11 results about "Leakage radiation" patented technology

The invention discloses a millimeter wave circular polarization ridge gap waveguide antenna. The waveguide antenna comprises a feed waveguide layer, a waveguide gap layer, a grating lobe suppressor, a polarization converter and a radiation cavity layer which are sequentially stacked from bottom to top. The waveguide antenna adopts an interdigital ridge structure, so that electromagnetic wave leakage radiation can be effectively inhibited, the stability of the working mode of the antenna unit is ensured, and the isolation of the antenna in a large-scale array is enhanced; the feed waveguide layer and the waveguide slot layer are spliced to form the interdigital ridge structure, the production and assembly process is simple, the welding process is omitted, and the production cost is reduced; left-hand circular polarization or right-hand circular polarization can be switched on the polarization converter by changing the orientation of the cross-type gap. By feeding from the two ends of the feed waveguide layer, a dual-circular-polarization working mode can also be realized; by adjusting the size of each slot on the waveguide slot layer, the flexibility of grating lobe suppression can be improved, and the side lobe level of the antenna can be reduced. The invention relates to the technical field of antennas.

The invention relates to the technical field of electromagnetic interference protection, in particular to an electromagnetic interference protection device for GNSS (Global Navigation Satellite System) navigation equipment, which comprises an electromagnetic signal protection isolation structure and a signal collector, the signal collector is arranged in the electromagnetic signal protection isolation structure, and a gap is formed between the signal collector and the electromagnetic signal protection isolation structure; the electromagnetic signal protection isolation structure is arranged at the top of the mobile platform and is farthest from a transmitting antenna of the mobile platform, and the transmitting antenna is the transmitting antenna of the high-power frequency equipment; and a receiving antenna of the mobile platform is arranged in the signal collector. According to the invention, the strong radiation power of an interference signal can be actively absorbed through the wave-absorbing antenna, the leakage radiation power of the interference signal can be passively isolated through the electromagnetic signal protection isolation structure, and the signal collector is also used for actively collecting a weak navigation signal of a satellite, so that the strong interference signal is absorbed and isolated; collecting and amplifying the weak navigation signal; the mobile platform can still receive satellite signals and realize accurate navigation in a strong interference environment.

The invention relates to a double-layer multi-leaf collimator with a self-monitoring function and a using method thereof, and belongs to the technical field of radiotherapy equipment.The double-layer multi-leaf collimator is subjected to multiple times of image acquisition through an image acquisition assembly, the actual position and the preset position of a grating leaf are judged based on the self-monitoring function of a backlight path, and the real position of the grating leaf is determined. The leakage emission rate is further reduced, the dynamic intensity modulation capability is improved, an external sensor is not needed, and the system integration degree is high. Micron-scale control of the grating blade position is realized through optical feedback, and the high-precision treatment requirement is met. By utilizing the mutual shielding effect of the two layers of blades, the effects of simplifying the accelerator layout, reducing leakage radiation and improving the projection resolution of the blades are achieved, the device is mainly used for stereotactic radiotherapy of tumors and other adaptations, blade position errors caused by motor faults and mechanical faults of a multi-blade collimator are avoided, and the reliability of the device is improved. And irradiation errors are further avoided.

A method for identifying the cessation of a rotatable microwave distribution device (8) of a household microwave appliance (1), wherein during the feeding of microwaves (MW) into the cooking chamber (2) of the household microwave appliance (1), at least one microwave leakage radiation (LS) is monitored for the presence of angle-related repetitive fluctuations (Max1, Min, Max2), and if the absence of such fluctuations (Max1, Min, Max2) is identified, at least one action is triggered. A household microwave appliance (1) comprises: a cooking chamber (2), a microwave generator (5) for generating microwaves (MW), at least one rotatable microwave distribution device (8) for changing the field distribution of microwaves (MW) fed into the cooking chamber (2), at least one leakage radiation measuring device (11) for measuring microwave leakage radiation (LS), and a data processing device (10) configured to perform the method. The invention can be particularly advantageously applied to microwave cooking appliances, especially ovens with microwave functionality.

