Gilbert cell mixer

摘要

The invention is implemented in the form of modifications to a Gilbert mixer circuit. The modifications alleviate disadvantages and problems Introduced because of low voltage power supply typically found in low-power devices such as portable cellular phones. In addition to improving the linearity performance, the new design also provides good matching between I and Q signals, and decreases the switching noise in the active mixer by reducing the switching current. The invention can be applied to both single stage and dual mixers to give low noise performance and Automatic Gain Control (AGC).