Abstract: A monolithic thin film resonator, lattice filter including spaced apart strips of a conductive film positioned on a substrate so as to define a first set of I/O terminals, a layer of piezoelectric material positioned on the conductive film, and spaced apart conductive strips of a conductive film positioned on the piezoelectric layer orthogonal to the first strips to form cross-over areas, each defining a thin film resonator and a second set of I/O terminals. A plurality of portions of a dielectric film are positioned on selected cross-over areas to mass load the thin film resonators so as to lower the resonant frequency.

Abstract: A filter (200) having an input terminal (208), an output terminal (209), and a common terminal (210) includes two impedance inverters (201,202) and a first resonator (203) that is operable at a resonant frequency. Each impedance inverter (201, 202) is coupled to the common terminal (210) at a common node (223) and includes a corresponding input node (221,225) and output node (222, 226). The input node (221) of the first impedance inverter (201) is coupled to the input terminal (208). The input node (225) of the second impedance inverter (202) is coupled to the output node (222) of the first impedance inverter (201), while the output node (226) of the second impedance inverter (202) is coupled (e.g., via a second resonator (205)) to the output terminal (209). The first resonator (203) is coupled between the input terminal (208) and the output terminal (209).

Abstract: An integrated switch (100) includes a first input port (102), a second input port (112) and an output port (106). The integrated switch (100) comprises a first electronically-tunable integrated capacitor (104) having a control line (108) for selectively coupling the first input port (102) to the output port (106). The switch (100) also includes a second electronically-tunable integrated capacitor (110) having a control line (108) for selectively coupling the second input port (112) to the output port (106).

Abstract: An unbalanced surface acoustic wave (SAW) resonator-filter is achieved by using a predetermined length of unbalanced transmission line to define a ground potential and permit two SAW resonators and such transmission line to function together as an unbalanced filter.

Abstract: An improved crystal notch filter is disclosed with a large passband-to-stopband ratio. The filter has individual sections with discrete crystal devices. In one embodiment as a 55 MHz trap, the filter has a passband from about 50 MHz to about 212 MHz with a 1 KHz stop band about a center frequency that may be tuned by means of a laser-trimmed bridging resistor.

Abstract: A monolithic lattice SAW bandpass filter having low insertion loss and a wide bandwidth range is described herein. Specifically, the bandpass filter includes a monolithic piezoelectric substrate and two dual port SAW device disposed on the substrate and coupled in a full lattice circuit configuration. In a second bandpass filter design the filter includes a monolithic substrate and two sets of dual port SAW devices disposed on the substrate and coupled in a cascaded circuit configuration such that no electrical crossovers occurs on the substrate.

Abstract: A piezoelectric device package consists of a base and a cover which are sealed together to hermetically seal a piezoelectric device such as a quartz crystal therebetween. A recess in the cover receives the quartz crystal. Feedthrough holes in the base, or the cover, or both, which have electrostatic seals formed over them provide a means for making electrical connections with the quartz wafer while still maintaining the hermetic seal.

Abstract: A symmetrical two pole monolithic crystal filter is combined with appropriate value fixed capacitors and cascaded with other similar filter elements to provide a high order filter with symmetrical transmission zeros and low passband ripple. The filter includes a piezoelectric resonating element having first and second opposite sides with first and second pairs of electrodes thereon. A first capacitor is coupled to an electrode of the first pair located on the first side and a second capacitor is coupled to an electrode of the second pair of the electrodes located on the first side. A shunting capacitor is used between the electrodes of the first and second pairs located on the first side. A fourth capacitor is coupled from both of the first and second electrodes located on the second side.