The dual-mode double-gap resonator with asymmetrrical strip line on the suspended ceramic substrate
A new dual-mode double-gap resonator on the basis of asymmetrical suspended stripline for miniature klystron type microwave tubes with field emitter arrays (FEA) cathodes was investigated. The resonator has a smaller size and mass when a doublegap capacitive segment of each quasi-lumped resonator consists of two assimmetrical strip conductors on opposite sides of the substrate and both inductive segments are grounded. This resonance circuit has two oscillation modes (anti-phase and in-phase). On the basis of the 3-D modeling found that such oscillatory systems can achieve the excitation of these modes with multiplicity of frequencies to = 2 with a good efficiency of interaction of electrons with microwave fields.
Resonant properties of double-wire suspended stripline resonator
A double-wire stripline resonator on a suspended dielectric substrate is a novel resonant structure, which can be used in miniature microwave filters. The resonator differs in both short length and high Q factor. Resonant frequencies are investigated in this paper. It is proved that the length of a regular double-wire suspended stripline resonator is shorter than a quarter of wavelength
NMR characteristics of intracellular K in the rat salivary gland: a 39K NMR study using double-quantum filtering.
Intracellular K of the perfused rat mandibular salivary gland was measured by 39K NMR spectroscopy at 8.45 T. Multiple-quantum NMR arising from multiple-exponential decay was used to eliminate the resonance due to extracellular K in the perfused gland at 25 degrees C. The resonance due to intracellular K consisted of two Lorentzian signals stemming from the [spin 1/2 to -1/2] coherence (sharp resonance) and the [spin -1/2 to -3/2], [spin 3/2 to 1/2] coherences (broad resonance). The transverse relaxation time (T2) corresponding to the [spin 1/2 to -1/2] coherence was ca. 2.5 ms, and that corresponding to the [spin -1/2 to -3/2], [spin 3/2 to 1/2] coherences was ca. 0.4 ms. The relaxation time of the double-quantum coherence of rank 3 (originating from product operators like Ix2Iz) was determined to be ca. 0.2 ms. These results suggest the possibility of the presence of a single homogeneous population of intracellular K with a correlation time of ca. 2.5 x 10(-8) s and a quadrupolar coupling constant of ca. 1.4 MHz.