Abstract: A differential pressure driven diaphragm valve with a separated drive chamber and a valve actuation chamber and an assembling method thereof. The valve includes a piston assembly, a drive chamber cylinder body for driving the piston assembly, and a valve actuation chamber valve body for changing a diaphragm piece shape with a diaphragm press block to close a flow passage. A drive rod of the piston assembly is connected to a central connecting portion of the diaphragm by a shaft coupler which is detachably positioned in the diaphragm press block. The central connecting portion of the diaphragm piece establishes a non-rotatable and relatively liftable limiting with the valve body by the valve body and the diaphragm press block. The periphery of the diaphragm piece forms a non-rotatable connection with the valve body. The diaphragm piece forms a relatively rotatable connection with the drive rod by the shaft coupler.

Abstract: A diaphragm switch valve and a method for assembling same, the diaphragm switch valve includes a valve seat having two transverse fluid passages, and a valve body for disconnecting a the two fluid passages by a valve diaphragm and providing an axially collapsible elastic force to the valve diaphragm by an elastic driving structure. The first fluid passage is bent upwards in the valve seat to form a central fluid passage port toward a central axis of valve and toward a lifting diaphragm core corresponding to the valve diaphragm the second fluid passage forms, in the valve seat, a surrounding fluid passage port surrounding the central fluid passage port toward a diaphragm flexure of the valve diaphragm; the valve seat or the lifting diaphragm core has a annular knife-edge respective on the central fluid passage port and the surrounding fluid passage port.

Abstract: A broadband terahertz fourth-harmonic mixer circuit, a mixer and a method wherein the broadband terahertz fourth-harmonic mixer circuit includes a radio frequency signal coupled transmission unit, nonlinear device, local oscillator filter, local oscillator signal coupled transmission unit and intermediate frequency filter unit which are sequentially connected; and further includes a radio frequency input port, local oscillator input port and intermediate frequency output port, where the radio frequency input port is connected to the radio frequency signal coupled transmission unit, the local oscillator input port is connected to the local oscillator signal coupled transmission unit, the intermediate frequency output port is connected to an output end of the intermediate frequency filter unit, and the local oscillator filter is of a two-level cascaded filter structure.

Abstract: A method and system for testing the conversion losses of terahertz mixers capable of eliminating the influence of radio frequency sources includes grouping a mixer to be tested and at least two reference mixers in pairs; in each group, inputting a signal of a preset frequency and a preset power at an intermediate frequency port of a first mixer, and after up-conversion, outputting same to a second mixer to be down-converted, so as to obtain an output power with the frequency same as the preset frequency, and obtain the relationship between a first output power and a first preset power and the losses of two mixers; according to the relationship between the loss of the mixer in each group and the power, obtaining the loss of the mixer to be tested.