Radio frequency doubler and tripler

The invention relates to a radio frequency doubler and a tripler. In an embodiment, a radio frequency multiplier includes: a first transistor and a second transistor connected in parallel between a first differential output and a first terminal of a current source configured to provide a bias current, a second terminal of the current source connected to a first power supply potential; a third transistor connected between the first terminal of the current source and the second differential output; a circuit configured to apply an AC component of the first differential input and a first DC voltage to a gate of the first transistor, apply an AC component of the second differential input and the first DC voltage to a gate of the second transistor, and apply a second DC voltage to a gate of the third transistor; and a feedback loop configured to control the first voltage or the second voltage according to a difference between the DC component of the first differential output and the DC component of the second diff