An RF signal generator is an important part of my wireless workbench. In the lab, I use high end gear made by HP, Marconi, or Anritsu, but these are big expensive pieces of equipment with loud fans so I don’t want them at my desk. Enter the TPI-1001B RF signal generator/analyzer from RF-Consultant. This is a USB-powered signal generator that generates clean RF CW signals from 35MHz to 4.4GHz at up to +10dBm…and does it accurately! It even has an accurate power detector that can be used in conjunction with the generator to sweep filters and such (more below).

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The TPI-1001-B generator/analyzer costs a good deal more (~$350) than the cheap RF signal generators on eBay. I assume it is based on the same Analog Devices ADF4351 synthesizer, but the price difference is fully justified. The cheap synthesizers are not calibrated for amplitude and many don’t use a good enough time-base to be accurate for frequency either. A signal generator without accurate frequency and amplitude is a toy, this is a tool.

Note: they offer a less expensive (~$275) version (TPI-1002-A) that has the same signal generator but does not include the analyzer (which I thought it was worth the extra $75). I might buy one of these later for another workstation.

The good news is that both the generator and the analyzer work extremely well. The software is straight-forward and easy to use; I love the frequency presets. The device is compact, silent, and performs admirably. I’ll share some pics below of the CW output including sweeps of a few filters. As promised, it stayed well within 1dB of the configured output setting across a wide range of frequencies and the frequency accuracy was impressive as well (the measurements below are from a spectrum analyzer with a rubidium standard).

The main difference between the TPI and a lab-grade generator is that it lacks output filtering to suppress harmonics (you’ll see that in the pics too), but that’s expected.

As it is, it replaces the lab gear for most of my needs, but here’s my wish list for future versions:

• A set of switchable ceramic or SAW filters would add little cost and make their calibration process more complex, but it would make the generator able to fully replace lab-grade gear in many applications. Johanson makes great low cost SMT ceramic filters.
• An internal FM modulation generator.

Below are some tests I ran with the generator into an Anritsu MS8609A transmitter analyzer. I did not compensate for cable loss, but it was a short, high-quality (low loss) cable and the results speak for themselves.