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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 />

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