The utility model relates to an irradiation field scattered radiation measuring device for boron neutron capture therapy equipment, which comprises a horizontal support rod provided with scales; the adjustable supports are arranged at intervals and used for supporting the horizontal supporting rods and adjusting the heights of the horizontal supporting rods; and the multiple groups of measuring assemblies are detachably clamped on the horizontal supporting rod, and the positions of the measuring assemblies clamped on the horizontal supporting rod can be adjusted according to measurement requirements so as to measure the field scattered radiation dose of the boron neutron capture therapy equipment. According to the scheme of the utility model, the horizontal supporting rod and the measuring assemblies clamped on the horizontal supporting rod can be adjusted to a proper height through the plurality of adjustable brackets, and then each group of measuring assemblies can be accurately adjusted to related positions according to the scales on the horizontal supporting rod according to measurement requirements so as to accurately measure the scattered radiation dose. The leakage radiation level of the boron neutron capture therapy equipment is scientifically controlled, normal tissues are prevented from receiving unnecessary excessive radiation, and the safety of patients is protected.

In a method for detecting spark-overs in a treatment compartment of a household microwave appliance during a microwave treatment process, a setting value of a microwave operating parameter can be varied during the microwave treatment process. During the microwave treatment process, measurement values of a leakage radiation are measured several times in succession under same setting values of the microwave operating parameter, and a spark-over is detected when a fluctuation range of the measurement values achieves or exceeds a predetermined fluctuation range.

In a method for detecting a standstill of a rotatable microwave distribution apparatus of a household microwave appliance, while microwaves are being supplied into a cooking compartment of the household microwave appliance, a microwave leakage radiation for angle-dependent recurring fluctuations is monitored and an action in the absence of such fluctuations being detected.

A multi-leaf collimator and a radiotherapy machine are disclosed. In one embodiment, the end face of the blade tip of the multi-leaf collimator is not a complete plane or curved surface, but is distributed with a plurality of protrusions and depressions. When the blades are relatively closed, the protrusions and depressions at the tips of the two blades just fit together, so as to completely avoid the problems of end leakage radiation, end collision and dose gradient region.

The present application relates to the technical field of nuclear power plant radiation monitoring, and particularly relates to a primary loop pressure boundary leakage radiation monitoring device and a monitoring method thereof. 18 F has a long half-life, positron annihilation and other characteristics, and the gamma-gamma digital coincidence measurement technology is applied to the primary loop pressure boundary leakage monitoring, quantitative monitoring of the primary loop pressure boundary leakage rate is realized, the anti-interference capability of the system is improved, the detection lower limit of the system is reduced, and the system is miniaturized to a certain extent.

A method for identifying arcing within a processing chamber (2) of a household microwave appliance (1) during a microwave processing procedure, wherein the setpoint of at least one microwave operating parameter is varied during the method, wherein a measured value (LM) of leakage radiation is measured multiple times sequentially at the same setpoint of the at least one microwave operating parameter during the microwave processing procedure, and an arcing is identified when the fluctuation range (LMS) of the measured value (LM) measured at the same setpoint reaches or exceeds a predetermined fluctuation range (LMS thr). A household microwave appliance (1) has a microwave generator (5) for generating microwaves, a processing chamber (2) capable of being loaded by the generated microwaves, microwave detection devices (10, 11) for measuring microwave leakage radiation escaping from the processing chamber (2), and a data processing device (10) for identifying arcing by evaluating the microwave leakage radiation (LM) measured by the microwave leakage detection devices (10, 11), wherein the household microwave appliance (1) is configured to perform the method. This invention can be particularly advantageously applied to stand-alone microwave devices and ovens with microwave functionality, especially when the microwave detection device is equipped with a sniffing circuit.

This invention discloses a surface wave antenna system integrated into a tilted vehicle windshield, comprising a stacked glass substrate, a parallel plate waveguide, a TEM surface wave excitation structure, a TM0 mode conversion and radiation structure, and a TE0 mode excitation and radiation structure. The TEM mode surface wave is shaped and propagated using a gradient-profile parallel plate waveguide, and TM0 mode conversion and leakage radiation are achieved at a single-sided ground interface. Simultaneously, the reverse current coupling between the upper and lower metal conductors excites large-angle TE0 mode surface wave propagation and radiation in the azimuth plane. This invention achieves wide-angle radiation coverage in both the elevation and azimuth planes, and requires no interconnecting vias, making it suitable for integration into vehicle windshields and application in high-frequency communication scenarios such as V2X.