Quadrature modulator and semiconductor integrated circuit with it built-in

A semiconductor integrated circuit comprising:

• a transmission circuit which has first and second D/A converters, first and second low-pass filters, a quadrature modulator, a synthesizer, and a transmission amplifier,
• wherein the first and second D/A converters can convert first and second transmission digital baseband signals into first and second transmission analog baseband signals,
• wherein the first and second low-pass filters can transmit the first and second transmission analog baseband signals to the quadrature modulator,
• wherein the synthesizer can supply first and second RF local signals to the quadrature modulator,
• wherein the quadrature modulator can generate an RF transmission signal as an output, and the transmission amplifier can amplify the RF transmission signal generated from the quadrature modulator,
• wherein the quadrature modulator comprises, a first transistor, a second transistor, a third transistor, a fourth transistor, a first node, a second node, and a first output node,
• wherein each of the first transistor, the second transistor, the third transistor, and the fourth transistor comprises an input electrode, an output electrode, and a control electrode, and a conductive level between the input electrode and the output electrode can be controlled in response to control voltage supplied to the control electrode,
• wherein a non-inversion in-phase analog signal, an inversion in-phase analog signal, a non-inversion quadrature analog signal, and an inversion quadrature analog signal can be supplied to the input electrode of the first transistor, the input electrode of the second transistor, the input electrode of the third transistor, and the input electrode of the fourth transistor, respectively,
• wherein the control electrode of the first transistor, the control electrode of the second transistor, the control electrode of the third transistor, and the control electrode of the fourth transistor can respond to a non-inversion in-phase RF signal, an inversion in-phase RF signal, a non-inversion quadrature RF signal, and an inversion quadrature RF signal, respectively,
• wherein the output electrode of the first transistor and the output electrode of the second transistor are coupled to the first node, and the output electrode of the third transistor and the output electrode of the fourth transistor are coupled to the second node,
• wherein the semiconductor integrated circuit comprises:
• a first high-pass filter coupled between the first node and the first output node;
• and a second high-pass filter coupled between the second node and the first output node,
• wherein the quadrature modulator further comprises a fifth transistor, a sixth transistor, a seventh transistor, an eighth transistor, a third node, a fourth node, and a second output node,
• wherein each of the fifth transistor, the sixth transistor, the seventh transistor, and the eighth transistor comprises an input electrode, an output electrode, and a control electrode, and a conductive level between the input electrode and the output electrode can be controlled in accordance with control voltage supplied to the control electrode,
• wherein the non-inversion in-phase analog signal, the inversion in-phase analog signal, the non-inversion quadrature analog signal, and the inversion quadrature analog signal can be supplied to the input electrode of the fifth transistor, the input electrode of the sixth transistor, the input electrode of the seventh transistor, and the input electrode of the eighth transistor, respectively,
• wherein the control electrode of the fifth transistor, the control electrode of the sixth transistor, the control electrode of the seventh transistor, and the control electrode of the eighth transistor can respond to the inversion in-phase RF signal, the non-inversion in-phase RF signal, the inversion quadrature RF signal, and the non-inversion quadrature RF signal, respectively,
• wherein the output electrode of the fifth transistor and the output electrode of the sixth transistor are coupled to the third node, and the output electrode of the seventh transistor and the output electrode of the eighth transistor are coupled to the fourth node, and
• wherein the quadrature modulator further comprises a third high-pass filter coupled between the third node and the second output node and a fourth high-pass filter coupled between the fourth node and the second output node.