| 摘要 |
PROBLEM TO BE SOLVED: To provide a tunable inter-stage matching circuit for favorably matching impedance between amplifiers in, e.g., a transmitter including a driver amplifier and a power amplifier.SOLUTION: A PA module 230c includes a first active circuit (a driver amplifier 310c), a second active circuit (e.g., a power amplifier 330c), and a tunable inter-stage matching circuit 320c coupled between the first and second active circuits. The tunable inter-stage matching circuit includes a tunable capacitor 628c that can be varied in discrete steps to adjust impedance matching between the first and second active circuits. The tunable capacitor includes (i) a plurality of capacitors 632a-632m coupled in parallel and (ii) a plurality of switches 636a-636m coupled to the plurality of capacitors, one switch for each capacitor. Each switch is turned on to select an associated capacitor and turned off to unselect the associated capacitor. |
