What factor is responsible for the range of RFID?

I want to know on what factor does the range of RFID depend?
also i want to start the project on RFID and i need the maximum range so can anyone tell me the maximum achievable range for active and passive tags with detailed information...

Read range is defined as a maximum ommunication distance between the reader and tag. The read range of typical passive RFID products varies from about 1 inch to 1 meter, depending on system configuration.
The read range of an RFID device is, in general,affected by the following parameters:
a) Operating frequency and performance of
antenna coils
b) Q of antenna and tuning circuit
c) Antenna orientation
d) Excitation current and voltage
e) Sensitivity of receiver
f) Coding (or modulation) and decoding (or
demodulation) algorithm
g) Number of data bits and detection
(interpretation) algorithm
h) Condition of operating environment (metallic,electrical noise), etc.


With a given operating frequency, the above conditions (a – c) are related to the antenna configuration and tuning circuit. The conditions (d – e) are determined by a circuit topology of the reader. The condition (f) is called the communication protocol of the device, and (g) is related to a firmware program for data interpretation.

Assuming the device is operating under a given condition, the read range of the device is largely affected by the performance of the antenna coil. It is
always true that a longer read range is expected with the larger size of the antenna.

Hi,

You have different kind of passive RFID card all based on different technology.

You have PROXIMITY CARDS for 125 KHz and 13.56 MHz based on ISO14443 max distance : 4 upto 10 cm (MIFARE 13.56 MHz)
You also have VISINITY CARDS for 13.56 MHz based on ISO15693 upto 1 Meter MAX.
You also have 914 MHz and 868 MHz cards that can work on distances of 10 meters or more !.. They are also passive cards.

regards,

Paul.

i used caliso based on ISO15693 they claming 1 meter max but i got only 10cm

The nex documents contains the whole information you need when you are starting with RFID. Basics and advanced information.

UHF ranging from 860-930MHz (ISO/IEC 18000-6) has the higer range!

Regards!

thx for your information

^-^

Is it possible to design RFID with 2000m range? How? Anyone please....

2Km range in RFID? Umm..... Not really! (not even UHF to the best of my knowledge).