Discussion: Antenna Diversity

[Rayengine]

Re: re

see the book of handbook of propagation effects for vehicular and personal mobile satellite system in ebook upload forrum

Thanks for your information. The book is talking about the vehicular system, she took that the antenna is placed as wide as 1 meter. But I want to know that in consumer product level which is limited by size.

Is there any formula to clear related to Fading related to Antenna separation ?

Is there any simulation method (e.g Systeeemview - sytem design tool) to verify the system ?

Any good idea!

 

[johnseven]

There's no "closed form" formula to quantize the improvement over antenna separation.
From the ITT Radio Designer's Handbook real world tests have shown that the peak of improvement is about 10 wavelengths. The point of diminushing returns.

J7

 

[mbq]

I would like to share with you some informations here:

- Diversity is technology to get better received signal and it is most used in wireless telecommunication system. It is used when the signal comes to receiver is weak. In mobile telephony, we use it in BTS.

- The best use of diversity is using Polarised antenna. In case you want to use seperate antenna (means use to difference antennas), you have to put two antenna at the same direction and downtilt. The distance between antenna is depend on the way you want to get diversity: horizontal or vertical. For horizontal, the distance ~ 10 times of wavelength. For Horizontal, the distance ~ 6 times of wavelength.

- You need to take care that the distance here is between two main beamwidth. It means when you make the lines of two main beamwidth of two antenna, the distance between that two lines.

- In telecom, you know that the BTS is transmit at much higher power than the MS, so they only take care diversity at BTS, but not at MS.