Patent ID: 6927629

Claim:
A differential amplifier that receives first and second input signals and generates first and second output signals, the differential amplifier comprising: a first differential converter including a first grounded emitter amplifier that receives the first input signal and generates a first differential output signal, and a first grounded base amplifier that receives the first input signal and generates a second differential output signal; and a second differential converter including a second grounded emitter amplifier that receives the second input signal and generates a third differential output signal, and a second grounded base amplifier that receives the second input signal and generates a fourth differential output signal; wherein the first output signal is generated by coupling the first differential output signal and the fourth differential output signal, and the second output signal is generated by coupling the second differential output signal and the third differential output signal, wherein the first grounded emitter amplifier includes: a first transistor, a first resistor connected between an emitter of the first transistor and a ground, a first capacitor connected to a base of the first transistor, for receiving the first input signal, and a second resistor connected between the base of the first transistor and a bias voltage; the first grounded base amplifier includes: a second transistor, a second capacitor connected between a base of the second transistor and the ground, a third resistor connected between the base of the second transistor and the bias voltage, a third capacitor connected to an emitter of the second transistor, for receiving the first input signal, and a fourth resistor connected between the emitter of the second transistor and the ground; the second grounded emitter amplifier includes: a third transistor, a fifth resistor connected between an emitter of the third transistor and the ground, a fourth capacitor connected to a base of the third transistor, for receiving the second input signal, and a sixth resistor connected between the base of the third transistor and the bias voltage; and the second grounded base amplifier includes: a fourth transistor, a fifth capacitor connected between a base of the fourth transistor and the ground, a seventh resistor connected between the base of the fourth transistor and the bias voltage, a sixth capacitor connected to an emitter of the fourth transistor, for receiving the second input signal, and an eighth resistor connected between the emitter of the fourth transistor and the ground; wherein a collector of the first transistor is connected to a collector of the fourth transistor, and a collector of the second transistor is connected to a collector of the third transistor.