| 摘要 |
<p>An amplifier circuit 300 for a radio frequency transceiver includes a common amplifier 301 arranged in a common-gate configuration between an antenna 305 and a first node; a transmit amplifier 303 operable to amplify an input signal from input node 315 and provide the amplified signal to the first node; and a receive amplifier 302 operable to amplify a radio frequency signal present at said first node and provide the amplified signal to an output node 314. The circuit is operable in two modes: in a receive mode, the common and receive amplifiers are configured so as to together form a receive cascode low noise amplifier for amplifying radio frequency signals received at the antenna; and in a transmit mode, the common and transmit amplifiers are configured so as to together form a transmit cascode power amplifier for amplifying radio frequency signals applied at the input node. Preferably a DC bias voltage is applied to the antenna side terminal of the common amplifier using a choke 304. The value of the DC bias is used to toggle the circuit between the two different modes.</p> |
