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What is Active RFID

CuhkRFID Solution
CuhkRFID Middleware
CuhkRFID Application
Semi-Active RFID System (CU-Badge)

CU-Badge system consists of four parts: the badges (transponder), an activator, receivers, and a command center. The badge is usually attached on a personal body or virtually any asset (laptop computers, peripherals, electronic equipment, pallets, inventory items, etc.) to be monitored. The working frequencies are at UHF Band from 920MHz to 926MHz. The wake-up range is up to 3 meters. Once a badge is activated by the activator working in the UHF band, it will transmit its ID and other information periodically according to our protocol to a receiver. The collected ID and other information will be sent to the control center. Any authorized monitors can get useful information from the command center. Our system can work in a multi-badge and multi-receiver environment, the number and the locations of activator and receivers can be varied according to the installation requirements.

    System specification:


  • Work frequency:           925MHz
  • Transmitted Power:       27dBm
  • Antenna gain:                ≥6dBi


  • Minimum power needed to active badge: -30dBm
  • Receiving/transmitting Frequencies:    926Mhz / 920Mhz
  • Transmitting Power:                 -10dBm
  • Working current in transmitting mode  <12mA, 3V
  • Current in sleep mode:                        <5uA, 3V



  • Sensitivity: -95dBm(BER=0.001)
  • Antenna:   Sector antenna
  • Detecting range:    > 40 meters
  • Interface with control center: RS232, Ethernet, or WLAN

Communication data rate and code:

  • Data rate: 38.4 kbps
  • T/R mode:  synchronous mode
  • Data code: Manchester
  • Modulation model:   FSK  (frequency deviation 100Khz)
  • Access method:      Time Slot ALOHA
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