| 摘要 |
A multiple mode RF circuit includes a switching network to switch the RF circuit between a mixer mode and amplifier mode of operation. Two differential amplifier stages coupled to a differential transistor pair form the core of the circuit. A differential local oscillator (LO) source is selectively coupled to the two differential amplifier stages for mixer operation by the switching network and a feedback loop is selectively coupled between the input of the differential transistor pair and the output of the two differential amplifier stages by the switching network for amplifier operation. Gain is controlled in both modes by varying the DC bias on the two differential amplifier stages so that partial cancellation of the amplified signal from the differential transistor pair occur at the RF output. The multiple mode RF circuit operates over a large dynamic range by adjusting a bias current to scale linearity. |
