A calibration device (CD) is dedicated to a RF band-pass filter (RFF) comprising a means (FM) for filtering a
frequency band depending on the value of a control
voltage applied by a controllable power supply means (PSM). This device (CD) comprises i) a generator (GM) for feeding the filter means (FM) with a test
signal of a chosen frequency, ii) a means (MM) arranged to measure the output power values of the test
signal at the filter means output, and iii) a control means (CM) arranged a) to order the power supply means (PSM) to apply successive increasing control voltages as long as the output power value increases, reaches a maximum value and then begins to decrease, then b) to store the first decreasing output power value and the corresponding control
voltage, then c) to order the power supply means (PSM); to apply successive decreasing control voltages as long as the output power value increases, reaches said maximum value and then begins to decrease to a last output power value, and then d) to determine a control
voltage corresponding to a maximum of the filter output power at the chosen frequency from the stored control voltage and the control voltage applied last and corresponding to the last output power value.