where L is the overall inductance of the resonator circuit and C its total capacitance. Several resonator designs have been published in the literature for low frequency EPR spectroscopy and imaging. 149–159 Birdcage and Litz coils (both in NMR and EPR) as well as other structures with distributed inductances and capacitances (known as lumped circuit elements) have been …

The WG resonator is essentially “oversized” for millimeter wavelengths and thus enables the designer to use larger structures. In case of an NRD-guide resonator, the dielectric block may be in the form of a rectangle made of a relatively low permittivity and low-cost dielectric material. Thus, size is not a problem.

A resonator, in this cotext, is any device in which a wave can travel back and forth between reflectors.At frequencies above ∼1 MHz a convenient implementation (Fig. 2) is a plate of piezoelectric material, crystal or ceramic, as the transmission medium for sound waves, with force-free end faces at which the sound waves, with force-free end faces at which the sound …

The resonator must contain a neck connected to the cavity filled with a large volume of fluid. The large volume of fluid acts as the spring, while the neck acts as the mass. For the specific shape of the Helmholtz resonator example used here (see Fig. 24), the natural frequency of a 2-D Helmholtz resonator as given by Mechel (2013) is approximately

2015年1月25日 · The resonator is a zero-level packaged polysilicon free-free resonator operating at 25.6 MHz and exhibiting a Q-factor of 334 with a motional resistance of 5 MΩ when biased at 7 V. In this case, an additional mask is required to protect aluminum pads during metal deposition for device sealing.

The acoustic damping effect provided by a Helmholtz resonator at its resonant frequency depends on the bulk geometry of the resonator. It has been shown [2,37] that the maximum damping occurs by tuning/varying the resonator geometry so that the resonant frequency ω res is close to the oscillation frequency that is to be mitigated in the combustor.

2025年1月15日 · The solidly mounted resonator (SMR) was designed using finite element simulation software, featuring a Bragg reflective layer and a piezoelectric sandwich structure. The Bragg layer was constructed with alternating silicon dioxide and aluminum nitride layers.

2024年12月16日 · Resonator A with the four-ring spoke array and relatively smaller support radius has a Q value up to 91000 in vacuum, resulting in an f × Q product of 2.14 × 10 12, while the resonator B without four-ring spoke array achieves Q value of 16900 Simultaneously, the motional impedance 30.34 kΩ of resonator A is only about one-fifth of that of ...

2017年12月1日 · The theoretical formula for the Helmholtz resonator is (1) f = c 0 2 π S V · l a where f is the resonant frequency, C 0 is the velocity of sound in the air, S is the cross-sectional area of the short tube, V is the volume of the acoustic cavity, and l a is the total length of the short tube, the actual length of the short tube is l. l a is l ...

The most commonly re-entrant cavity resonator used in MRI is the TEM resonator devised by Vaughan et al. [41,61], with subsequent adoption by many other groups [62–71]. As an alternative to the (non-cavity-based) birdcage resonator [40,72] , the TEM resonator has been used for body coil designs at 3 and 4 T, as well as for head and knee coils ...