3rd Wifi Antenna for T60

[artlogic]

I'm looking for source for the 3rd Wifi Antenna for the T60. I currently have a T60 with WWAN, and I'm looking to replace the WWAN antenna with the white Wifi antenna, but haven't been able to find the part. Does anyone know if these are available for purchase or trade anywhere reputable? Thanks!

[Johan]

Welcome to the forum!

... and I'm looking to replace the WWAN antenna with the white Wifi antenna...

I must admit that I am not quite certain what "the white WiFi" antenna is? Anyway, I guess the part you are looking for is defined on System service parts - ThinkPad T60, T60p standard screen (format 4:3 LCD) or System service parts - ThinkPad T60, T60p Wide screen. In either case you should be able to find the parts through IBM Maintenance parts (or, perhaps, eBay or Taobao).

Alternatively, try post a "WTB" (Want To Buy) of "LF" (Looking For) in the Marketplace of this forum.

Johan

[RealBlackStuff]

The 3rd antenna is meant for MIMO, but IMHO effectively does little to improve reception...
Basically ANY antenna you can find from ANY brand laptop will work.
The only thing you need to check is enough length of that cable.
Remove the LCD from the lid, then put the metal antenna-part to the right of the Thinklight.
Mount it similar to the left antenna that is in there already.
If necessary, bend the new antenna so it fits tightly in that slot, cut off whatever you feel is too much.
Put Kapton tape or similar over the metal bits of the antenna.
Make sure it does not sit any higher than the Thinklight.
Make sure the wire from the lid-sliders can still move freely and does NOT make contact with the antenna.
Feed the new antenna through the left hinge (so it comes out above the fan).

[dr_st]

Can't you just route the WWAN antenna to the Wifi card? Is it not long enough?

[Saucey]

Can't you just route the WWAN antenna to the Wifi card? Is it not long enough?

I believe it should be... They seem equal lengths apart.

I thought they supported different wavelengths Gonna try this on my unit today! Thanks RBS!

[Johan]

I thought they supported different wavelengths. Gonna try this on my unit today! Thanks RBS!

You are correct in that WLAN (= "WiFi") and WWAN are using different frequency ranges, and that the antennas for WLAN and WWAN are therefore designed and optimized for the respective, different bands. Nevertheless, various ThinkPad users have used the original WWAN antenna for WLAN; see e.g. WWAN antenna useable for WLAN? and T60 1953-DAU & WWAN.

You will get an idea of the different frequency ranges in e.g. Sierra MC8775 HSDPA 3G Wireless WWAN Card for Thinkpad T6x/p, X6x/S/T, R6x, and Z6x Series or ThinkPad Mobile Broadband Global Half Wireless WAN Module - Overview or MC8755 PCI Express Mini Card module selected by Lenovo for integration into ThinkPad T60 and X60 business notebooks (the latter is the European frequencies).

What happens if you use e.g. a WLAN antenna for WWAN (or the opposite) is that you will experience some amount of impedance mismatch, which in turn will give rise to a certain reflection-loss, which will reduce the usable range of the particular antenna/link. Why does the impedance matching matter in antennas? Because we seek to obtain complex conjugate matching between the WWAN or WLAN transmitter, respectively the receiver, and its load, respectively its generator or source impedance (= in both cases the antenna). If you e.g. see the paper Internal Laptop Combo Antenna for Celluar/WLAN Dual-Network Operations (just have a look at Figure 3), you will see the different bands that the WLAN and the WWAN antennas are optimized for; the higher the negative number on the left-side scale is, "S11" and S22" (the so-called return-loss), the better the impedance-match. In the real world, an antenna having return-loss of -10 dB (or perhaps even -8 dB or -6 dB!) is OK for a low-performance application, such as WLAN and WWAN, but as the return-loss decrease below -6 dB, the reflection-loss will increase dramatically (see the table e.g. here), which will reduce the usable range (try Google for e.g. "WLAN link planner" and play with the numbers to get an impression).

So, bottom line, a WWAN antenna can be used as a WLAN antenna (and vice versa), but with reduced performance.

Johan

[artlogic]

Wow! Thanks for all the information. It turns out I'm looking for 42R9909, and I'll be sure to check in the marketplace, as the sources I've found online seem a bit pricey.

I especially appreciate the installation instructions and the tutorial on antennas (a subject I know very little about). For the moment I believe I'll use the WWAN antenna, but eventually I'd like to replace it, if only to get rid of the protrusion it causes.

Thanks again for all the help!

- James

[Saucey]

Hmmmm... well I currently have only two cables connected to the wifi on my T60p, my guess is that upgrading the wifi and slapping that third WWAN cable to it would be like snake oil then. I'll try it out to see if it makes a difference. Probably negligible, but then it'll make use of it.

I kinda like how the WWAN sticks out to the right of the lid of the laptop.