Dual-Function Triple-Band Heatsink Antenna for Ambient RF and Thermal Energy Harvesting

The Internet of Things (IoT) infrastructure requires billions devices that must ideally be self-powered. Ambient RF and thermal energy have great potential since they are both available continuously throughout the day. An harvester is a rectenna combination receiving antenna rectifier. Thermal harvesters (TEH) typically static type, with fixed hot source at one end cold other. Here, we present transient type TEH generates from diurnal cycle temperature fluctuations. Smart integration achieved by designing to also act as heatsink for TEH. optimized while considering electromagnetic radiation well heat transfer performances. Thus, two simulators, Ansys HFSS Fluent, were employed. operates GSM900, GSM1800, 3G bands simultaneously, measured gains 3.8, 4, 5.3 dB, respectively, which increased ~3–4 dB (radiation efficiency doubled ~40% ~80%) compared flat (with no fins). in form square box where identical rectennas cover four sides. Through field testing, ~250 mV consistently collected any instance ( $6.25 {\mu }\text{W}$ 10 notation="LaTeX">$\text{k}\Omega $ load). Without antenna, average power notation="LaTeX">$13.6 , increases 2.3 times when integrated, highlighting utility this co-design monolithic integration, enhances harvested powers.