RF amplifier circuit with a feedback circuit and method for adjusting a gain mode of same circuit

A method for adjusting a gain mode of an RF amplifier circuit, the RF amplifier circuit comprising an amplifier and a feedback circuit, wherein the feedback circuit comprises:

• a resistive feedback circuit having a first node coupled to an input of the amplifier and a second node coupled to an output of the amplifier, the resistive feedback circuit forming a first circuit path in which a first current is configured to flow between the input of the amplifier and the output of the amplifier;
• and
• a shunt feedback circuit having a first node coupled to the output of the amplifier and to the second node of the resistive feedback circuit, and a second node coupled to a reference input, the shunt feedback circuit forming a second circuit path in which a second current is configured to flow between the output of the amplifier and the reference input without flowing through the first circuit path;
• wherein the resistive feedback circuit comprises a first set of serially coupled resistors and a first set of switches, wherein the first set of serially coupled resistors and the first set of switches are arranged in a ladder structure in which each switch of the first set of switches is configured to bypass one of the resistors of the first set of serially coupled resistors in a closed state thereof;
• wherein the shunt feedback circuit comprises a second set of serially coupled resistors and a second set of switches, wherein the second set of serially coupled resistors and the second set of switches are arranged in a ladder structure in which each switch of the second set of switches is configured to bypass one of the resistors of the second set of serially coupled resistors in a closed state thereof;
• and
• wherein the method comprises:
• providing control signals to the switches of the first and second sets of switches in order to adjust the gain mode of the RF amplifier circuit.

An RF amplifier circuit, comprising:

• an amplifier;
• a feedback circuit including:
• a resistive feedback circuit having a first node coupled to an input of the amplifier and a second node coupled to an output of the amplifier, the resistive feedback circuit forming a first circuit path in which a first current is configured to flow between the input of the amplifier and the output of the amplifier, the resistive feedback circuit including a first set of serially coupled resistors and a first set of switches, each switch of the first set of switches configured to bypass one of the resistors of the first set of serially coupled resistors, and
• a shunt feedback circuit having a first node coupled to the output of the amplifier and to the second node of the resistive feedback circuit, and a second node coupled to a reference input, the shunt feedback circuit forming a second circuit path in which a second current is configured to flow between the output of the amplifier and the reference input without flowing through the first circuit path, the shunt feedback circuit including a second set of serially coupled resistors and a second set of switches, each switch of the second set of switches configured to bypass one of the resistors of the second set of serially coupled resistors;
• and
• a control circuit configured to apply control signals to the first and second sets of switches to open and close the switches and control gain modes of the RF amplifier circuit.