Patent ID: 8736400

Claim:
A bandpass filter comprising at least one first oscillating circuit formed of a first inductive means in parallel with a first capacitive means and of a second oscillating circuit comprising a second inductive means arranged in parallel with a second capacitive means, the first oscillating circuit being coupled to the second oscillating circuit, characterized in that the first capacitive means of the first oscillating circuit comprises an assembly of a plurality of variable capacitive elements in series with a first fixed capacitor, a first midpoint between two of the variable capacitive elements of the first capacitive means, a second midpoint between two of the variable capacitive elements of the first capacitive means, the second midpoint being spaced from the first midpoint by at least one of the variable capacitive elements of the first capacitive means, and in that the second capacitive means of the second oscillating circuit comprises an assembly of a plurality of variable capacitive elements arranged in series with a second fixed capacitor, a third midpoint between two of the variable capacitive elements of the second capacitive means, a fourth midpoint between two of the variable capacitive elements of the second capacitive means, the fourth midpoint being spaced from the third midpoint by at least one of the variable capacitive elements of the second capacitive means, and in that the first oscillating circuit and the second oscillating circuit are coupled by means of capacitive coupling elements of substantially fixed value and in that at least one of the capacitive coupling elements is linked to the first midpoint and the third midpoint, and at least another of the capacitive coupling elements is linked to the second midpoint and the fourth midpoint.