I would think attenuators and booster amps may as well be in the external cables.
Not terribly familiar with all this, perhaps there are special tricks involved to measure
something like s12 on an amp?
Adding them to a $300 VNA board adds complication and sources of trouble.
Modular is good when it comes to seldom needed features.
The ability to use a different bridge would be interesting.
Perhaps lay out the board such that one could insert vertical SMA's
and stir some surface mount parts to accommodate this?
Yet another product variant for Hugen to sell at some time in the future.
But I suspect most nanovna users have never felt the need for an external bridge.
Requiring an external bridge for all work with the VNA is perhaps a bridge too far
towards modularity.
Jerry, KE7ER
toggle quoted message
Show quoted text
On Tue, Sep 29, 2020 at 08:47 AM, Jim Lux wrote:
yes, it's going towards the fieldfox type of capability, not the "bench VNA" -
The latter would typically bring out the source and receiver inputs with a
loop, so you could use different bridge or insert attenuation to make it
easier to test amplifiers.
This design has a 30dB sep attenuator, but still, if you're testing a LNA with
a maximum input of -70 dBm (because it's designed to receive signals at -150
dBm) this probably isn't your box of choice. Assuming he's putting +10 into
the attenuator, the output power will be -20 dBm or around there. That's
enough to saturate a lot of LNAs.
Likewise, if you were testing a 10W PA, you might want a booster amplifier in
the drive on port 1, and an attenuator in port 2.
