Second-order harmonic reduction for radio frequency transmitter

Abstract

Certain aspects of the present disclosure provide methods and apparatus for simultaneous multi-band transmission, including techniques and circuitry for reducing the coupling of a second-order harmonic signal into a victim circuit. One example radio frequency front-end circuit generally includes a first transmit output stage circuit configured to output signals in a first frequency band and a second transmit output stage circuit configured to output signals in a second frequency band. The first transmit output stage circuit generally includes a first adjustable transconductance stage comprising an input stage and a cascode stage coupled to the input stage; and a first adjustable impedance stage coupled to the first adjustable transconductance stage. For certain aspects, the second transmit output stage circuit generally includes a second adjustable transconductance stage and a second adjustable impedance stage coupled to the second adjustable transconductance stage.

Dependencies are inferred from the claim text.