Hao, just to add a suggestion to what Renaud has mentioned previously, I believe an Analog Devices ADG918 RF Switch (SPDT) may work for you. Its similar to the Peregrine switches he mentioned and is a much cheaper alternative to RF relays. http://www.analog.com/en/prod/0%2C2877%2CADG918%2C00.html And yes, I do work for ADI - but the reason I'm pushing them is because I've used them on boards in a similar application configuration to the one Hao described - and I believe they would work! Good luck with the project, Regards, Mike Hi there, I'm new on your list ! I hope my email will reach Hao ! If you look for = a switch, you can look at Peregrine semiconductor: = www.peregrine-semi.com. They build some RF switch like SPDT. The spec. = frequency is up to 3 Ghz. Ps. Sorry for my english ! Regards, Renaud ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu