Optimizing Miniature Antennas for IoT: A Guide with HFWorks

Planar-Printed Antennas
By Nesrine Selmi | 21/02/2022

The Miniature Antenna Paradox

Cisco forecasts that 500 billion devices will connect to the Internet by 2030, fueling the Internet of Things (IoT) expansion and a demand for miniaturization across devices like wearables and medical equipment. Despite their appeal, miniaturizing antennas present challenges, with higher frequencies like Terahertz offering a solution, albeit with limitations like signal decay and absorption by water.

The Miniature Antenna Simulation

To better design and optimize miniature antennas for IoT terminals, at a lower cost and a faster pace, there is no option but to use antenna simulation software. Tools, like HFWorks, can be instrumental in virtually prototyping such small antennas long before attempting any actual prototyping.  


Top (left) and bottom faces of the IoT antenna model


PCB Antenna with Plastic Casing and Battery

Circuit parameters such as return and insertion losses, resonant frequencies, impedances, and VSWR can readily be computed and optimized over a wide frequency band; antenna parameters such as gain, directivity, efficiency, and radiation pattern can equally be optimized and what-if scenarios investigated.  Below, are some results optimized by HFWorks for a miniature multi-band antenna for the Internet of Small Things:



Return Loss Plots: Variation of the Strip Length L4



Return Loss Plots: Variation of the Slot Length L1


VSWR of the Optimized Antenna Design


Total Efficiency of the Optimized Antenna Design


E-field Distribution on Top(left) and Bottom View at 1.23 GHz


2D Gain Pattern at Phi= 90º (at 1.23 GHz)



3D Gain Pattern at 1.23 GHz


The paradox of miniature antenna design in the expanding universe of the Internet of Things underscores a critical engineering challenge: achieving efficient, small-scale antennas amidst the push for miniaturization. Simulation software like HFWorks emerges as a pivotal solution, enabling the intricate balance of size, efficiency, and performance in antenna development. This approach paves the way for the next generation of compact, yet powerful IoT devices, heralding a future of seamless connectivity.