Cavity resonance suppression using discrete thermal pedestals in active electronically scanned array

An AESA (Active Electronically Scanned Array), comprising:

• a PCB (Printed Circuit Board) substrate having an obverse surface;
• TRMs (Transmit/Receive Modules) disposed on the obverse surface;
• thermal pedestals wherein each thermal pedestal comprises a wall, having a wall height, comprising wall surfaces and one of the wall surfaces being a contact surface;
• a TIM (Thermal Interface Material), having a TIM height, disposed between a respective contact surface of the thermal pedestals and the obverse surface;
• and
• a heat sink comprising fins,
• wherein the thermal pedestals are discrete with respect to one another,
• the contact surfaces of the thermal pedestals are interspersed about the TRMs,
• the thermal pedestals do not contact the TRMs,
• the TIM is electrically and thermally conductive,
• the wall height plus the TIM height is sufficient to suppress resonances of the TRMs below a frequency greater than Tx and Rx frequency bands of the TRMs,
• the fins extend from a first surface of the heat sink and the thermal pedestals extend from a second surface of the heat sink different than the first surface of the heat sink,
• the heat sink, the fins and the thermal pedestals are of a unitary, one-piece construction, and
• an upper limit of the Tx and Rx frequency bands of the TRMs is less than or equal to 14.5 GHz with a scan angle θ from 0° to 45° and a φ scan angle from 0°≤φ≤360°.