An oscillator circuit includes a first BAW oscillator, a first coupling stage, a second BAW oscillator, and a second coupling stage. The first BAW oscillator is configured to generate a first output signal at a frequency. The first coupling stage is coupled to the first BAW oscillator, and is configured to amplify the first output signal. The second BAW oscillator is coupled to the first coupling stage, and is configured to generate a second output signal at the frequency. The second output signal differs in phase from the first output signal. The second coupling stage is coupled to the first BAW oscillator and the second BAW oscillator, and is configured to amplify the second output signal and drive the first BAW oscillator.

The disclosure concerns an oscillator circuit (10) for a signal transmitter, the oscillator circuit (10) comprising: a resonant circuit (12) comprising a resonant inductor (LR) and a resonant capacitor (CR) parallel to the resonant inductor (LR) or comprising a crystal device, a driving branch (14) comprising a pump capacitor (CP) connected to the resonant circuit (12), a feedback branch (20) connected to the resonant circuit (12), a phase shifting circuit (22) connected to the resonant circuit (12) via the feedback branch (20), a comparator circuit (24) connected to the feedback branch (20) via the phase shifting circuit (22) and a driver circuit (28) connected to an output of the comparator circuit (24) and operable to charge the pump capacitor (CP).

An oscillator circuit includes a first BAW oscillator, a first coupling stage, a second BAW oscillator, and a second coupling stage. The first BAW oscillator is configured to generate a first output signal at a frequency. The first coupling stage is coupled to the first BAW oscillator, and is configured to amplify the first output signal. The second BAW oscillator is coupled to the first coupling stage, and is configured to generate a second output signal at the frequency. The second output signal differs in phase from the first output signal. The second coupling stage is coupled to the first BAW oscillator and the second BAW oscillator, and is configured to amplify the second output signal and drive the first BAW oscillator.