A change in a detection voltage due to the temperature is suppressed. A detector circuit includes: a first rectification element having an anode to which an input signal is inputted; a second rectification element having a cathode connected with a cathode of the first rectification element and having an anode connected to an output terminal; and a current mirror circuit for supplying a current to the first rectification element, and for supplying a current-mirror current of the current to the second rectification element.

Various envelope tracking amplifiers are presented that can be switched between an ET (envelope tracking) mode and a non-ET mode. Switches and/or tunable components are utilized in constructing the envelope tracking amplifiers that can be switched between the ET mode and the non-ET mode.

A demodulator circuit receives an envelope signal for comparison against a switched reference signal that is generated as a function of the envelope signal and as a function of an output signal of the demodulator circuit. The switched reference signal is filtered by an RC filter prior to comparison. The output signal is dependent on a difference between the filtered switched reference signal and the envelope signal.

A demodulator circuit receives an envelope signal for comparison against a switched reference signal that is generated as a function of the envelope signal and as a function of an output signal of the demodulator circuit. The switched reference signal is filtered by an RC filter prior to comparison. The output signal is dependent on a difference between the filtered switched reference signal and the envelope signal.

An envelope tracking amplifier having stacked transistors is presented. The envelope tracking amplifier uses dynamic bias voltages at one or more gates of the stacked transistors in addition to a dynamic bias voltage at a drain of a transistor.

Control systems and methods for power amplifiers operating in envelope tracking mode are presented. A set of corresponding functions and modules are described and various possible system configurations using such functions and modules are presented.

Described is a circuit for supplying power to an electric load connected to the circuit via an interface, and for receiving desired signals transmitted from the electric load by an amplitude modulation, performed by the electric load, of a carrier signal transmitted from the circuit via the interface, said carrier signal serving to supply power to the electric load, with a carrier signal generator that comprises a direct voltage source and a DC-AC converter downstream of the direct voltage source, and with a demodulator for extraction of desired signals modulated by the electric load on the carrier signal, which circuit has a high efficiency without the use of choke coils. The demodulator is designed to extract the desired signals using a current corresponding to a carrier signal current flowing through a current path of the circuit during a transmission of the desired signals, said carrier signal current flowing across the interface.

Described is a circuit for supplying power to an electric load connected to the circuit via an interface, and for receiving desired signals transmitted from the electric load by an amplitude modulation, performed by the electric load, of a carrier signal transmitted from the circuit via the interface, said carrier signal serving to supply power to the electric load, with a carrier signal generator that comprises a direct voltage source and a DC-AC converter downstream of the direct voltage source, and with a demodulator for extraction of desired signals modulated by the electric load on the carrier signal, which circuit has a high efficiency without the use of choke coils. The demodulator is designed to extract the desired signals using a current corresponding to a carrier signal current flowing through a current path of the circuit during a transmission of the desired signals, said carrier signal current flowing across the interface.

An envelope tracking amplifier having stacked transistors is presented. The envelope tracking amplifier uses dynamic bias voltages at one or more gates of the stacked transistors in addition to a dynamic bias voltage at a drain of a transistor.

The present invention relates to a differential envelope detector, which comprises: input terminals for separating cathode and anode components from a signal and receiving same; a first voltage output unit for outputting a first common mode voltage between the input terminals; a first amplification unit, which receives an input signal as a differential pair and amplifies same so as to output a first output signal; a second amplification unit, which receives the first common mode voltage so as to output a second output signal; and a second voltage output unit for outputting a second common mode voltage between a constant current source unit and an output terminal, wherein the output size of the detector is hardly affected by temperature changes, and an output DC voltage is also fixed so as to be effective with respect to input bias of the next stage amplifier.