How to Tell If a Wireless Is Vertical or Horizontal

The orientation of an antenna affects bot the transmission and the reception.

Wireless transmissions are polarized either linearly or circularly. Within the linear polarization, transmissions can be either vertical or horizontal. Typically, in applications where both transmission and reception are required the antennas will be polarized vertically; when the wireless signal is only broadcast, it's often polarized horizontally. Testing the polarization of a transmitting antenna requires adjusting the linear orientation of a receiving antenna and recording the signal strength. If cross-polarized antennas are used, the signal degradation can be up to 20 decibels. This is most important in long-distance wireless transmission such as that of a line-of-site Wi-Fi link.

Things You'll Need

• External linear antenna

Instructions

1. Connect the linear antenna to your computer and set it to be vertical, pointing straight up and down.

2. Press "Windows Key" and "R" on your keyboard. Type "Cmd" and press "Enter." Type "netsh wlan show networks mode=bssid" without quotation marks and press "Enter."

3. Locate the Wi-Fi network for which you are trying to determine if the antenna is vertical or horizontal. Record the signal strength, which will be expressed in a percentage.

4. Rotate the antenna 90 degrees. Press the Up Arrow on the keyboard so that the previous command shows again and then press "Enter." Record the new signal strength.

5. Rotate the antenna again and run the command. Repeat until you have four sets of signal strength numbers. Record whether the signal is stronger with the horizontal or vertical position of your receiving antenna. The strongest signal indicates the polarity of the transmitting antenna.

Tips & Warnings

• Internal and short-range Wi-Fi networks use multiple polarizations due to a multiple-in, multiple-out configuration. This MIMO setup increases performance over a short range, but is not ideal for a long-range wireless connection.

• Only connect to networks with permission. Connecting to a network without its owners' permission may be illegal in your area.

References

• Odessa Office: How to Pick the Right Antenna
• WLAN Antennas: Wireless Antenna Properties
• Astron Wireless: Antenna Polarization
• Antenna Theory: Polarization Measurements
• Intel: How Does MIMO use Multiple Antennas to Improve Performance?

Resources

• WLAN Book: 8 Free Alternatives to NetStumbler