Patent ID: 8433266

Claim:
A power supply apparatus for a radio frequency power amplifier (RFPA), the power supply apparatus comprising: a voltage controlled voltage source (VCVS) configured to receive a radio frequency (RF) signal; N current controlled current sources (CCCSs), an output end of the VCVS is coupled to output ends of the N CCCSs in parallel; N sampling units and N filtering units, wherein N is an integer greater than or equal to 2, wherein the N sampling units and N filtering units comprise: a first sampling unit, configured to sample the output current of the VCVS to obtain a first sampling signal; a first filtering unit, configured to filter the first sampling signal obtained by the first sampling unit according to a predefined first passband and output the filtered first sampling signal to a first CCCS, thus controlling the output current of the first CCCS; an n th sampling unit, configured to sample a sum of output currents of the first (n−1) CCCSs and the VCVS to obtain an n th sampling signal; and an n th filtering unit, configured to filter the n th sampling signal according to a predefined n th passband and output the filtered n th sampling signal to an n th CCCS, thus controlling an output current of the n th CCCS; wherein the n th passband of the n th filtering unit is lower than an (n−1) th passband of an (n−1) th filtering unit, wherein a switching frequency of the n th CCCS is higher than a switching frequency of an (n−1) th CCCS; and wherein n is an integer greater than or equal to 2 and less than or equal to N.