| Radiation from heatsinks is typically undesirable and should be minimized to reduce electromagnetic interference (EMI). However, in certain applications it can be advantageous to maximize the radiation from a heatsink by using the heatsink as the antenna. For example, high-power RF transmitters require both a heatsink and an antenna. The heatsink is needed to remove the excessive thermal energy generated by the power amplifier, and the antenna is needed to launch the electromagnetic waves. The heatsink antenna combines these two functions into one reducing the total component count in the transmitter and improving antenna performance.;Heatsink antennas were developed at 5.8 GHz and 2.4 GHz using a patch antenna as a mounting and feeding structure. These antennas demonstrated increased radiation efficiency, bandwidth and gain. Parametric studies were performed including fin height, fin thickness and fin orientation to determine the effects on the antenna performance. The orientation of the fins plays a significant role in the behavior of the antenna and must be considered. The radiation patterns can be changed significantly depending fin orientation. Other types of antennas were considered including a pin-fin heatsink antenna, two-finned heatsink antenna, a boxed three-fin heatsink antenna and a cubic antenna. Finally, a heatsink antenna was integrated with a commercial power amplifier to demonstrate the concept. |
