CPC H03F 1/02 (2013.01) [H03F 3/245 (2013.01); H04B 1/04 (2013.01); H03F 2200/105 (2013.01); H03F 2200/222 (2013.01); H03F 2200/451 (2013.01); H03F 2200/459 (2013.01); H04B 2001/045 (2013.01)] | 20 Claims |
1. A circuit, comprising:
a transformer that includes a primary coil and a secondary coil, wherein the primary coil is coupled to a first power amplifier (PA) and a second PA, and
wherein the secondary coil is configured to supply a current to a differential antenna based on at least one ripple in the current, a first direction of a first phase of a first amplified constant-envelope signal in the primary coil with respect to a second phase of a second amplified constant-envelope signal in the primary coil;
a ripple detector coupled to at least one of the primary coil or the secondary coil of the transformer, wherein the ripple detector is configured to detect the at least one ripple in the current; and
a load impedance coupled between a median point of the primary coil and ground,
wherein the load impedance is adjusted to match one of an impedance of the differential antenna, an impedance of the first PA, and an impedance of the second PA, and
wherein the load impedance is adjusted based on the ripples detected by the ripple detector.
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