RACE RESULT RR10 UHF Reader Instructions
- June 5, 2024
- RACE RESULT
Table of Contents
RACE RESULT RR10 UHF Reader
Functional Description
Purpose: UHF RFID Reader for sports time keeping. This device consists of a
UHF RFID Reader, a battery, and communication interfaces. It’s purpose is to
capture UHF transponders worn by participants of a sporting event and transmit
its id, location and time stamp to a remote server. The system consists of two
main parts, a reader and ID tags. The reader interrogates the tags that are
attached to participants in the field created by the reader. Theory of
Operation: The tags derive their power from the RF energy of the reader
signal. They are not internally powered. Signaling from reader to tag is
accomplished by ASK. Signaling from tag to reader is accomplished through
antenna backscatter. The tag momentarily shorts its antenna terminals, which
causes the transmitted power that was being absorbed into the tag to reflect
back off its antenna. The receiver senses this reflected signal. Transmitter:
The transmitter produces a CW signal that is modulated. In the transmitter,
the phase-locked loop output is amplified and then modulated by an RF mixer
that is controlled by the microprocessor. The RF signal then passes through
the final amplifier stage and low pass filter and then transmitted from the TX
antenna. Receiver: The sensed backscatter signal from the RX antenna is
combined with a carrier cancellation signal (derived from the TX path) and
amplified by a LNA and then quadrature down-converted by mixing using an LO
tapped from the TX path.
The two baseband signals are amplified, filtered and AD converted as an input
signal to the microprocessor. Antenna: The device has a bistatic antenna setup
consisting of two integrated patch antennas with 6dBi gain. Power: The power
conducted to the antenna is set to below 30 dBm. With an antenna gain of 6dBi,
the effective isotropic radiated power is rated at less than 36 dBm (4 Watts).
Modulated Signal Bandwidth: The 20dB bandwidth of the modulated signal is less
than 500 kHz. Frequency Hopping Configuration: There are 51 hopping channels
with center frequencies located at 5