# Presentation: 173857

## FCC RFID Workshop RFID DiscussionsSeptember 7, 2004

*Kevin Powell, Symbol Technologies*

## RFID Market Direction

## The Goal  is Asset Visibility ... Everywhere!

## EPC Standards Glossary

- Class 0 (available):
- Generation 1, protocol 0
- Factory programmed ID
- Class 1 (available):
- Generation 1, protocol 1
- Write Once ID
- UHF Generation 2 (future):
- Single Gen2 protocol
- Variety of memories & features
- First products in 2005

## Readers and Antennas

- AR400 Reader

**High ****Performance Antenna**

**General Purpose Antenna**

- SR400 Reader

## Handheld with RFID

- Supports:

- Same ruggedness and ergonomic as the MC-9000G

**Antenna (front-mounted)**

- and additional electronics add the ability to read and write either EPC Class 0 or Class 1 RFID tags

**Integrated** **wireless networking**

**RFID **

** ****2D bar code **

***“******all in one”***

**1D bar codes **

- &

**simultaneously**

## EPC-Compliant RFID Tags

**Plastic Tag**

**Carton Tag**

**Glass Tag**

**Concrete Tag**

**Plastic Bottle Tag**

**Generic Tag**

- Variety of tags      for different materials                   and applications

**Class 0/0+**

## Basics - RFID System

- A tag ***stores information*** and ***exchanges it*** by radio signal

**Passive RFID***** *****Tag**

**Reader commands the tag & simultaneously listens for responses**

**RF modulator**

**Memory**

**Power recovery**

**Digital logic**

**Radio***** *****Signal***** ***

**RFID Protocols**

**RF demodulator**

**Oscillator**

**All in 10 microwatts!**

## Passive RFID System Design

- Passive Tag Constraints
- Battery-less – RF field powered ONLY, thus:
- Total consumed power < 10 W (10M range), and
- Simple demodulator (amplitude – 1bit/Hz style)
- Simple modulator (1 transistor – square wave out)
- Backscatter (modulated RCS) only Tx method
- Passive Tag Results
- Very wide band response (effective antenna BW) in receiver as well as backscatter(but at low levels)
- Confined to relatively inefficient reader modulation encoding methods (simple tag demod).

## Passive RFID System Design

- Reader Constraints
- Must energize tag (transmit) while in receive mode
- = Receive –50dBm while transmitting +30dBm
- Avoid noise sources
- Reader transmit & receive circuitry
- Other backscatter sources, ie fluorescent lighting
- Reader Results
- Extremely low noise design necessary to properly receive tag signals while transmitter is on.
- Detect and avoid other high power RF devices.
- Shift receiver away from noise sources.

## RFID Frequency Sources

**Reader Tx**

## Passive RFID Trends

- Better tag designs/protocols = lower power

| Year | Tag Dist | Rdr pwr | Tag field | Rdr Rx |
| --- | --- | --- | --- | --- |
| 2000 | 10’ | +30dBm | 600W | -45dBm |
| 2002 | 25’ | +30dBm | 100W | -60dBm |
| 2004 | 50’ | +30dBm | 25W | -75dBm |
| 2006 | 75’ | +30dBm | 11W | -82dBm |
| 2008 | 100’ | +30dBm | 6W | -87dBm |

- Note – Fluorescent interference approx –60dBm

## Gained Knowledge

- Reader signals interfere with tag signals at thousands of feet separation.
- Reader signals interfere with other reader transmissions at less than 100 feet.
- 80-100 dB range between Reader and Tag leads design to a separation of disparate power levels such that:
- Reader signals ONLY contend w/ other readers
- Tag signals ONLY contend with other tags

## Conclusions, Requests

- As technology improves tag distances, the impact of noise (self, and fluorescent) becomes severe; the available technology is near the limit.
- Technology improvement comes on the heels of the ability to remove the tag response from noise.
- Request - allow readers on even channels, tag response on odd channels (or similar) as an optional channel use model.

## Thank You

- Questions?

**?**