【SA Q&A】will provide you answers to the problems you may meet when using a spectrum analyzer. If you have any questions about spectrum analyzers, please drop an email to us sales@salukitec.com. We are more than glad to provide you the answer and publish in our articles.

Figure 1  S3331A handheld spectrum analyzer

Q1: Resolution BandWidth (RBW) the smaller the better?

Answer: The smaller the RBW, the better the sensitivity of the spectrum analyzer, however, the slower the scanning speed. It is best to set the RBW according to the actual test needs, to find a balance between sensitivity and speed – both to ensure accurate measurement of the signal can get fast measurement speed.

The DANL is linked to RBW.  1/10 RBW setting will enjoy a 10Db lower DANL. For example, DANL is -110dBm @ 10Hz RBW. Then DANL will be -120dBm @ 1Hz RBW. Most of the spectrum analyzers in market show their DANL specification @1Hz RBW. However, Some of these spectrum analzyers’min. RBW can only achieve 10Hz, means the real min DANL is 10Db higher than the specification shows. All Saluki’s Spectrum analyzer can reach 1Hz RBW

Q2: How to select the right Average Type? power? logpower? voltage?

Answer: logpower Logarithmic power average: also known as video averaging, this average method has the lowest noise floor, suitable for low level continuous wave signal test. However, “noise-like” signal will have some error, such as wideband modulated signal w-cdma and so on.

Average power: also known as rms average, this average method is suitable for “noise-like” signal (such as: cdma) total power measurement.

Voltage averaging: This averaging method is suitable for observing the rise and fall time measurements of an AM signal or a pulse modulated signal.