The 4 cent antenna works perfectly. Two coins with a value of 2 Euro Cent at the end of a coaxial cable form a good antenna.
We tried the same with coins valued at 1 cent and 5 cents. There is always an antenna. The 2 x 2 Cent antenna for 2400 MHz is not calculated and more a randomness based on a PDF. However, you can clearly see that the change in the mechanical arrangement already results in a change in the bandwidth. In the seminars and workshops we put a thin plastic foil over the 4 cent antenna and show that a few micro meters of plastic already cause a jump in the center frequency. In the next slides we will discuss the frequency jump in more detail. Antennas are systems and not components. Antennas change their characteristics in the influence of different parameters like size of the groundplane, holes in the groundplane, material and thickness of the housing and much more. The data sheet is only a guideline but no guarantee for function. Data sheets for antennas usually apply to optimal ground planes without enclosures.
Has this article series piqued your interest? Do you plan your own LPWAN IoT device? Do you plan to deploy IoT devices with embedded antennas? Do you have an IoT prototype and need to optimise the design or minimise the price? If you have answered “YES” to any one of these questions then please do not hesitate to drop an email to harald.naumann (at) lte-modem.com and to ask for a proposal or some engineering services to make your IoT idea a cost-effective reality.