As the key equipment of radar, transmitter has high power density and good heat dissipation effect.With the development of modern radar technology and the continuous progress of power device manufacturing technology, the assembly density and power density of radar transmitter are constantly increasing.Large phased array radar T/R power components, airborne high-power transmitters, fourth-generation solid-state transmitters, and spaceborne T/R components all put forward higher requirements for cooling.Feasible cooling method and excellent cooling effect have become more and more important support for the whole radar with high reliability index.
The influence of temperature on the performance of radar system is very important.Too high and too low temperature will lead to the failure of electronic components, and then make the whole radar equipment failure. In the high-power radar transmitter, the influence of temperature on the device performance is more prominent.
Liquid cooling plate is a cooling method in which the thermal conductivity and specific heat of liquid are relatively large, which can greatly reduce the thermal resistance of each heat exchange link.Liquid cooling has high heat flux, uniform heat load, small temperature gradient and compact structure.
Lori technology after more than 10 years of research and development design, has a very mature liquid cooling cooling technology.
At present, liquid cooling plate can be divided into direct liquid cooling and indirect liquid cooling.Direct liquid cooling can be divided into immersion direct liquid cooling and direct forced liquid cooling;Immersion direct liquid cooling is mainly used for high-power high-voltage devices in the transmitter, such as soaking the cathode of klystron, high-voltage transformer, inductor and silicon pile in the cooling liquid to remove the heat belt.Direct forced liquid cooling is widely used in high-power transmitters, such as klystron collector, tube body, output window, wire package, isolator and anode of orthogonal field tube.Foreign microwave power module (MPM), in order to reduce the volume, reduce the weight and solve the heat dissipation problem of high heat density, also use direct forced liquid cooling.When adopting indirect liquid cooling method, the cooling liquid does not contact with the cooled device, but is made into liquid cold plate and pipeline to take away the heat indirectly. This method is mainly used for high-power solid state components, especially high-power T/R components, and transistor modules.The key technology of transmitter forced liquid cooling system is liquid cooling component and accurate flow distribution.