A resistor in a pair of resistors is selectively coupled to a current source through a selection switch during the reset phase of a voltage-mode sense amplifier so that one evaluation node for the voltage-mode sense amplifier is discharged from a power supply voltage by an ohmic voltage drop across the selectively-coupled resistor to null an offset for the voltage-mode sense amplifier.

An amplifier circuit includes: an input circuit configured to receive an input signal; a load circuit provided in series with the input circuit and including a first variable resistance unit and a second variable resistance unit, a resistance value of the first variable resistance unit being controlled by, a digital code, a resistance value of the second variable resistance unit being controlled by an analog control voltage; and a correction circuit including a third variable resistance unit having a circuit configuration corresponding to the first variable resistance unit and a fourth variable resistance unit having a circuit configuration corresponding to the second resistance unit, a resistance value of the third variable resistance unit being controlled by the digital code, a resistance value of the fourth variable resistance unit being controlled by the analog control voltage, the correction circuit being configured correct a resistance value of the load circuit.

The present application discloses a trimming circuit of differential amplifier, wherein an output end of the differential amplifier is coupled to a first input end of the differential amplifier through a first voltage-dividing resistor; a shift voltage is coupled to a second input end of the differential amplifier through a second voltage-dividing resistor; the first voltage-dividing resistor and the second voltage-dividing resistor respectively form a T-shaped resistor network structure; the T-shaped resistor network structure comprises: a k-bit resistive network coupled to a T-shaped node and a reference power supply end, wherein a low n-bits of the k-bit resistive network is an R-2R resistive network, and part of branches are connected in series with at least one trimming resistor, and each trimming resistor is connected in parallel with a switch.

According to an example aspect of the present invention, there is provided an apparatus for an antenna, comprising, a first power amplifier and a second power amplifier and a common ground between the first power amplifier and the second power amplifier, wherein a Radio Frequency, RF, output of the first power amplifier is coupled to the common ground and a RF output of the second power amplifier is coupled to the common ground.