I checked out the referenced web site. Not a whole lot of information, but I gleaned the following. Since the application is WAN/LAN, the antenna must be a low directivity broadcast type, probably a quarter wave stub or similar device. At 2.4 GHz, this amounts to 31 mm, or 1 1/4 ". A quarter wave stub looks approximately like a 35 Ohm load. Not too bad a match to 50 Ohms. I suppose you could shorten it up a bit to increase the load, but it becomes capacitive when you do that. Still not sure about the 30 dB pad. Is this when you are connecting together two PCMCIA cards without the intervening loss associated with the rf link? In any case, I don't know of any kind of coax that would provide 30 dB of attenuation with a reasonable length. For example, you would need almost 100' (30 m) of RG-58 to get 30 dB attenuation. Better off to use a 30 dB pad. As long as transmit power is low, this is a minor addition.
---------- >From: Muriel Bittencourt de Liz <[email protected]> >To: Ken Javor <[email protected]> >Cc: Lista de EMC da IEEE <[email protected]> >Subject: Re: antenna and cable for 2.4GHz >Date: Mon, Dec 6, 1999, 4:59 AM > > in detail the board details: > > http://www.mcc.com/projects --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
