In this blog post we will look at Agilent's new family of waveform generators, the 33500B series. The new family is made up of 8 models that offer bandwidths from 20 to 30 MHz and offer one or two channels. The 33500B family features the exclusive Trueform waveform generation technology. Trueform technology plays every point in an waveform, unlike the incumbent direct digital synthesis (DDS) technology which only provides an approximation of a waveform (not every point is played). Also Trueform technology delivers waveforms with extremely low jitter typically around 4 ps of RMS jitter, which is more than 10x less jitter than a DDS generator. I will have more detailed info on Trueform in a future post. Here are some more 33500B series headlines:
- Full bandwidth pulse and square waves
- Sine waves with 5x lower harmonic distortion
- IQ signal player option
- Advanced modulation features such as sum modulation and channel to channel modulation
- 16 bits of resolution with 1 mVpp to 10 Vpp amplitude
- Noise function with variable bandwidth adjust and no repetition for over 50 years of continuous play
- The ability to upload arbitrary waveforms and sequences without a remote connection
For the two channel version there is an IQ signal player option available. IQ signal waveforms can be played from the 33500B without the option, but the option adds an easy to use single user interface for setting up and controlling both channels at once. Also the option offers features such as channel skew adjust and balance control for adding non-ideal conditions to the signal to test the limits of your design.
For an IQ example a 64 QAM baseband signal was created in software. It was then uploaded to and played by the 33522B waveform generator using the IQ signal player option. The resulting IQ baseband signal was captured by a high performance scope using vector signal analysis software, as shown in the below figure.
With Trueform technology the 33522B was able to deliver a 64 QAM baseband signal with only 0.3 % error vector magnitude! Notice too that the phase error is in milli-degrees and the magnitude error is in mV.
In my next post I will go into more detail on what Trueform technology is and do some comparison measurements with DDS. As always if you have any questions related to this post please feel free to email me and if you have something to add use the comments section below.