Occasionally I come across individuals who have been in the industry a very long time, and have become great experts in their field, often ending up working as independent consultants. Bruce Carsten is one of them. He even has a grey beard, at least on the probably quite out of date photo on his website. Ancient RF experts were once referred to as “grey beards”, back in the days when it was more wizardry than the modern CAD driven engineering of today. The gems of knowledge that attracted my attention were Bruce’s work on inductor and transformer design. Some excellent papers of his can be found on the Micrometals website. Happy reading.