Integrated Up-Conversion Mixer With Embedded Low-Pass Filtering

The patent combines the baseband filter and up-conversion mixer into a single integrated circuit module. The filter section processes baseband signals (I and Q channels) through differential filtering, while the mixer section simultaneously performs frequency up-conversion by mixing filtered signals with local oscillator signals. This merging eliminates the need for separate filter and mixer circuits, reducing chip area while preserving the high linearity performance of both components through careful circuit design and signal path optimization.

The integrated circuit combines filtering and mixing functions in a single architecture, allowing shared use of active devices and signal paths. The differential filter structure uses coupled transconductance stages that simultaneously perform filtering and signal conditioning for the subsequent mixer stage, reducing redundant current consumption. The mixer section efficiently utilizes the filtered differential signals with minimal additional current draw, achieving high linearity conversion with lower total power consumption compared to separate implementations.

The patent implements a unified circuit architecture where the filter and mixer sections are integrated but functionally distinct. The filter section uses differential RC or active filter stages that process I and Q baseband signals independently, maintaining optimal filtering performance. The mixer section immediately follows, using the filtered differential signals as inputs to frequency up-conversion circuitry. This integrated design reduces the number of discrete components, interconnections, and control circuits needed, simplifying overall device complexity while preserving independent optimization of both filtering and mixing functions within the unified structure.