20-07-2012, 12:09 PM
NFC Short-Range Wireless Technology.
1NEAR FIELD COMMUNICATION.ppt (Size: 469 KB / Downloads: 254)
Introduction
NFC provides unique advantages over other available wireless technologies.
The design includes a near-field transmitter and receiver to send data from one computer to another
Modulation/Demodulation Scheme
Frequency Shift Keying (FSK)
VCO produces a frequency-modulated signal at the transmitter
Phase lock loop demodulates the signal at the receiver.
System Overview
Hardware
Transmitter
PC interface (MAX232A)
Voltage-Controlled Oscillator (POS+25)
Power Amplifier (LM6181)
Loop Antenna
Receiver
Loop Antenna
Amplifier (LM6181)
Phase Lock Loop (NE564)
PC interface (MAX232A)
Difficulties
Small antenna bandwidth made us to revise our original design.
Drift in the frequency of VCO.
Amplifier oscillation
Most significant bit flipping
Benefits & Features
Not restricted to 1-to-1 communication
Multiple devices in a small area can communicate with each other using the same frequency.
Maximum transfer bit rate of 800kbps.
No special software is required.
Operation at a frequency of 13.5 MHz
No ethical concerns due to range
Results
Maximum bit rate of 800kbps
Text communication between two PCs
Transmission range of 30cm
Ability to send a text file between PCs
1NEAR FIELD COMMUNICATION.ppt (Size: 469 KB / Downloads: 254)
Introduction
NFC provides unique advantages over other available wireless technologies.
The design includes a near-field transmitter and receiver to send data from one computer to another
Modulation/Demodulation Scheme
Frequency Shift Keying (FSK)
VCO produces a frequency-modulated signal at the transmitter
Phase lock loop demodulates the signal at the receiver.
System Overview
Hardware
Transmitter
PC interface (MAX232A)
Voltage-Controlled Oscillator (POS+25)
Power Amplifier (LM6181)
Loop Antenna
Receiver
Loop Antenna
Amplifier (LM6181)
Phase Lock Loop (NE564)
PC interface (MAX232A)
Difficulties
Small antenna bandwidth made us to revise our original design.
Drift in the frequency of VCO.
Amplifier oscillation
Most significant bit flipping
Benefits & Features
Not restricted to 1-to-1 communication
Multiple devices in a small area can communicate with each other using the same frequency.
Maximum transfer bit rate of 800kbps.
No special software is required.
Operation at a frequency of 13.5 MHz
No ethical concerns due to range
Results
Maximum bit rate of 800kbps
Text communication between two PCs
Transmission range of 30cm
Ability to send a text file between PCs