40 results about "Microwave propagation" patented technology

A radar level gauge system, for determining a filling level of a product contained in a tank, comprising a transceiver for generating, transmitting and receiving electromagnetic signals; an antenna arranged to direct transmitted electromagnetic signals towards a surface of the product contained in the tank, and to return reflected electromagnetic signals resulting from reflections at impedance transitions encountered by the transmitted electromagnetic signals back to the transceiver; and a hollow waveguide connecting the transceiver and the antenna for guiding the electromagnetic signals therebetween. A sealing member is arranged to seal the waveguide to prevent fluid from passing into the waveguide from an interior of the tank; and the radar level gauge system further comprises processing circuitry connected to the transceiver and configured to determine the filling level based on the reflected electromagnetic signals. The radar level gauge system further comprises a leak indication member being movably arranged inside the hollow waveguide in such a way that a force resulting from leakage of the fluid at the sealing member causes a movement of the leak indication member when acting thereon; and the hollow waveguide is configured in such a way that the movement of the leak indication member causes a change in at least one microwave propagation characteristic of the hollow waveguide.

A plasma generator is provided which includes: a microwave generation portion which generates a microwave; a wave guide for propagating the microwave; a plurality of plasma generation nozzles which are attached to the wave guide so as to be apart from each other in the direction where the microwave is propagated, receive the microwave, and generate and emit a plasmatic gas based on the energy of this microwave; and a plurality of stabs which correspond to a part or the whole part of the plasma generation nozzles and are each disposed in the wave guide so as to lie in a rear position a predetermined distance apart from each other in the direction where the microwave is propagated.

An apparatus providing uniform microwave processing of products especially those that are likely to absorb microwave energy such as meat and the like. The apparatus uses at least a pair of complimentary processing waveguides. The waveguides are offset along at least one axis thereof so that the energy coupled to the product when traveling through a first waveguide section is presented with a complimentary or mirror image of the field variation applied to the product when traveling in the second waveguide. Energy may be fed to the elongated waveguides through a broad open wall or a wall having narrow openings. Coupling values can therefore be adjusted to transfer a higher percentage of energy in the feeder waveguide as microwaves propagate but then are diminished by a previous coupling section.

The invention relates to an ultra-wideband breast tumor imaging method based on magnetic resonance image compensation. The method comprises the following steps of based on a MRI slice atlas based on breasts, constructing a three-dimensional discrete breast model of a gland; modeling a gland structure and approximating structures of gland tissues in the breasts into an elliptic cone shape; using spatial coordinate transformation and ''righting'' an elliptic cone to an auxiliary coordinate system; creating an isosceles triangle area in a plane projection area of the elliptic cone, carrying out a finite element on the area and determining an elliptic cone surface capable of best describing a change trend of a rough gland surface; and carrying out microwave propagation time error estimation and accurate imaging. In the invention, ultra-wideband breast tumor imaging can be accurately performed.

The invention discloses a bridge dynamic deflection detection method and device based on microwave interference. The method includes the steps: S1 acquiring geometrical characteristic parameters of a microwave interference detection system for a bridge to be detected in the detection process, and acquiring atmospheric dry temperature, atmospheric steam partial pressure and atmospheric dry air partial pressure in detection; S2 calculating an atmospheric refraction index in detection according to the atmospheric dry temperature, the atmospheric steam partial pressure and the atmospheric dry air partial pressure; S3 calculating dynamic deflection of the bridge in detection by a bridge dynamic deflection correction model according to the atmospheric refraction index and the geometrical characteristic parameters. According to the method, the influence of the atmospheric dry temperature, the atmospheric steam partial pressure and the atmospheric dry air partial pressure on the microwave propagation process is taken into consideration, the influence of environmental factors such as temperature, humidity and atmospheric pressure on ground microwave interference detection precision due to season and time difference is avoided, and dynamic deflection detection precision of the bridge is improved.

The invention discloses a microwave short circuit ring comprising a hollow chamber, wherein N grooves are formed on the inner wall of the chamber; N is an integer greater than or equal to 1; when N is greater than or equal to 2, the distance between two adjacent grooves is greater than one half of a microwave wavelength and less than the wavelength of two microwaves; the width of the groove in the microwave propagation direction is one quarter of the microwave wavelength and the tolerance of the width is +/-1 mm; and the depth of the groove is a multiple of one quarter of the microwave wavelength and the tolerance of the depth is +/-2 mm. The microwave short circuit ring has the following beneficial effects that the dose of microwave leakage at the inlet and outlet of a rubber vulcanizing apparatus can be quickly attenuated to be below 30 mu W/cm so that operating personnel can conveniently and freely work by approaching the rubber vulcanizing apparatus; the potential safety hazard is eliminated and the labor productivity is improved; the length of the short circuit ring is one third of the length of the previous short circuit ring; and the equipment manufacture and use costs are reduced.

The invention relates to a lithium niobate electrooptical modulator, in particular to a low half-wave voltage lithium niobate electrooptical modulator, and belongs to the technical field of lithium niobate electrooptical modulators. According to the lithium niobate electrooptical modulator, a travelling wave electrode and a direct current bias electrode are combined into one, it is achieved that only direct current voltage is loaded on a central electrode of the travelling wave electrode through a capacitor of a match circuit, and carrying out direct current modulation is ensured. In addition,an access high frequency property of the capacitor is utilized, microwave propagation is not influenced, and high speed modulation of the modulator is ensured. The device integration is improved, andunder the circumstances of not changing length of a chip and whole size of the modulator, the electrode length of the chip is greatly increased, therefore direct current half-wave voltage and microwave half-wave voltage of the modulator are greatly reduced.

A flat aperture-coupled antenna with a multilayer structure is disclosed. A rear side of the antenna comprises a metal reflector device including a hollow structure (3, 5) with separate box-like compartments, located in registry with radiating patches, corresponding pairs of orthogonal slots and feed elements, whereby microwave propagation within the hollow metal structure is substantially interrupted and any mutual coupling between the orthogonal slots is avoided.

The invention relates to an experimental device and method for microwave frequency attenuation and red-shift with propagation distance based on a Chen Shouyuan effect. The experimental device comprises a signal generating module, a microwave propagation channel and a signal detecting module; wherein the signal generating module is used for generating a microwave with set frequency and amplitude; the microwave reaches the signal detecting module through the microwave propagation channel; the signal detecting module observes the attenuation of the microwave frequency based on the propagation distance by measuring the frequency of the microwave; and the sound source position where the signal generating module generates the microwave, and the measuring point position of the microwave propagation channel and the signal detecting module remain relatively stationary.

The microwave plasma generator is applied to transmission of electromagnetic field into plasma. The invention consists of the fact that the guiding part (3) has two outputs (4, 4′) between which an input (2) of microwave is placed generated from the microwave power source (5). The input (2) is in the distance (A) from the separation (10) of the first output (4) and in the distance (B) from the separation (10′) of the second output (4′) while the absolute value of the difference of the distances A-B or B-A equals λ/2 where λ is the wave length of the microwave and distances A and B correspond to the trajectory of microwave propagation. A microwave plasma generator including microwave power source (magnetron) (5) is connected to the input (2) of the guiding part (3) of the applicator (1)