MOS parallel to antenna - antenna clamp, antenna modulator
时间：04-04
整理：3721RD
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Hi,
I would like to understand the following thing: in RFID passive circuits there are MOS transistors, which work as a clamp or a modulator. These transistors are in parallel to antenna. Drain is connected to one end of the antenna and source is connected to the other end. The example can be found here:
../imgqa/eboard/Antenna/rf-4v1g3ohmxng.jpg
The question is: where is the body of the MOS transistor connected?
Nodes on the antenna, change voltage values. Once there is a positive voltage on "Data In" node (node 2) and negative on node 3 and after that node 2 is negative and node 3 positive. If the transistor source was connected to the body, for the situation where node 3 is positive and node 2 negative, the body-drain diode would turn on. Is that the behavior we would like to observe?
I would like to understand the following thing: in RFID passive circuits there are MOS transistors, which work as a clamp or a modulator. These transistors are in parallel to antenna. Drain is connected to one end of the antenna and source is connected to the other end. The example can be found here:
../imgqa/eboard/Antenna/rf-4v1g3ohmxng.jpg
The question is: where is the body of the MOS transistor connected?
Nodes on the antenna, change voltage values. Once there is a positive voltage on "Data In" node (node 2) and negative on node 3 and after that node 2 is negative and node 3 positive. If the transistor source was connected to the body, for the situation where node 3 is positive and node 2 negative, the body-drain diode would turn on. Is that the behavior we would like to observe?