Front-end circuit

A front-end, circuit which receives a first input signal and a second input signal, and outputs an output signal having a differential frequency between the first input signal and the second input signal comprising:

• a first amplifier having an input terminal, a power supply terminal and a ground;
• a second amplifier having an input terminal, a power supply terminal and a ground;
• and a mixer having a first and a second input terminals, a power supply terminal and a virtual ground, wherein
• the virtual ground of the mixer is dc-coupled to the power supply terminal of the first and the second amplifier;
• the power supply terminal of the first amplifier and the second amplifier are ac-coupled to the first and the second input terminals, respectively, and wherein
• the input terminal of the first amplifier and the input terminal of the second amplifier receive the first and the second input signals, respectively;
• and a power supply voltage is supplied to the power supply terminal of the mixer and the ground.

A front-end circuit which receives a first input signal and a second input signal, and outputs an output signal having a differential frequency between the first input signal and the second input signal comprising:

• a first amplifier having an input terminal, a power supply terminal and a virtual ground;
• a second amplifier having an input terminal, a power supply terminal and a ground;
• and a mixer having a first and a second input terminals, a power supply terminal and a virtual ground, wherein
• the power supply terminal of the first amplifier and the second amplifier are ac-coupled to the first and the second input terminals, respectively;
• the input terminal of the first amplifier and the input terminal of the second amplifier receive the first and the second input signals, respectively, and wherein
• the first amplifier, the second amplifier and the mixer are connected in series such that currents flowing in the power supply terminals of the first amplifier, the second amplifier and the mixer are substantially same.

A front-end circuit which receives a first input signal and a second input signal, and outputs an output signal having a differential frequency between the first input signal and the second input signal comprising:

• a first amplifier having an input terminal, a power supply terminal and a virtual ground;
• a second amplifier having an input terminal, a power supply terminal and a ground;
• and a mixer having a first and a second input terminals, a power supply terminal and a virtual ground, wherein
• the power supply terminal of the first amplifier and the second amplifier are ac-coupled to the first and the second input terminals, respectively;
• the input terminal of the first amplifier and the input terminal of the second amplifier receive the first and the second input signals, respectively, and wherein
• the first amplifier, the second amplifier and the mixer are connected such that a summation of currents flowing in the power supply terminals of the first amplifier and the second amplifier is substantially same as a current flowing in the power supply terminal of the mixer.