| 摘要 |
When multiple readers (300) for RF transponders (104) have to be placed in close proximity, such as in adjacent landes of a highway toll barrier, they can be set to operate at different frequencies. When signals from two adjacent ones of the readers interfere, the resulting signal includes interferecne terms whose frequencies equal the sum of the reader frequencies and the difference between the reader frequencies. To remove such interference terms while passing the desired terms, a reader (300) includes a low-pass (306) or other frequency-selective filter. |
