Abstract: A high frequency RF gasket is disclosed which provides an electromagnetic seal between a first and second piece of a shielding enclosure. The gasket comprises highly resilient finger projections which are attached to and project out along the perimeter of the first enclosure piece. The relative mating arrangement of the gasket, and first and second enclosure piece is such that a small force imposed on said first enclosure piece is resisted by a much larger resistance force along the longitudinal dimension of the highly resilient finger projections as the fingers engage the second enclosure piece. The larger resistance force causes sufficiently high pressure at the point of contact between the finger projections and the second enclosure piece so that the surface of the second enclosure piece yields to the finger projections.

Abstract: A monolithic crystal filter includes a monolithic crystal filter element, a capacitive network connected in series with the monolithic crystal filter element and a bridging capacitor connected across the monolithic crystal element and the capacitive network. The monolithic crystal filter provides a passband that is symmetrically located about the passband center frequency. The monolithic crystal filter element has two pairs of electrodes that resonate at substantially the same frequency. The resonating frequencies of the electrode pairs are preferably below the passband center frequency. The capacitive circuit raises the resonating frequency of one of the electrode pairs such that the geometric mean of the raised and non-raised electrode-pair frequencies is substantially the same as the passband center frequency. The monolithic crystal filter can be cascaded with one or more similar monolithic crystal filters or monolithic crystal filter elements to obtain greater selectivity.