Silicon monolithic MM-wave integrated circuit (SIMMWIC) devices mounted up-side-down on a copper heat sink integral with cavity resonator

Silicon monolithic MM-wave integrated circuits (SIMMWIC) used as oscillators in radar system applications in the 60-80 GHz regime are mounted on a heat sink with integrated resonator. The heat sink consists of a thin carrier plate (aluminum nitride (AlN) or copper (Cu)) and and a gold plated copper block with integrated resonator cavity. The resonator cavity is formed by a rectangular cavity milled in the Cu block, terminated on the top by the gold plated carrier plate on top of which a MM-wave emitting integrated coplanar slot-transmitter is mounted up-side-down. The main part of the emitted RF power is radiated through the substrate-perpendicular to the chip plane-the other part is coupled through a slit on the carrier plate into the resonator cavity leading to a higher spectral purity and a stabilization of the oscillating frequency.<
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