US 11,705,869 B2
Low-load-modulation power amplifier
Bi Ngoc Pham, Attleboro, MA (US); and Gerard Bouisse, Toulouse (FR)
Assigned to MACOM TECHNOLOGY SOLUTIONS HOLDINGS, INC., Lowell, MA (US)
Filed by MACOM Technology Solutions Holdings, Inc., Lowell, MA (US)
Filed on Oct. 4, 2019, as Appl. No. 16/593,072.
Claims priority of application No. 18/59231 (FR), filed on Oct. 5, 2018.
Prior Publication US 2020/0112287 A1, Apr. 9, 2020
Int. Cl. H03F 1/02 (2006.01); H02M 7/48 (2007.01); H03F 3/19 (2006.01); H03F 3/21 (2006.01)
CPC H03F 1/0288 (2013.01) [H02M 7/48 (2013.01); H03F 1/0277 (2013.01); H03F 3/19 (2013.01); H03F 3/21 (2013.01)] 31 Claims
OG exemplary drawing
 
1. A power amplifier comprising:
a main amplifier having a main output coupled to a first node;
a first peaking amplifier having a first output coupled to the first node;
a first impedance inverter connected between the first node and a second node; and
a second peaking amplifier having a second output coupled to the second node, wherein:
no impedance inverter is connected between the second output of the second peaking amplifier and the second node;
the main amplifier, first peaking amplifier, and second peaking amplifier are in three parallel circuit branches;
a maximum power output by the main amplifier differs from a maximum power output by the first peaking amplifier and from a maximum power output by the second peaking amplifier such that a peak back-off efficiency for the power amplifier is less than 9.54 dB;
a load modulation ratio MR for the power amplifier comprises a ratio of an impedance seen by the main amplifier when the first peaking amplifier and the second peaking amplifier are fully backed-off to the impedance seen by the main amplifier when the first peaking amplifier and the second peaking amplifier are fully amplifying at the maximum power output; and
the MR for the power amplifier is equal to or less than 1.8.