Spectral Mask

Last Updated: June 19, 2009

The Transmitter Spectral Mask measurement includes the in-band and out-of-band spurious emissions. This test specifies that the transmitted signal does not exceed the IEEE 802.11 a, b, g specified spectral mask. The reference level power is taken as the Power Spectral Density (PSD) in the signal.

Spectral mask margin is the worst difference between the spectral mask and the measured PSD. A positive value indicates the minimum margin by which the PSD passed this test. A negative value indicates the worst-case amount by which the PSD failed this test. This test ensures that multiple WLAN devices do not unduly interfere with each other. The spectrum test can be a good indicator of deteriorating performance.

IEEE Std 802.11b-1999 Paragraph Transmit spectrum mask
IEEE Std 802.11a-1999 Paragraph Transmit spectrum mask

The Inc Dynamic Range function is disabled.

Test Set Requirements: N8300A Wireless Networking Test Set Version A.02 and above.



Test Procedure Summary

The following steps summarize the procedure required to configure the WLAN DUT and the N8300, make the Measurement, and recover the results:

    1. N8300: Setup Frequency, for example Channel 1 at 2.412GHz.

    2. N8300: Setup Power Range, for example  5dBm.

    3. N8300: Setup Max Packet Length, for example 970e-6.

    4. N8300: Setup Frames Used, for example 10.

    5. N8300: Setup Trigger Style, for example  MagLevel.

    6. N8300: Setup Trigger Level, for example  0.3V.

    7. N8300: Setup Trigger Delay, for example -2e-6.

    8. N8300: Setup Trigger Holdoff, for example  60e-6.

    9. N8300: Select the standard of the DUT, for example 11a.

    10. N8300: Set the Reference level, for example 10 dBm, or select Auto.

    11. WLAN DUT: Setup frequency band, for example  802.11b

    12. WLAN DUT: Setup channel, for example  channel 1 at 2.412GHz (that is, N8300: = WLAN DUT Frequency)

    13. WLAN DUT: Setup transmit power

    14. WLAN DUT: Setup modulation type for example 11Mbps, CCK

    15. WLAN DUT: Start transmitting packets

    16. N8300: Press Init to make the measurement.