Using BB60C at higher frequencies

Hello all 😀

I’m trying to make a decision on which SA to purchase. After going around and around on this it really comes down to the frequency range. The SA124B is able to capture up to 12 GHz whereas the BB60C is relegated to frequencies below 6 GHz.

I do understand there are a LOT of advantages (too numerous to mention) to the more expensive BB60C and it is the one I prefer but the frequency range is a bit of a limitation for us.

So I was wondering if any of the experts here had used some clever methods to using the BB60C at higher frequency inputs…such as X-Band (to 12 GHz) would be ideal for us.

Any thoughts/ideas would be appreciated. Have a great weeked!

jom

You can use a signal generator and mixer to downconvert to 1-2 GHz and feed into the BB60C. The mixer will drop amplitude 6-8 dB typically

Thanks Justin

OK, admittedly I kind of knew that already. I was hoping that there might be a setting in the SA that might get it above 6 GHz such as running at slower sweep speeds or some such.

Also, I was curious about the idea of moving down to 1-2 GHz in your suggestion. Is there a particular reason for that? Is converting down to, say, 5 GHz still OK? Just curious…

Frankly, I’m trying to talk myself into the BB60C but the SA124B might be a better deal. Is there something I might be overlooking here if I go with the lower cost model?

Thanks again!

jom

The BB60C has a lot of advantages: sweep speed, signal purity, instantaneous bandwidth, etc. But the SA124B is perfectly capable of making good measurements on many types of signals above 6 GHz. Crowded spectrum, signals wider than 40 MHz, or intermittent signals are difficult or impossible to measure with the SA124B.

You could downconvert to any convenient frequency, but there are a lot of off-the-shelf converters for satellite systems that target 1-2 GHz IF, and a lot of mixers that don’t allow an IF much higher than this.

If you are needing EMC pre-compliance then the BB60C is the better choice.

[joeqsmith]

Hello,

I had asked about providing support to Spike for external down conversion several years ago. Looking at the latest version of Spike, it still doesn’t provide support. It would seem like an easy feature to add and would save me a lot of time.

I would expect to provide the LO, the sideband, mixer loss (or maybe a way to calibrate it).

Shown is a down-convertor for the X-band, using a 12GHz LO. For a quick demo, a LiteVNA64 was set to 5.9GHz and measure directly with the BB60C. Next the LiteVNA64 was attached to the down convertor and set to 6.1GHz. 12 – 6.1 = 5.9. Also shown are the two overlaid.

Maybe the person uses a 6GHz LO with the upper sideband, or 6.1 – 6 = 0.1G for the previous example.

Both the down converter and BB60C are referenced to my GPS. That bit of drift is the from the LiteVNA64.

• This reply was modified 3 weeks, 4 days ago by joeqsmith. Reason: add photo

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