Abstract: A power amplifier for a radio frequency transceiver including a driver, a disable circuit, and a bias circuit. The driver includes a source node for receiving a drive voltage when enabled and includes an output node that is susceptible to strong blocker signals when disabled. The bias circuit includes first and second bias nodes for driving the voltage level of the source and output nodes, respectively, to suitable bias voltage levels to minimize impact of blocker signals. The disable circuit includes switch circuits to couple the driver to the bias circuit in the disable mode. The bias circuit may include at least one voltage source. The bias circuit may be coupled to a supply voltage and may include a voltage divider coupled between the source and output nodes. The bias circuit may include a source-follower circuit to isolate the bias voltages from variations of the supply voltage.

Abstract: A power amplifier for a radio frequency transceiver including a driver, a disable circuit, and a bias circuit. The driver includes a source node for receiving a drive voltage when enabled and includes an output node that is susceptible to strong blocker signals when disabled. The bias circuit includes first and second bias nodes for driving the voltage level of the source and output nodes, respectively, to suitable bias voltage levels to minimize impact of blocker signals. The disable circuit includes switch circuits to couple the driver to the bias circuit in the disable mode. The bias circuit may include at least one voltage source. The bias circuit may be coupled to a supply voltage and may include a voltage divider coupled between the source and output nodes. The bias circuit may include a source-follower circuit to isolate the bias voltages from variations of the supply voltage.

Abstract: A feedback circuit disposed across input and output terminals of an amplifier is adapted so as not inject DC current back into the input terminal of the amplifier. The feedback circuit includes, in part, first and second current sources, a transistor, and a resistive load. The first current source supplies current to one of the terminals of the transistor in communication with an input terminal of the amplifier. The second current source receives this current and diverts it to a voltage supply. The transistor is maintained in the active region of operation. The resistive load has a first terminal in communication with an output terminal of the amplifier and a second terminal in communication with the transistor. The DC voltages at the two terminals of the resistive load are substantially equal so as to inhibit DC current flow therethrough.

Abstract: A feedback circuit disposed across input and output terminals of an amplifier is adapted so as not inject DC current back into the input terminal of the amplifier. The feedback circuit includes, in part, first and second current sources, a transistor, and a resistive load. The first current source supplies current to one of the terminals of the transistor in communication with an input terminal of the amplifier. The second current source receives this current and diverts it to a voltage supply. The transistor is maintained in the active region of operation. The resistive load has a first terminal in communication with an output terminal of the amplifier and a second terminal in communication with the transistor. The DC voltages at the two terminals of the resistive load are substantially equal so as to inhibit DC current flow therethrough.