuit and a signal strength adjusting circuit. The power amplifier is configured to amplify an input signal to output an output signal. The power amplifier forestage circuit is configured to output the input signal. The signal strength adjusting circuit includes a conversion circuit, a processing circuit and a storage unit. The conversion circuit is configured to convert the voltage of the output signal into an operation value. The processing circuit is configured to perform an operation according to a target index value stored by the storage unit and the operation value to obtain a differential value. The processing circuit is further configured to adjust the input signal outputted by the power amplifier forestage circuit according to the differential value, so that the power of the output signal is maintained at a target power value.

An RF power detector adapted to detect an RF power of an RF signal, includes, in part, an antenna adapted to receive the RF signal, a narrow-band RF power converter adapted to convert the RF signal to a DC signal, an accelerometer, and a magnetometer. The accelerometer and magnetometer are adapted to determine the orientation and location of the power detector. The power detector optionally includes a gyroscope. The narrow-band RF power converter may be a rectifier tuned to the frequency of the RF signal. The power detector optionally includes an indicator adapted to provide information representative of the amount of the DC power of the DC signal, as well as position and orientation of the power detector. The power detector may be adapted to be inserted into a mobile device so as to provide the information about the amount of DC power, orientation and position to the mobile device.

A peak detector for a power amplifier is provided that includes a threshold voltage detector configured to pulse a detection current in response to an amplified output signal from the amplifier exceeding a peak threshold. A plurality of such peak detectors may be integrated with a corresponding plurality of power amplifiers in a transmitter. Should any peak detector assert an alarm signal or more than a threshold number of alarm signals during a given period, a controller reduces a gain for the plurality of power amplifiers.

An optical receiver disclosed includes a bias terminal, an input terminal, a photodiode, an amplifier circuit, a first resistor, a bypass circuit, a filter circuit, and a control circuit. The photodiode receives a bias from the filter circuit through the bias terminal, and outputs a current signal to the amplifier circuit through the input terminal. The amplifier circuit converts an input current to an output voltage. The bypass circuit electrically connected to the input terminal decreases a first input impedance viewed from the input terminal, when activated, and increases the first input impedance, when deactivated. The filter circuit increases a second input impedance viewed from the bias terminal, when a dumping function thereof is activated, and decreases the second input impedance, when the dumping function is deactivated. The control circuit activates the dumping function and the bypass circuit, when the output voltage is larger than a certain voltage.

The present disclosure generally relates to techniques and apparatus for implementing an envelope-tracking power supply for a radio frequency (RF) power amplifier. One aspect includes an amplification system. The amplification system may include a first amplifier configured to generate an amplifier output voltage, a second amplifier having an output coupled to a supply node for the first amplifier, a voltage regulator having an output coupled to a supply node for the second amplifier, and control circuitry configured to control the voltage regulator to generate a supply voltage at the supply node for the second amplifier based on an indication associated with the amplifier output voltage. In some aspects, the control circuitry may be configured to control the voltage regulator through at least providing an updated control setting for the voltage regulator with a periodicity associated with a power control period.

An apparatus comprises a transistor pair including a first metal oxide semiconductor field effect transistor (MOSFET) coupled to a second MOSFET. The first MOSFET includes a first gate terminal and a first drain terminal. The second MOSFET comprises a second gate terminal and a second drain terminal. The first gate terminal is configured to receive a first signal. The second gate terminal is configured to receive a second signal that is phase shifted with respect to the first signal. An output node is coupled to the first drain terminal and the second drain terminal and configured to output a third signal that is proportional to a power of the first signal and the second signal.

A protection circuit and method for protecting driven circuitry against voltage peaks in a radio frequency signal, “V.sub.RF”, past a predetermined voltage level “V.sub.detect”. The protection circuit includes an input for receiving the radio frequency signal. The protection circuit also includes at least one amplification stage coupled to the input. The amplification stage is operable to produce an amplified signal based on V.sub.detect−V.sub.RF. The protection circuit further includes a hold circuit operable to determine, from the amplified signal produced by the amplification stage, whether a peak voltage V.sub.peak of the radio frequency signal exceeds V.sub.detect. The hold circuit is operable to output a first detection value if V.sub.peak exceeds V.sub.detect. The hold circuit is operable to output a second detection value if V.sub.peak does not exceed V.sub.detect. The protection circuit also includes a latch circuit operable to latch the detection value outputted by the hold circuit.

Disclosed is a system for monitoring the peak power of a telecommunication signal to be transmitted for RF power amplification of the telecommunication signal to be transmitted, including a digital processing device, a digital to RF converter and a dc-dc converter, wherein the output of the dc-dc converter can take a discrete voltage value from N discrete voltage values, N being an integer equal to or greater than 2, the digital processing device including a processing path including an envelope tracking control logic adapted to create a continuous envelope tracking control signal. The processing path further includes logic for driving the dc-dc converter including a peak value calculating device and a power supply voltage selecting device.

Techniques for efficiently generating a variable boosted supply voltage for an amplifier and/or other circuits are disclosed. In an exemplary design, an apparatus includes an amplifier, a boost converter, and a boost controller. The amplifier receives an envelope signal and a variable boosted supply voltage and provides an output voltage and an output current. The boost converter receives a power supply voltage and at least one signal determined based on the envelope signal and generates the variable boosted supply voltage based on the power supply voltage and the at least one signal. The boost controller generates the at least one signal (e.g., an enable signal and/or a threshold voltage) for the boost converter based on the envelope signal and/or the output voltage. The boost converter is enabled or disabled based on the enable signal and generates the variable boosted supply voltage based on the power supply voltage and the threshold voltage.

An envelope tracking (ET) power management apparatus incorporating multiple power amplifiers is provided. The ET power management apparatus includes a single ET integrated circuit (ETIC) configured to provide multiple ET voltages to the multiple power amplifiers for amplifying a radio frequency (RF) signal concurrently. The ETIC includes multiple first ET voltage circuits configured to generate multiple first ET voltages and a second ET voltage circuit configured to generate a second ET voltage. The ETIC is configured to provide each of the first ET voltages to an output stage amplifier(s) in a respective one of the power amplifiers and provide the second ET voltage to a driver stage amplifier in all of the power amplifiers. By supporting the multiple power amplifiers using a single ETIC, it is possible to reduce footprint, power consumption, and heat dissipation in an electronic device employing the ET power management apparatus.