near field in mimo antennas
时间：03-31
整理：3721RD
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Lets say I have two monopole antennas in a WLAN receiver at 2.4 GHz, and they are spaced 10" apart. How far away would I have to put a test antenna to be out of the near field so that I can effectively test the mimo algorithms beamforming capability?
Added after 1 hours 43 minutes:
Let me re-phrase that question. To do 2 X 2 mimo beamforming at 2.45 GHz, I have two short monopole antennas connected to a wlan card. Each monopole is about 1" long. They are spaced 10" apart. Apparently I need to at least be far enough away with a test antenna to be in the Fraunhoffer reqion in order to focus the beamforming. To calculate the closest I can be to the unit with a test antenna, but still be in the fraunhoffer region, do I use the 10" spacing between the two antennas (as an "aperture width"), or the 1" length of the individual monopoles?
I want to put a test antenna a close distance away L, and have L be far enough away that the WLAN chipset can do beamforming "as if" the test antenna was "far" away.
Added after 1 hours 43 minutes:
Let me re-phrase that question. To do 2 X 2 mimo beamforming at 2.45 GHz, I have two short monopole antennas connected to a wlan card. Each monopole is about 1" long. They are spaced 10" apart. Apparently I need to at least be far enough away with a test antenna to be in the Fraunhoffer reqion in order to focus the beamforming. To calculate the closest I can be to the unit with a test antenna, but still be in the fraunhoffer region, do I use the 10" spacing between the two antennas (as an "aperture width"), or the 1" length of the individual monopoles?
I want to put a test antenna a close distance away L, and have L be far enough away that the WLAN chipset can do beamforming "as if" the test antenna was "far" away.