thermal management of rf and microwave devices

dr. shahriar motakef

president

radio frequency devices are used in communications and radar systems. as the power density of these devices increase, removal of associated large heat fluxes beckons novel thermal management solutions. the starting point in thermal management of rf devices is the transistor design, where modifications to the transistor geometry can have a substantial influence on the maximum junction temperature without any appreciable deterioration in the electronic performance of the transistor. the design choices in terms of arrangement of multiple transistors onto a mmic, and the arrangement of several mmics to form a transmit/receive module need to be optimized both thermally and electronically. furthermore, the thermal load at the board level can be extremely high, requiring liquid cooling. this talk will cover the hierarchy of thermal management issues in rf devices, and will present a suite of possible solutions covering transistor layout, heat spreading, and board-level cooling.