Method and circuit for driving a switch-mode amplifier array
A circuit arrangement for generating the drive signals for at least three radio frequency switch-mode amplifiers is described. The circuit arrangement comprises at least two switch-mode amplifiers performing RF out-phasing, and at low RF power level, the average switching frequency—averaged over time and over all switch-mode amplifiers—is less than the radio frequency.
1. A circuit arrangement comprising
a power combiner for combining the output power of switch-mode amplifiers and
at least four switch-mode amplifiers, wherein
at any time, at least one pair of switch-mode amplifiers performs RF out-phasing, and
the number of pairs of switch-mode amplifiers being active is dynamically adapted to the required RF output power.
2. A circuit arrangement for generating the drive signals for at least four radio frequency switch-mode amplifiers, wherein
at any time, at least one pair of switch-mode amplifiers performs RF out-phasing, and
the number of pairs of switch-mode amplifiers is being active is dynamically adapted to the required RF output power.
3. The circuit arrangement of claim 2 , comprising a timing unit based on any of:
at least one DLL
at least one ring-oscillator
a plurality of analog PLLs
a plurality of digital PLLs.
4. Method for generating the drive signals for at least four radio frequency switch-mode amplifiers, wherein
at any time, at least one pair of switch-mode amplifiers performs RF out-phasing, and
the number of pairs of switch-mode amplifiers being active is dynamically adapted to the required RF output power.
5. The method of claim 4 wherein switching events are dynamically mapped to switch-mode amplifiers.
6. Circuit arrangement of claim 1 , wherein the power of switch-mode amplifiers is combined using transformers.
7. Circuit arrangement of claim 1 wherein the power combiner for combining the output power of switch-mode amplifiers comprises
at least one shunt capacitor
at least one series inductive circuit element per switch-mode amplifier, connected between the switch-mode amplifier's output and the shunt capacitor.