In an embodiment, a circuit for tripling frequency is configured to receive an input voltage (Vin) having a sinusoidal shape and a base frequency. The circuit has a first and a second transistor pair that are cross-coupled, and a trans-characteristics f(Vin) approximating a polynomial nominal trans-characteristic given by f ⁡ ( V in ) = ( 3 A ⁢ V in - 4 A 3 ⁢ V in 3 ) ⁢ g m where A represents an amplitude of the input voltage and gm is a transconductance of transistors of the first and second transistor pairs.