Cell part for electromechanical band-pass filter - has resonators and coupler which vibrate longitudinally with rod structures having dia. given by prescribed formula

The cell forms part of an electromechanical band-pass filter, and has two opposite cylindrical rods forming longitudinally vibrating resonators and one cylindrical longitudinally vibrating coupler connected between the two resonators. The diameter of the coupler is defined by the formula involving the resonator dia., density of its material as well as that of the resonator and the speed of sound on the resonator. The formula also involves the higher relative frequency of the frequency band to be transmitted and the lower relative frequency of the frequency band to be transmitted as well as the wavelength at the first tuned frequency of the resonators. Filters built with this cell are more accurate even for wide bandwidths. LA PRESENTE INVENTION CONCERNE DES CELLULES POUR UN FILTRE ELECTROMECANIQUE A RESONATEURS ET COUPLEURS VIBRANT LONGITUDINALEMENT.CHAQUE CELLULE ELEMENTAIRE 21 COMPORTE DEUX RESONATEURS 2, 3 OPPOSES VIBRANT LONGITUDINALEMENT ET UN COUPLEUR 9 VIBRANT LONGITUDINALEMENT CONNECTE ENTRE LES FACES EN VIS-A-VIS RESPECTIVES DES DEUX RESONATEURS. LE DIAMETRE D DU COUPLEUR EST DEFINI PAR LA FORMULE:(CF DESSIN DANS BOPI)L'INVENTION S'APPLIQUE AUX FILTRES ELECTROMECANIQUES NOTAMMENT A LARGE BANDE.