Transmitter circuit

A transmitter circuit, comprising:

• a signal input for receiving an analog input signal;
• a local oscillator, LO, input for receiving an LO signal;
• a mixer circuit configured to generate a frequency-upconverted signal, wherein the mixer circuit has a first input, a second input, and an output for outputting an output signal of the mixer circuit, and wherein the second input of the mixer circuit is connected to the signal input of the transmitter circuit;
• a power amplifier, PA, circuit having an input connected to the output of the mixer circuit and an output for outputting an output signal of the transmitter circuit;
• a control circuit configured to generate a phase-control signal and a gain-control signal in response to an envelope of the analog input signal;
• a phase-control circuit configured to generate a phase-adjusted LO signal in response to the LO signal and the phase-control signal and to supply the phase-adjusted LO signal to the first input of the mixer circuit;
• and
• a gain-control circuit configured to control a gain of the transmitter circuit in response to the gain-control signal;
• the gain control circuit being located in the mixer circuit and configured to operate on the frequency-upconverted signal to generate a gain-adjusted frequency-upconverted signal;
• and
• the mixer circuit being configured to generate the frequency-upconverted signal in response to the phase-adjusted LO signal and the analog input signal, and to output the gain-adjusted frequency-upconverted signal at the output of the mixer circuit.

A transmitter circuit, comprising:

• a signal input for receiving an analog input signal;
• a local oscillator, LO, input for receiving an LO signal;
• a mixer circuit configured to generate a frequency-upconverted signal, wherein the mixer circuit has a first input, a second input, and an output for outputting an output signal of the mixer circuit, and wherein the second input of the mixer circuit is connected to the signal input of the transmitter circuit;
• a power amplifier, PA, circuit having an input connected to the output of the mixer circuit and an output for outputting an output signal of the transmitter circuit;
• a control circuit configured to generate a phase-control signal and a gain-control signal in response to an envelope of the analog input signal;
• a phase-control circuit configured to generate a phase-adjusted LO signal in response to the LO signal and the phase-control signal and to supply the phase-adjusted LO signal to the first input of the mixer circuit, the phase-control circuit comprising a variable capacitor having a capacitance controlled by the phase-control signal;
• and
• a gain-control circuit configured to control a gain of the transmitter circuit in response to the gain-control signal.

A transmitter circuit, comprising:

• a signal input for receiving an analog input signal;
• a local oscillator, LO, input for receiving an LO signal;
• a mixer circuit configured to generate a frequency-upconverted signal, wherein the mixer circuit has a first input, a second input, and an output for outputting an output signal of the mixer circuit, and wherein the second input of the mixer circuit is connected to the signal input of the transmitter circuit;
• a power amplifier, PA, circuit having an input connected to the output of the mixer circuit and an output for outputting an output signal of the transmitter circuit;
• a control circuit configured to generate a phase-control signal and a gain-control signal in response to an envelope of the analog input signal;
• a phase-control circuit configured to generate a phase-adjusted LO signal in response to the LO signal and the phase-control signal and to supply the phase-adjusted LO signal to the first input of the mixer circuit, the phase-control circuit comprising a current limiting circuit controlled by the phase control circuit;
• and
• a gain-control circuit configured to control a gain of the transmitter circuit in response to the gain-control signal.