The calibration of the VNA for a PCB with embedded antenna is more difficult. The final antenna with all components except the wireless module should be mounted inside the final enclosure. The wireless module will be replaced by the probe.
Why I wrote the IoT M2M Cookbook
In my more than 20 years working with a manufacturer and in distribution I gave the same hints and recommendations to developers of wireless applications again and again. In May 2012 I made the decision to write the story that I have to tell weekly to customers in a book. The target is to guideline developers from the idea for an IoT / M2M device to a final product with mass production.