41results about How to "Reduce frequency difference" patented technology

A surface acoustic wave device, includes: an interdigital transducer serving as an electrode pattern to excite a Rayleigh surface acoustic wave, the interdigital transducer including a comb-tooth-shaped electrode having a plurality of electrode fingers; a piezoelectric substrate on which the interdigital transducer is formed, the piezoelectric substrate being made of a quartz substrate that is cut out at a cut angle represented by an Euler angle representation (φ, θ, Ψ) of (0°, 95°≦θ≦155°, 33°≦|Ψ|≦46°); electrode finger grooves formed between the electrode fingers of the comb-tooth-shaped electrode; and electrode finger bases being quartz portions sandwiched between the electrode finger grooves and having upper surfaces on which the electrode fingers are positioned. The surface acoustic wave device provides an excitation in an upper limit mode of a stop band of the surface acoustic wave.

An ion trap includes an electrode structure, including a first and a second opposed mirror electrodes and a central lens therebetween, that produces an electrostatic potential in which ions are confined to trajectories at natural oscillation frequencies, the confining potential being anharmonic. The ion trap also includes an AC excitation source having an excitation frequency f that excites confined ions at a frequency of about twice the natural oscillation frequency of the ions, the AC excitation frequency source preferably being connected to the central lens. In one embodiment, the ion trap includes a scan control that mass selectively reduces a frequency difference between the AC excitation frequency and about twice the natural oscillation frequency of the ions.

The invention provides a frequency demultiplication adjustment method of PLL, applied to an embedded system. The method comprises the following steps: obtaining a plurality of corresponding frequencydemultiplication frequency points according to a default frequency demultiplication value of a phase-locked loop; obtaining, by a processor frequency adjustor, a load state of a processor within a predetermined sampling period, and obtaining a target frequency point of the processor according to the load state; determining a frequency range of a virtual frequency point to be added according to theposition of target frequency between the frequency points; performing calculation within the frequency range to obtain equivalent frequency corresponding to a plurality of virtual frequency points; judging whether the frequency of the target frequency point is equal to the equivalent frequency corresponding to the virtual frequency points; if not, switching the processor frequency adjustor to thecorresponding frequency demultiplication frequency point; and adjusting the frequency demultiplication value of the phase-locked loop, so that the phase-locked loop outputs a clock source signal corresponding to the virtual frequency points to the processor. The problems that after the phase-locked loop is fixed, the available frequency points are insufficient and the frequency corresponding to the frequency points has greater difference in the prior art are solved.

A surface acoustic wave device, includes: an interdigital transducer serving as an electrode pattern to excite a Rayleigh surface acoustic wave, the interdigital transducer including a comb-tooth-shaped electrode having a plurality of electrode fingers; a piezoelectric substrate on which the interdigital transducer is formed, the piezoelectric substrate being made of a quartz substrate that is cut out at a cut angle represented by an Euler angle representation (φ, θ, ψ) of (0°, 95°≦θ≦155°, 33°≦|ψ|≦46°); electrode finger grooves formed between the electrode fingers of the comb-tooth-shaped electrode; and electrode finger bases being quartz portions sandwiched between the electrode finger grooves and having upper surfaces on which the electrode fingers are positioned. The surface acoustic wave device provides an excitation in an upper limit mode of a stop band of the surface acoustic wave.