Patent classifications
H03H9/02275
One-port surface elastic wave resonator on high permittivity substrate
A surface elastic wave resonator comprises a piezoelectric material to propagate the surface elastic waves and a transducer inserted between a pair of reflectors comprising combs of interdigitated electrodes and having a number Nc of electrodes connected to a hot spot and an acoustic aperture W wherein the relative permittivity of the piezoelectric material is greater than about 15, a product of Nc.Math.W/fa for the transducer being greater than 100 m.Math.MHz.sup.1, where fa is the antiresonance frequency of the resonator. A circuit comprises a load impedance and a resonator according to the invention and having an electrical response manifesting as a peak in the coefficient of reflection S.sub.11 at a frequency of a minimum value of the parameter S.sub.11 that is lower than 10 dB, the antiresonance peak of the resonator being matched to the impedance of the load.
Resonator and method of forming the same
Various embodiments may relate to a resonator. The resonator may include a support including a substrate portion, and a membrane portion extending from the substrate portion over a cavity. The resonator may also include a piezoelectric layer on the membrane portion. The resonator may further include an electrode on the piezoelectric layer. The substrate portion may include dopants of a first conductivity type. The membrane portion may include dopants of a second conductivity type different from the first conductivity type. A ratio of a thickness of the membrane portion to a combined thickness of the electrode and the piezoelectric layer may be above 3:1 for temperature compensation.
MEMS RESONATOR
A MEMS resonator includes a pantograph that is a parallelogram, an oscillator connected to each vertex of the pantograph, and an electrode disposed opposite each oscillator, and forming a capacitor with the oscillator. A set of the electrodes disposed opposite to a set of the oscillators along an extension direction of a diagonal line of the pantograph that is the parallelogram have applied thereto a voltage differing in phase by 180 from another set of the electrodes disposed opposite to another set of the oscillators along an extension direction of another diagonal line of the pantograph. At least two of the MEMS resonators are connected so as to share one oscillator.