A push-push oscillator circuit with a first oscillation branch with a first active device and a first tank adapted to provide a signal having a fundamental frequency f0, a second oscillation branch with a second active device and a second tank symmetrical to the first oscillation branch and adapted to provide a signal having the fundamental frequency f0. Output branches are coupled to the first oscillation branch and the second oscillation branch to provide signals having the second harmonic frequency 2f0 of the fundamental signal based on the signals having the fundamental frequency f0 and/or to provide signals having the fundamental frequency f0; The push-push oscillator circuit further comprises at least one terminal branch with a terminal adapted to provide a component of a differential signal having the second harmonic frequency 2f0 or the fundamental frequency f0. The at least one terminal branch comprises a RF stub.