RFID And NFC Measurements With The Real-Time Spectrum Analyzer

RFID applications are rapidly growing as equipment prices drop and global markets expand. Moreover, many short-range Near Field Communications (NFC) links using similar technology are also enjoying a period of rapid growth. RFID & NFC technologies share a variety of uncommon engineering measurement challenges. Transient signals, bandwidth inefficient modulations, backscattered data, and passive tags all require special measurement capabilities not commonly found in traditional test instruments. The Real-Time Spectrum Analyzer (RTSA) is the first analyzer to offer an RFID specific measurement package in addition to its extraordinary real-time capabilities. This combination provides an outstanding solution for RFID & NFC device characterization. The RTSA can rapidly diagnose development problems, sort out pre-compliance testing performance, and support efficient production of tags and interrogators. In this application note, we examine the challenges of RFID measurements and the RTSA's ability to provide diagnostic insight.

RFID technology has been commercially available for over two decades, tracing its roots back to military Identification Friend or Foe (IFF) systems of the 1940s. Recent advancements in submicron Complementary Metal Oxide Semiconductors (CMOS) promise to make RFID technology ubiquitous. The lure of precision supply chain management, instant checkout transactions, and post sales marketing intelligence, is fueling rapid deployment of the technology.

We begin our discussion with an overview of RFID technology. After reviewing RFID technology, specific signal characteristics and design challenges differentiating RFID data links from other communications systems are examined. The real-time spectrum analyzer's unique capabilities as the first comprehensive RFID test instrument are then highlighted. This leads to a discussion on the specifics of how to make essential RFID measurements by applying the RTSA technology. Some tips for properly validating pre-compliance performance with the RTSA, prior to test certification at an outside laboratory are also given, followed by a brief summary and conclusion.

There are many types of RFID and NFC systems. Throughout this application note a special emphasis is placed on the RFID Electronic Product Code (EPC) formats. The EPC Gen2 format pending adoption by the International Standards Organization (ISO) as ISO 18000-6 Type C embodies many of the typical measurement challenges faced by RFID and NFC engineers. The reader is reminded that the RTSA supports many other RFID and NFC applications. The ISO 18000-6 Type C emphasis is primarily for simplified illustration purposes.