| 摘要 |
A wireless keyboard and reader combination comprises a keyboard having a plurality of keys, an antenna, and a plurality of passive transponder circuits, employing backscatter transmission coded in the time domain using a reflected series of pulses, coupled to the antenna and associated with the keys. For example, SAW transponders may be employed. The passive transponder circuits are selectively coupled to the antenna and provide a coded response identifying a key in response to key activation. An associated reader includes a source of an interrogating field applied to the antenna of the keyboard and a decoder for determining the coded response from the passive transponder circuits. |
