40 results about "Solenoidal magnetic field" patented technology

A linear switch actuator for actuating a movable element within a microwave switch includes a ferromagnetic shield, a coil positioned within, and a movable armature assembly positioned within the coil. The armature assembly is coupled to the movable element and includes a ferromagnetic rod and first and second permanent magnets. The permanent magnets are coupled on either end of the rod and have opposite pole orientations. The armature assembly moves between first and second stroke end positions. When one of the permanent magnets is positioned substantially outside the shield, the magnetic permeance of the armature assembly is maximized, and the armature assembly experiences bi-stable latching between the two stroke end positions. When the coil is energized, the armature assembly moves between these positions due to magnetic interaction between the energized coil and the field associated with the permanent magnets and the solenoid magnetic field associated with the coil which reduces the magnetic permeance associated with said armature assembly.

The invention relates to microwave source devices in the technical field of high-power microwaves and provides a wave-band-cross mechanical frequency modulation relativity back wave oscillator. The wave-band-cross mechanical frequency modulation relativity back wave oscillator comprises a cathode seat, a cathode, an anode outer cylinder, a cut-off neck, a slow wave structure, an inner conductor, a collector, a microwave output and a solenoidal magnetic field. The inner conductor is a cylinder, by adjusting the length of the inner conductor, the frequency of outputting microwaves can be adjusted, and outputting of wave-band-cross microwaves is achieved. An annular groove is formed in the collector, and a supporting rod is fixed on the anode outer cylinder. The wave-band-cross mechanical frequency modulation relativity back wave oscillator has the advantages that by adjusting the length of the inner conductor, frequency can jump between L wavebands and S wavebands, the adjusting manner is simple, the frequency in the wavebands can be adjusted, the bandwidth in the L-waveband frequency is adjusted by 7% or so, and the bandwidth in the S-waveband frequency is adjusted by 2% or so. The outer radius of a slow-wave vane can have a low value, and miniaturization is achieved. A groove structure is reserved at the left end of the collector, reflection of the tail end of the device can be increased, and achieving long-pulse outputting of the wavebands is facilitated.

The present invention relates to a microwave source of the high-power microwave technology field, and provides a relativistic backward-wave oscillator with a collector shaped as a Chinese character chang. The relativistic backward-wave oscillator comprises a cathode base, a cathode, an anode outer cylinder, a cut-off neck, a slow wave structure, a tapered waveguide, a reflector, an output waveguide and a solenoidal magnetic field. The collector shaped as the Chinese character chang is arranged behind the tapered waveguide, a stepped reflection cavity is arranged between the cut-off neck and the slow wave structure, and double extraction cavities are also arranged between the tail end of the slow wave structure and the tapered waveguide. The relativistic backward-wave oscillator of the present invention overcomes the disadvantage that the conventional relativistic backward-wave oscillator is difficult to consider the long output microwave pulse width and the high power conversion efficiency simultaneously, solves the problem that a coaxial extraction structure is easy to generate the plasmas to thereby influence the working efficiency, and realizes the microwave output that the pulse width is greater than 100 ns, the efficiency is greater than 40%, and the power is 6 GW, on the condition of using less slow wave blades. Moreover, a high-power microwave source is compact in structure, and is easy for the repeated frequency operation.

This disclosure provides systems, methods, and apparatus for measuring flow in and around a borehole of an earth formation. A flow measurement device can include a magnet configured to generate a static solenoidal magnetic field with a field intensity that decreases in strength peripherally from the magnet, an electromagnet disposed around the magnet and configured to generate a time varying solenoidal magnetic field, and a radio frequency (RF) coil disposed around the magnet and configured to generate an RF magnetic field transverse to the static solenoidal magnetic field. The flow measurement device can calculate a flow velocity in and around the flow measurement device based upon a signal received by the RF coil.