| US 7,479,827 B2 | ||
| Multi-mode power amplifier with high efficiency under backoff operation | ||
| Gary Hau, Merrimack, N.H. (US); and Abid Hussain, Methuen, Mass. (US) | ||
| Assigned to Fairchild Semiconductor Corporation, South Portland, Me. (US) | ||
| Filed on Aug. 20, 2007, as Appl. No. 11/841,162. | ||
| Application 11/841162 is a continuation in part of application No. 11/385948, filed on Mar. 21, 2006. | ||
| Prior Publication US 2008/0030276 A1, Feb. 07, 2008 | ||
| Int. Cl. H03F 1/14 (2006.01) | ||
| U.S. Cl. 330—51 [330/151; 330/302; 330/310] | 17 Claims |
| 1. An RF power amplifier comprising:
a first power amplifier,
a power mode control,
an RF switch responsive to the power mode control;
a first impedance matching circuit,
a second power amplifier,
a second impedance matching circuit, wherein a first path comprises the first power amplifier, the RF switch, the first impedance
matching circuit, the second power amplifier, and the second impedance matching circuit,
a bypass impedance matching circuit, wherein a second path comprises the first power amplifier, the bypass impedance matching
circuit, and the second impedance matching circuit,
wherein, when the RF amplifier is in a first mode, the RF switch is closed and power flows through both the first and the
second paths to an output, and, when the RF amplifier is in a second mode, the RF switch is open and power flows only through
the second path to the output.
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