US 7,545,856 B2
Current mode phase shifter, mixer and amplifier
Arya Reza Behzad, Poway, Calif. (US); and Ali Afsahi, San Diego, Calif. (US)
Assigned to Broadcom Corporation, Irvine, Calif. (US)
Filed on Sep. 12, 2005, as Appl. No. 11/224,610.
Claims priority of provisional application 60/715371, filed on Sep. 08, 2005.
Prior Publication US 2007/0058703 A1, Mar. 15, 2007
This patent is subject to a terminal disclaimer.
Int. Cl. H04B 1/38 (2006.01)
U.S. Cl. 375—219  [455/73; 710/1] 20 Claims
OG exemplary drawing
 
1. An integrated circuit radio transceiver, comprising:
a baseband processor operable to process ingoing digital communication signals and to produce outgoing digital communication signals;
a transmitter front end operable to process and transmit outgoing RF signals based upon the outgoing digital communication signals; and
a receiver front end operable to produce the ingoing digital communication signals to the baseband processor based on ingoing RF signals;
a phase shifter that produces a phase shifted input signal;
a high impedance load coupled to an output of the phase shifter;
a low impedance current mixing and amplification stage for generating an amplified frequency shifted output signal to at least a portion of one of the transmitter and receiver front ends, the current mixing and amplification stage further including:
a current mixer operable to produce a frequency shifted output current signal based upon an oscillation and the phase shifted input signal received from the phase shifter, the current mixer characterized by an output impedance;
an amplifier block operably disposed to produce an amplified signal based upon the frequency shifted output current signal, the amplifier block further including an amplifier with at least one feedback resistor;
wherein gain of the amplifier block is based substantially upon a product of a gain characteristic of the current mixer and a resistance value of the at least one feedback resistor; and
wherein the at least one feedback resistor is coupled directly to an input of the amplifier and to a mixer output of the current mixer.