Abstract: A motor-driven single-seed-ejection sowing device includes a housing, a seed metering roller, a seed brush, a seed metering mechanism and a power mechanism. The housing includes a power compartment and a seed compartment. The surface of the seed metering roller is provided with seed grooves having spaces for accommodating a single seed. The seed metering mechanism includes a spring, a striking tube, a piston and the piston tube. The piston and the piston tube are arranged for axial movement inside the striking tube. The power mechanism includes a control unit and a drive unit. The control unit includes the motor, the drive panel, the Hall sensor and the magnet. The magnet is set on the striking tube. The Hall sensor and the drive panel are connected to the motor, and the motor drives the seed metering roller and seed metering mechanism by the drive unit.

Abstract: A motor-driven single-seed-ejection sowing device includes a housing, a seed metering roller, a seed brush, a seed metering mechanism and a power mechanism. The housing includes a power compartment and a seed compartment. The surface of the seed metering roller includes seed grooves having spaces for accommodating a single seed. The seed metering mechanism includes a spring, a striking tube, a piston and the piston tube. The piston and the piston tube are arranged for axial movement inside the striking tube. The power mechanism includes a control unit and a drive unit. The control unit includes the motor, the drive panel, the Hall sensor and the magnet. The magnet is set on the striking tube. The Hall sensor and the drive panel are connected to the motor, and the motor drives the seed metering roller and seed metering mechanism by the drive unit.

Abstract: A device and method of testing the dual-frequency nonlinear vector network parameters. In view of the challenge of the nonlinear behavioral model characterization of the microwave device components, and the current situation of the nonlinear vector network parameter testing, the disclosed device and method of testing the dual-frequency nonlinear vector network parameters redefines the nonlinear model parameters of the nonlinear device components, gives the definition of the test parameter (W-parameter), solves the challenges of the dual-frequency nonlinear behavioral model characterization and testing for the microwave device components, and makes it more convenient to measure the nonlinear characteristics of the mixer, amplifier and passive device components.

Abstract: A device and method of testing the dual-frequency nonlinear vector network parameters. In view of the challenge of the nonlinear behavioral model characterization of the microwave device components, and the current situation of the nonlinear vector network parameter testing, the disclosed device and method of testing the dual-frequency nonlinear vector network parameters redefines the nonlinear model parameters of the nonlinear device components, gives the definition of the test parameter (W-parameter), solves the challenges of the dual-frequency nonlinear behavioral model characterization and testing for the microwave device components, and makes it more convenient to measure the nonlinear characteristics of the mixer, amplifier and passive device components.