One antenna for WLAN and Bluetooth

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hqqh

Joined: 07 Feb 2002
Posts: 255
Helped: 8
Location: www

11 Oct 2008 16:51 bluetooth antenna in wikipedia

Hi,

is it possible to use only one antenna for a WLAN / Bluetooth application if the antenna is multiplexed? Does someone know such a device? I thougth it can be implemented like this:
PCB antenna (2.4ghz) --> Multiplexer |--> Balloon 1 --> RF IC1
................................................. ...|--> Balloon 2 --> RF IC2

regards
hqqh

vfone

Joined: 10 Oct 2001
Posts: 2328
Helped: 327

11 Oct 2008 19:16 Re: One antenna for WLAN and Bluetooth

“A balloon is a flexible bag filled with a type of gas, such as helium, hydrogen, nitrous oxide or air”
http://en.wikipedia.org/wiki/Balloon

Probably you want to say balun (BALanced to UNbalanced)
http://en.wikipedia.org/wiki/Balun

I don’t think that a balun can help to switch one antenna to 2 transceivers, that works simultaneous on the same frequency.

hqqh

Joined: 07 Feb 2002
Posts: 255
Helped: 8
Location: www

11 Oct 2008 21:25 Re: One antenna for WLAN and Bluetooth

hi vfone,

thank you for the spelling check Smile

.
I thought two baluns are needed in the case that RF IC 1 and RF IC 2 have different input/output impedances. I don't want the balun to do this switching thing. for this task the multiplexer should be there.
For the application i have in mind, i just need to receive data in a short time frame using RF IC 1 and after this, i want to send data for a short time frame using RF IC 2. So the reason, why i want just one antenna is to save pcb area.
And i thought in mobile phones the antenna is used for gsm and gps together. So it seams to be a solution for this problem, isn't it?

Any ideas?

regards
hqqh

Kohi_boy

Joined: 20 Apr 2008
Posts: 133
Helped: 15

12 Oct 2008 2:00 One antenna for WLAN and Bluetooth

How about a circulator since you dont need to transmit and receive at the same time ?

vfone

Joined: 10 Oct 2001
Posts: 2328
Helped: 327

12 Oct 2008 11:11 Re: One antenna for WLAN and Bluetooth

GSM and GPS use different frequencies.
I don’t think you can use the antenna just for receiving WLAN and Bluetooth protocols. You have to transmit also, to maintain the link connection. And when you transmit you need an isolation between transceivers.

hqqh

Joined: 07 Feb 2002
Posts: 255
Helped: 8
Location: www

21 Oct 2008 20:51 Re: One antenna for WLAN and Bluetooth

Hi all,

ok, I found a device which seems to be suitable: Analog Devices - ADG936 RF switch. wideband 4GHz, high isolation between these two channels.
@vfone: as I said, only one rf transceiver is active at the same time. during this time the active transceiver can receive and transmit data. So I think it should work.

Regards
hqqh

kyg

Joined: 06 Dec 2007
Posts: 90

14 Nov 2008 10:27 One antenna for WLAN and Bluetooth

do you know any type of the antenna that suitable to design for bluetooth and wifi band frequency?
i want to design the antenna for bluetooth and wifi application. i need to find which type suitable. i already try to tuning monopole antenna but it is hard to get dual band(bluetooth and wifi)

regards,
kyg