def METHOD_NAME(self, channel):
    """
    Calculate a signal as processed by the tunnel diode.
    The given signal is convolved with the tunnel diode response as in
    AraSim.
    The diode model used in this module returns a dimensionless power trace,
    where the antenna resistance is only a normalisation for the final
    voltage. That's why the antenna resistance has been fixed to a value
    of 8.5 ohms.
    Parameters
    ----------
    channel: Channel
        Signal to be processed by the tunnel diode.
    Returns
    -------
    trace_after_tunnel_diode: array
        Signal output of the tunnel diode for the input `channel`.
        Careful! This trace is dimensionless and comes from a convolution
        of the power with the diode response.
    """
    t_max = 1e-7 * units.s
    antenna_resistance = 8.5 * units.ohm
    n_pts = int(t_max * channel.get_sampling_rate())
    times = np.linspace(0, t_max, n_pts + 1)
    diode_resp = self._td_fdown1(times) + self._td_fdown2(times)
    t_slice = times > self._td_args['up'][1]
    diode_resp[t_slice] += self._td_fup(times[t_slice])
    conv = scipy.signal.convolve(channel.get_trace() ** 2 / antenna_resistance,
                                 diode_resp, mode='full')
    # conv multiplied by dt so that the amplitude stays constant for
    # varying dts (determined emperically, see ARVZAskaryanSignal comments)
    # Setting output
    trace_after_tunnel_diode = conv / channel.get_sampling_rate()
    trace_after_tunnel_diode = trace_after_tunnel_diode[:channel.get_trace().shape[0]]
    # We filter the output if the band is specified
    if self._output_passband != (None, None):
        sampling_rate = channel.get_sampling_rate()
        trace_spectrum = time2freq(trace_after_tunnel_diode, sampling_rate)
        frequencies = np.linspace(0, sampling_rate / 2, len(trace_spectrum))
        if self._output_passband[0] is None:
            b, a = butter(6, self._output_passband[1], 'lowpass', analog=True)
        else:
            b, a = butter(6, self._output_passband, 'bandpass', analog=True)
        w, h = freqs(b, a, frequencies)
        trace_after_tunnel_diode = freq2time(h * trace_spectrum, sampling_rate)
    return trace_after_tunnel_diode