Folding high frequency substrate for interference mitigation in active antennas

Printed circuit board antennas are often designed to incorporate active elements such as high power amplifiers in order to boost the EIRP of the antenna [1]. Active devices however generate heat. Thus it becomes necessary to employ cooling mechanisms to ensure proper operation of the active antenna. For most applications heat sinks are used for cooling. The drawback of using heat sinks however is that its fins are metallic, which can potentially lead to interference with the radiation pattern. A possible active array implementation is shown in Figure 1 [2]. This paper discusses a novel implementation of conformal antennas, whereby the high frequency substrate is folded, to reduce any unwanted coupling between the radiating elements and the heatsink fins.