**Abbreviations**


*Planar Antenna Design for Internet of Things Applications DOI: http://dx.doi.org/10.5772/intechopen.92456*

*Advanced Radio Frequency Antennas for Modern Communication and Medical Systems*

**Figure 11** shows the comparison between simulated and measured results of wideband planar foldable and non-foldable antennas. **Figure 11(a)** shows the simulated and measured results of the fabricated foldable antenna which shows that the simulated and measured results are close to each other with the bandwidth of 76% from 1.3 to 2.9 GHz. This range covers the applications in GPS, the 2.4 GHz ISM band, and the general 3GPP WCDMA bands and LTE bands. **Figure 11(b)** shows the simulated and measured results with L equal to 36 and 41 mm (same width of W = 25 mm). Simulated and measured results show that they are close to each other with the bandwidth of 76% from 1.35 to 2.75 GHz, which is little worse than the foldable design in **Figure 11(a)**. The maximum gain of the non-foldable is between

The architecture of the PIFA on PCB with meandering line was shown. The measurement results of return loss and gain performances shown that it has better performances compared to the dielectric antennas as well as without any extra matching components. When only single communication technology is used in IoT product, PIFA is recommended. Using meandering line can reduce the antenna size as well as keeping the performance. PIFA design, therefore, is suitable for ISM band and other IoT applications. In the product utilizing numbers of communication technologies at same times, one wideband antenna integrated in the product is more suitable. Both foldable and non-foldable wideband structures, therefore, were proposed and fabricated for their different uses in IoT applications. Both measurement results of two structures show more than 65% in bandwidth. Their operating frequency covers IoT applications in GPS, the 2.4 GHz ISM band, and the common 3GPP WCDMA and LTE bands. And the foldable structure has advantage of wear-

During the design process, the type of antenna is firstly confirmed and then the key parameters such as frequency and size need to be determined. Simulation software and measurement equipment are important tools to verify its performance and further design iterations may be required for fine-tuning the performance.

**60**

2.5 and 3.5 dBi.

**5. Conclusion**

able applications.

**Abbreviations**

IoT Internet of Things

OTA over-the-air EM electromagnetic

BLE bluetooth low energy PIFA printed inverted-F antenna PCB printed circuit board

VNA vector network analyzer GPS global positioning system

LTE long-term evolution

ISM industrial, scientific, and medical

WCDMA wideband code division multiple access

3GPP 3rd generation partnership project
