Quartz Filter Crystals with Low Inductance

By exciting a harmonic of the Y′ wave in a -18.5°-rotated X-cut quartz plate, the electrodes of the elementary halfwave sections being electrically connected in parallel, and by choosing for each half-wave section the ratio l
s′
/l
y′
> 1, an appreciable reduction in inductance can be obtained; e.g., tenfold or more. With regard to disturbing frequencies, it will be useful to choose this ratio in the neighborhood of 1.8.