requirement to establish wlan

Hi

Patch antenna are usually not omnidirectional. I want to ask what are the specific requirement for the pattern of WLAN antenna and Patch antenna are suitable for this kind of applications

Sometimes a properly designed patch antenna can also provide a wide horizontal radiation pattern that is well suited for WLAN access points.
One idea is a family of dual-patch antennas:
About patch antennas:
http://www.emtalk.com/mwt_mpa.htm
http://www.emtalk.com/tut_1.htm
http://www.skycross.com/Technology/W...AN_Devices.pdf
http://www.skycross.com/Technology/W..._Notebooks.pdf
http://www.ansoft.com/news/articles/wlan.pdf
http://hcac.hawaii.edu/tcwct03/papers/s22p03.pdf

Let me be more specific and i am talking about single patch with probe fed.
The last example given by u the pattern is not omnidirectional
http://hcac.hawaii.edu/tcwct03/papers/s22p03.pdf

For WLAN Antenna requirement u can refer chapter 4 of the book Antenna for Portable Devices
https://www.edaboard.com/viewtopic.php?t=261152

Thanks its really a very nice source of help

There is no need for a WLAN access point antenna o be omni directional. Actually a reflector antennas are ideal when there is a need for beam control. I'm not sure why manufacturers use omni directional rubber duckies in access points. Probably to suite everyone's needs. Yet I have seen many people use home made reflectors to improve the patterns and signal strengths. Afterall you don't want your network covering the neighbours property, do you?

A have designed a couple of WLAN patch antennas, so I can say, that they are suitable for this purpose. The critical parameters include gain and return loss of the antenna. Tha gain depends on losses in the feeder and substrate and also on the radiating pattern. The narrower the beam, the higher the gain. For higher gain, you need higher number of patches, but losses also increases. The return loss is also important parameter, according to my experiences, there can be designed patch antennas with RL<-15 dB even RL<-20 in whole frequency band. And it is also possible to design an omnidirectional patch antenna.

I have went to a market and look many WLAN transceivers both for commerical and home applications. Interestingly all of them use simple wire monopole antenna (That surely do not have omni-directional pattern).
I have seem different kind of design for WLAN and pattern varies with reference to the antenna type. I wonder since WLAN is employed technology might have some standard pattern.