PCB antenna with wider bandwidth

by <a href="http://community.silabs.com/t5/Welcome-and-Announcements/Community-Ranking-System-and-Recognition-Program/m-p/140490#U140490"><font color="#000000"><font size="2">Ninja Employee</font></font> </a> zovida on ‎04-04-2017 10:04 AM

Question

How can I make the frequency bandwidth of PCB antennas wider?

Answer

In some cases/applications the BW of printed antennas might not be sufficient. This article summarizes some design tricks on how to make a printed antenna wider bandwidth.

 

- Increase the board size (e.g. GND plane in the case of monopole-type antennas). Avoid using RF modules that have smaller size than quater-wavelength. Small modules generally have poor antenna gain and narrow bandwidth (due to the high Q factor).

 

- Increase the board thickness. Of course, it's typically limited by design.

 

- Decrease the dielectric constant of the PCB. Select PCB material with low epsilon value. 

 

- Use wider and/or tapered traces in the PCB antenna structure.

 

- Do some tricks in the external antenna matching network. I.e. use more components to do the match; create resonators in the matching network. Also, see Bode-Fano, Youla matching techniques.