The present disclosure includes systems and techniques relating to time-varying notch filter. In some implementations, an apparatus includes a time-variant notch filter and a controller. The time-variant notch filter includes a notch depth and a notch bandwidth. At least one of the notch depth or the notch bandwidth is based on a coefficient of the notch filter. The controller is configured to set at least one of the notch depth to a first depth or the notch bandwidth to a first bandwidth by setting a value of the coefficient to a first value during a ramp-up of the notch filter before a packet is received. The controller is also configured to set at least one of the notch depth to a second depth or the notch bandwidth to a second bandwidth by adjusting the value of the coefficient to a second value after the packet is received.