What makes PCB antenna design special?

In our connected IoT antenna design is more important than ever. IoT devices can be found in any kind of locations. Quite often devices are remote places, far away from communication infrastructure and hard to access. This leads to 3 common characteristics:

1. Selection of PCB laminate

The permittivity of PCB laminate is a critical design parameter of microstrip antennas. Variation can cause severe detuning in narrowband antennas. Low loss laminate should be considered when operating frequency gets higher than 5GHz or if RF signal is routed in the PCB. When you have selected your material, you should not change that without testing.

2. Copy-pasting antenna design

Unlike off-the-self chip antennas, compact PCB antennas cannot be copied to another device expecting a good performance. You should always consider PCB antennas as custom designs even if they are based on an earlier design.

3. 2D structure limitation

When PCB trace antennas are printed into the main PCB, they are 2D structures at the same plane as GND. This limits the volume the antenna has. If the amount of surface area for the antenna is very limited, the lack of 3rd dimension leads PCB trace to have less performance than other antenna types like LDS, flex or stamped metal.

3. Matching components

PCB antenna can be matched to 50ohm with an antenna radiator but that is not the best idea. Antenna matching components allow compensating uncertainties related to PCB material and mechanics that would otherwise lead to a series of prototype rounds. If the antenna is on the main PCB this can be quite expensive and time-consuming. Also, any future change would lead to further prototype rounds while adjustment of matching components can be done to any unit.

PCB antenna can achieve the same performance with the same antenna clearance as surface-mounted chip antennas without the associated component price. However, much more attention needs to be placed on the material and supplier selection and auditing over the entire product lifecycle. Therefore, we do not recommend using microstrip antennas unless you know what you are doing!

Radientum Services for PCB antenna design

We at Radientum can help you with that. First, we evaluate the feasibility to use a PCB antenna, select a location for it and design it using full 3D antenna simulation for the entire product. Once you have a prototype available, we will optimize the matching circuit for optimal printed antenna performance. If you need to later do changes to your product, we are available to do re-optimization.

Contact us now to reduce the BOM cost of your product!



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33720 Tampere, Finland
+358 40 501 3535


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