asked by
How do you tune the T1 pin of the SR4L049-R with a VNA?


Currently I am in the process of tuning a SR4L049-R antenna on a custom board. I already did some measurements and exported them to Atyune. I can tune the antenne for the appropriate radio bands, but where in the whole process do I include the T1 for tuning?

Steps taken:

  1. calibrating VNA 
  2. removed all matching components, shorted out path to antenna. << also remove inductor on T1?
  3. connected VNA to antenna path 
  4. executed a VNA measurement 
  5. experimenting with tuning in Atyune. 
For example, this could be a result of my matching Atyune based on my measurements. 
But the matching below, doesn't take into account the T1 pin.

Please log in or register to answer this question.

1 Answer

answered by
Hello EH,

Please see my most recent response as to how the T1 component plays into the tuning of the antenna.

On step 2, did you short the path to ground to adjust the electrical delay? This should be done as the electrical delay is transferred to the S1P file and comes up in Aytune. This is very important to help you start in the correct part of the Smith chart.

Best regards,

Geoff S.

Meet the moderators

Yu Kai Yeung

Antenna Engineer at Antenova Yu Kai is an antenna expert with over 10 years of experience in the design and testing of antennas. He has experience helping customers with certification testing, combined with his knowledge of RF measurement procedures.

Raymond Lee

Senior Antenna Engineer at Antenova Raymond has a wealth of experience in RF and antennas across many industry sectors. He has over 20 years of experience in electronics design and manufacturing.


Antennas: The Comparison Guide

Find the perfect antenna for your project