Radio frequency power amplifier that reduces load change sensitivity, chip, and communication terminal
Disclosed is a radio frequency power amplifier that reduces load change sensitivity, which comprises a feedback circuit ( 10 ) and a plurality of levels of amplification circuit, the feedback circuit ( 10 ) and all or a portion of amplification circuit among the plurality of levels of amplification circuit being connected in parallel between a first node (M) and a second node (N), and a feedback loop made up of the feedback circuit ( 10 ) and an amplification circuit main path located between the first node (M) and the second node (N) forming a 180°+360°×n phase shift, where n is a natural number.
1 . A radio frequency power amplifier, comprising a feedback circuit and a plurality of stages of amplification circuit, the feedback circuit and all or a portion of amplification circuit among the plurality of stages of amplification circuit being connected in parallel between a first node and a second node, and a feedback loop made up of the feedback circuit and an amplification circuit main path located between the first node and the second node forming a 180°+360°×n phase shift, where n is a natural number; wherein
each stage of amplification circuits is composed of an amplification device, and adjacent stages of the plurality of stages of amplification circuits are connected in series with interstage capacitance;
two amplification devices of the plurality of stages of amplification circuits are arranged between the first node and the second node to form a 360° phase shift;
the interstage capacitance between the two amplification devices which are arranged between the first node and the second node, and a feedback capacitance in the feedback circuit forms a 180° phase shift; and
when a load impedance changes, a current flowing to the feedback circuit at the second node fluctuates, thereby changing a phase of a feedback current at the first node to dynamically adjust a size of a combined net input current.
2 . The radio frequency power amplifier according to claim 1 , wherein:
a radio frequency current input to the first node and a feedback current output from the feedback circuit to the first node are in reverse phase under a predetermined load impedance.
3 . The radio frequency power amplifier according to claim 1 , wherein:
one end of the feedback circuit and an output end of a penultimate stage amplification circuit being connected to the second node, and under a condition that the feedback loop forming a 180°+360°×n phase shift, the other end of the feedback circuit is connected to the first node with the input end of a certain stage amplification circuit in front of the penultimate stage amplification circuit.
4 . The radio frequency power amplifier according to claim 1 , wherein:
one end of the feedback circuit and an output end of a penultimate stage amplification circuit being connected to the second node, and under a condition that the feedback loop forming a 180°+360°×n phase shift, the other end of the feedback circuit is connected to the first node with the output end of a certain stage amplification circuit in front of the penultimate stage amplification circuit.
5 . The radio frequency power amplifier according to claim 1 , wherein:
one end of the feedback circuit and an output end of the last stage amplification circuit being connected to the second node, and under a condition that the feedback loop forming a 180°+360°×n phase shift, the other end of the feedback circuit is connected to the first node with the output end of a certain stage amplification circuit in front of the last stage amplification circuit.
6 . The radio frequency power amplifier according to claim 1 , wherein:
one end of the feedback circuit and an output end of the last stage amplification circuit being connected to the second node, and under a condition that the feedback loop forming a 180°+360°×n phase shift, the other end of the feedback circuit is connected to the first node with the input end of a certain stage amplification circuit in front of the last stage amplification circuit.
7 . An integrated circuit chip, comprising the radio frequency power amplifier according to claim 1 .
8 . A communication terminal, comprising the radio frequency power amplifier according to claim 1 .