D.V. Nazarov

A new amplifier block is described in the work. The block contains a power amplifier module, a ferrite circulator, a directional coupler, a high-frequency switch, a controlling module, an impulse power source and heat pipes. The main function of the block is power amplification. When a radio impulse signal is put to the block entrance, it is amplified by the power amplifier module and transmitted to the ferrite circulator that guides the signal to an antenna. The band pass filter, that is placed at the exit of the block, is needed for reduction parasitic components of the signal. In case of high VSWR reflected power is transferred through the ferrite circulator to the high-frequency switch. The high-frequency switch transmits the reflected power to a termination, that disperses the reflected power to heat. At the receiving mode the high-frequency switch directs receiving signal to a receiving system. The impulse power source is used for feeding the power amplifier. The controlling module is used for controlling inner parameters of the block. Heating power emitted by the power amplifier and high density of modules location inside block can lead to overheating of radio elements and decreasing block reliability. A new constructive decision, described in the article, is the use of the heat pipes to withdraw heat from the block. According to the article the heat pipe is a sealed container which inner surface is covered with capillary-porous material. Using the heat pipes allowed solving the following problems: draw heat from inaccessible zone of apparatus with high density of heat flow, equable allocation thermal field over apparatus construction, decrease number of overheating, increase efficiency of a heat removal, collecting heat from many energy sources, placed in different zones of apparatus, to joint point of heat removal, where optimal conditions of cooling were created. One of the most important problems of designing radio electronics devices is a provision of optimal thermal conditions. The plot of temperature against thermal power, shows that using heat pipes allows to reduce temperature inside block by 20-25°C in comparison with ordinary radiators. The influence of thermal conditions on no failure operation probability was examined at the work. Due to presented results the following conclusion can be made: reducing temperature inside block by 20-40°C by using heat pipes allows us to reduce rate of failure in three times in comparison with using radiator and increase performance reliability by ten times.