DigiKey-eMag-RFDesign and Components-Vol 14

How to select and apply antennas for IoT devices

Figure 5: The ST0224-10-401-A Wi-Fi pc board trace antenna is efficient in both the 2.4 and 5 GHz bands. Image source: Amphenol

antenna is Amphenol’s ST0224- 10-401-A Wi-Fi PC board trace RF antenna. The antenna offers an omnidirectional radiation pattern in the 2.4 to 2.5 GHz and 5.15 to 5.85 GHz bands. The antenna measures 30 x 10 x 0.2 millimeters (mm) and has an impedance of 50 Ω. Its RL is less than -10 decibels (dB) for both frequency ranges, and its peak gain is 2.1 dB relative to isotropic (dBi) in the 2.4 GHz band and 3.1 dBi in the 5 GHz band. Its efficiency is 77 and 71%, respectively (Figure 5). Another option for space- constrained IoT products is a chip antenna. Automated equipment can directly mount this compact component on a PC board. The antenna suits wireless IoT applications based on Bluetooth LE or Wi-Fi. The key advantages of a chip antenna are space savings, reduced manufacturing costs, and a simplified design process.

performance of a chip antenna is influenced by factors such as pc board layout and surrounding components, but advances in antenna technology have resulted in highly efficient devices. Chip antennas suit various applications, from smartphones and tablets to smart home systems and industrial sensors.

An example is Amphenol’s ST0147- 00-011-A, a 2.4 GHz pc board surface mount chip antenna. The antenna offers an omnidirectional radiation pattern in the 2.4 to 2.5 GHz frequency band (Figure 6). The antenna measures 3.05 x 1.6 x 0.55 mm and has an impedance of 50 Ω. Its RL is less than -7 dB, its peak gain is 3.7 dBi, and its average efficiency is 80%.

As described above, the

Figure 6: The ST0147-00-011-A surface mount chip antenna is compact and exhibits an omnidirectional radiation pattern in the XY plane. Image source: Amphenol

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