BLOCKING READER: DESIGN AND IMPLEMENTATION OF A ...
BLOCKING READER: DESIGN AND IMPLEMENTATION OF A ...
BLOCKING READER: DESIGN AND IMPLEMENTATION OF A ...
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
5.3.2 Duo-PIC separate TX-RX uni-antenna design<br />
The Duo-PIC separate TX-RX uni-antenna design is an improvement over the<br />
Duo-PIC separate TX-RX design. Considering the advantages and disadvantages the<br />
Duo-PIC separate TX-RX design can be improved. The Duo-PIC separate TX-RX<br />
uni-antenna design is as shown in the Figure 5.3. Architecture of Duo-PIC separate<br />
TX-RX uni-antenna design uses a circulator which can eliminate the problem of<br />
isolation of two antennas. Further more the impedance matching circuit can be<br />
clubbed to single circuit reducing the cost of the design.<br />
This circuit will also have other disadvantages adding to the Duo-PIC separate<br />
TX-RX design like<br />
• The design of the circulator for UHF frequencies is bit difficult.<br />
• Cost of the circulator increases design cost.<br />
• Using one antenna reduces the power transmitted to passive tags.<br />
The Table 5.2 shows list of components and its costs. Here you can see the cost<br />
of the circulator is potentially increases the cost of the overall design. The total cost<br />
of this design considering we use this components is $77.71.<br />
Figure 5.3. Architecture of Duo-PIC separate TX-RX uni-antenna design.<br />
48