Patent ID: 8526905

Claim:
A merged baseband filter-transconductor-upconverter comprising: a baseband filter configured to receive a differential voltage signal at its input, the differential voltage signal having a positive polarity and a negative polarity, and generate at its output a differential baseband filter output; a transconductance block configured to generate a positive polarity transconductance current signal and a negative polarity transconductance current signal, the positive polarity transconductance current signal proportional to the positive polarity of the differential voltage signal and the negative polarity transconductance current signal proportional to the negative polarity of the differential voltage signal; and an upconverter configured to modulate the differential voltage signal and output a differential current signal at its output based on the differential baseband filter output, the differential current signal having a positive polarity and a negative polarity, the upconverter comprising: a first transistor configured to, during a first phase of an oscillator signal, pass the positive polarity transconductance current signal to generate the positive polarity of the differential current; a first switch interfaced between the positive polarity of the differential baseband filter output and the gate of the first transistor, the first switch configured to be closed during the first phase and open during the second phase; a second transistor configured to, during a second phase of an oscillator signal opposite of the first phase, pass the negative polarity transconductance current signal to generate the positive polarity of the differential current; a second switch interfaced between the negative polarity of the differential baseband filter output and the gate of the second transistor, the second switch configured to be open during the first phase and closed during the second phase; a third transistor configured to, during the first phase, pass the negative polarity transconductance current signal to generate the negative polarity of the differential current; a third switch interfaced between the negative polarity of the differential baseband filter output and the gate of the third transistor, the third switch configured to be closed during the first phase and open during the second phase; a fourth transistor configured to, during the second phase, pass the positive polarity transconductance current signal to generate the negative polarity of the differential current; and a fourth switch interfaced between the positive polarity of the differential baseband filter output and the gate of the fourth transistor, the fourth switch configured to be open during the first phase and closed during the second phase.