5 results about "Preselector" patented technology

The invention provides a Q / V frequency band large-scale satellite communication load channel optimization method, which comprises a forward input link and a backward output link, and is characterized in that the forward input link comprises a V frequency band multi-beam antenna feed source array, a plurality of input preselectors, a V frequency band low noise amplifier input switch ring and a V / Ka integrated receiver assembly which are connected in sequence; the output end of the V-band multi-beam antenna feed source array is connected with the input end of the V / Ka integrated receiver assembly through a waveguide. The reverse output link comprises a Ka / Q frequency converter, a Q-band channel filter, a Q-band traveling wave tube amplifier, a change-over switch, a Q-band output duplexer or filter and a Q-band feed beam which are connected in sequence, and the output end of the Ka / Q frequency converter is connected to the input end of the Q-band channel filter through a waveguide; and the output end of the Q-band channel filter is directly connected to the input end of the Q-band traveling wave tube amplifier through the waveguide. Therefore, the method is low in link loss, high in space utilization rate and high in feasibility.

The low-grade fluorite mine dry type preselector comprises a machine shell and a rotating ring, the top end of the machine shell is fixedly connected with symmetrically-arranged pumping and discharging openings, a plurality of sliding grooves arranged in an array mode are formed in the pumping and discharging openings, limiting grooves are formed in the positions, corresponding to the bottom ends of the sliding grooves, of the pumping and discharging openings, and filter screens are slidably connected into the pumping and discharging openings. Limiting grooves are formed in the filter screen, limiting blocks are fixedly connected to the positions, corresponding to the limiting grooves, of the filter screen, a plurality of supporting rods arranged in an array mode are fixedly connected to the top end of the filter screen, inner rods are connected to the supporting rods in a sliding mode, and round blocks are fixedly connected to the top ends of the inner rods. The filter screen is convenient to clean, through holes in the filter screen are prevented from being blocked by dust and impurities, and the filter screen is prevented from being blocked to affect use of the sorting machine.

The invention relates to a monopulse QV capturing and tracking system and method in a frequency conversion mode. The system comprises a Q / V feed antenna, a Q / V feed source, a first V frequency band preselector, a second V frequency band preselector, a first V / Ka receiver, a second V / Ka receiver, a Ka frequency band capturing and tracking receiver, a Ka duplexer and an antenna pointing controller. Downconversion is carried out before the sum and difference signals enter the capturing and tracking receiver, the development difficulty of the capturing and tracking receiver is reduced, and the capturing and tracking receiver can adapt to an antenna with higher working frequency. In order to ensure phase consistency of sum-difference receiving frequency conversion channels, phase consistency control measures such as V / Ka receiving channel local oscillator homology, single machine and waveguide cable layout, temperature control and the like are provided; by adopting an intermittent tracking strategy, the power-up time of the motor winding can be effectively reduced, the service life of the system is prolonged, and the reliability can be improved.

The invention relates to a selector (1) for an on-load tap changer, comprising: a fine selector (2) having at least one selector arm (21, 22); a preselector (4), characterized in that the preselector (4) is actuated via at least one selector arm (21, 22) of the fine selector (2).

The application discloses an automatic level adjusting system and method for pulse signals, and belongs to the technical field of electronic measurement. The system comprises: in the superheterodyne receiving channel, the system draws out a radio frequency signal through a power divider after a preselector, converts the radio frequency signal into a voltage through a detector, compares the voltage with a digital control reference voltage in a subtraction circuit, and obtains a difference signal. The difference signal is collected by an FPGA and it is judged whether the difference signal exceeds a preset range, and if so, an interrupt is triggered. A CPU responds to the interrupt, adjusts the attenuation of an input attenuator and the switch state of a low noise amplifier according to the polarity and amplitude of the difference signal and according to a preset rule, and forms a closed loop feedback control. The application effectively solves the problems of measurement distortion, low efficiency and equipment damage risk caused by improper manual setting when testing unknown pulse signals, realizes adaptive optimization of a dynamic range, and improves the reliability and accuracy of automatic testing.