Circuit comprising a current mirror circuit and method for operating a circuit

A method for operating a circuit, the circuit comprising a current mirror circuit with a current path comprising a first transistor and a replica current path comprising a second transistor, wherein the current path is connected to the replica current path, and wherein a capacitor is coupled between a gate of the second transistor and a first potential, the method comprising:

• influencing a current in the replica current path based on a reference current in the current path, the current in the replica current path being proportional to the reference current;
• connecting a gate of the first transistor to the gate of the second transistor and to a first electrode of the capacitor during a first phase;
• selectively disconnecting the gate of the first transistor from the gate of the second transistor and from the first electrode of the capacitor during a second phase;
• generating an output signal, wherein the output signal is a frequency-modulated continuous-wave (FMCW) signal comprising a plurality of frames and a plurality of frequency ramps within each frame of the plurality of frames;
• and
• transmitting the output signal as a high frequency signal during the second phase based on disconnecting the gate of the first transistor from the gate of the second transistor and from the first electrode of the capacitor,
• wherein the high frequency signal corresponds to a frequency ramp, and
• wherein the first phase corresponds to a flyback time of the output signal, the flyback time being a period between two consecutive frequency ramps of the plurality of frequency ramps of a respective frame.

A circuit comprising:

• a current mirror circuit including a current path and a replica current path;
• wherein the current path comprises a first transistor,
• wherein the replica current path comprises a second transistor, and
• wherein the current path is connected to the replica current path to influence a current in the replica current path based on a reference current in the current path, the current in the replica current path being proportional to the reference current,
• a capacitor coupled between a gate of the second transistor of the replica current path and a first potential;
• a switch coupled between a gate of the first transistor of the current path and the gate of the second transistor of the replica current path;
• wherein the switch is configured to selectively disconnect the gate of the first transistor from the gate of the second transistor and from a first electrode of the capacitor, and
• wherein the switch is controllable to connect the gate of the first transistor to the gate of the second transistor and the first electrode of the capacitor during a first phase, and to disconnect the gate of the first transistor from the gate of the second transistor and from the first electrode of the capacitor during a second phase;
• and
• a high frequency circuit configured to generate an output signal, the high frequency circuit comprising a high frequency transmitter controlled to transmit a high frequency signal during the second phase,
• wherein the output signal is a frequency-modulated continuous-wave (FMCW) signal comprising a plurality of frames and a plurality of frequency ramps within each frame of the plurality of frames,
• wherein the first phase corresponds to a non-transmission time between two consecutive frequency ramps of the plurality of frequency ramps of a respective frame, during which no frequency ramp is transmitted, and
• wherein the second phase corresponds a transmission time of each frequency ramp of the plurality of frequency ramps.