| US 7,515,880 B2 | ||
| Variable gain frequency multiplier | ||
| Dmitriy Rozenblit, Irvine, Calif. (US); Rajasekhar Pullela, Colton, Calif. (US); Tirdad Sowlati, Irvine, Calif. (US); and Shahrzad Tadjpour, Irvine, Calif. (US) | ||
| Assigned to Skyworks Solutions, Inc., Irvine, Calif. (US) | ||
| Filed on Feb. 06, 2006, as Appl. No. 11/348,001. | ||
| Application 11/348001 is a continuation in part of application No. 11/235907, filed on Sep. 27, 2005. | ||
| Prior Publication US 2007/0072556 A1, Mar. 29, 2007 | ||
| Int. Cl. H04B 1/38 (2006.01) | ||
| U.S. Cl. 455—73 [455/78; 455/118; 455/127.1; 455/76; 455/88; 455/180.3; 455/69; 327/93; 327/143; 330/129; 330/140; 330/85] | 17 Claims |
| 13. A portable transceiver having a variable gain frequency multiplier, comprising:
a fully differential receive chain;
a subharmonic mixer in the receive chain, the subharmonic mixer configured to receive a radio frequency (RF) input signal
and a local oscillator (LO) signal that is phase-shifted by a nominal 45 degrees;
a synthesizer having a voltage controlled oscillator and having at least one frequency divider to generate desired transmit
and receive LO signals;
a transmitter having a closed power control loop;
a harmonic rejection modulator, the use thereof made possible by a frequency plan designed to allow the synthesizer to develop
the transmit and receive LO signals without a frequency multiplier; and
a variable gain frequency multiplier comprising:
a frequency multiplier circuit; and
a control circuit coupled to the frequency multiplier circuit and configured to receive a transmitter power control signal,
the transmitter power control signal being proportional to a transmitter power output signal; and
a tuned output circuit, where at a power level below a specified threshold, an output of the freciuency multiplier circuit
bypasses the tuned output circuit.
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