reducing the signal strength of an RF module

[natasie]

hey everybody,

do you have any idea how to reduce the signal strength of an RF module. for project demonstration, a vehicle moves into an RF zone and immediately, his car slows down. i have been asked to do this for my small demonstration which should be about 30cm maximum. i am supposed to show the vehicle drive freely on a free zone and am supposed to show it slow down in a rf zone and continue to drive freely when it gets out of the rf zone and this has to be done on a small board.

can anyone help me with a suggestion? can i connect anything to the TXD and RXD pin of the transmitter and receiver module? like a capacitor or a resistor? the frequency is 433MHz thanks.

 

[jiripolivka]

As you give no details on your "RF modules", it is not easy to advise. At 432 MHz, try to find where the antenna is, and turn it away from a target. You can also cover the module in aluminum foil to prevent it from radiating too much. Leave only a narrow slit in the wrap, and see what happens.
If aluminum attenuates too much, try to enclose the module in a lossy enclosure, like a metal box with a hinged lid; then by opening or closing, the lid, you can adjust the range.
The best way, if your RF module is a transceiver with a common antenna, I would disconnect the antenna and connect another one through an adjustable attenuator.

 

[natasie]

ohh thanks

i really like the aluminium foil idea because its d most feasible for me right now because am not planning to connect an antenna to the rxd to reduce signal strength. i will try the aluminium foil. i do not mind wrapping the transmitter about 2 or 3 times to get a desired range of transmission.
thankyou

oh but secondly, what is an adjustable attenuator?