Written By Dr. Dan Dobkin with an Introduction by Louis Sirico

Introduction

This article is from one of the most in-depth technical references I've ever read. It is chapter 5 from “The RF in RFID: Passive UHF RFID in Practice” written by Dr. Daniel M Dobkin printed with permission from Newnes, a division of Elsevier. Copyright 2008.

I had the pleasure of working with Dan for over a year in contributing content for the RFID Essentials suite of e-learning courses developed by RFID Revolution and he created the YouTag Virtual workshops, which you can find more information about here. I also had the pleasure of interviewing Dr. Dobkin for the premier episode of The RFID Network Cable TV Series where he explained how improbable it is to track a passive RFID tag from satellite. The video is below and is very funny regardless of your technical level. Anyone that spends more than a few minutes with Dan will quickly realize he knows a lot about the RF in RFID. Dan also has a PhD in Physics from Stanford. After reading this chapter, you will understand why we consider Dan a subject matter expert and trusted adviser in our community.

Here is the situation my team faced: A large retailer in the Southwest wants to track items as they move between the sales floor and storeroom. To solve this challenge we had to answer a very practical question, "How do we know if something is coming or going?"