SATSAGEN for ADALM-PLUTO


  • Dear all,

    I have just found the program SATSAGEN by Alberto IU1KVL on the web.

    It turns a Pluto into a very useful measuring device. A generator and a spectrum analyzer were realized, whereby the entire frequency range of the Pluto is supported.

    In the "Spectrum Analyzer w/Tracking" mode, for example, filter passband curves can be determined very easily. As a very first test I measured a 2.4GHz filter, see screenshot. For tuning and matching of antennas, only a suitable directional coupler would be required in addition.

    At Albertos blog you find the download page and also a video with helpful explanations:


    http://www.albfer.com/en/2020/02/21/satsagen-2/


    Thanks to Alberto, who provides SATSAGEN to the HAM Radio community free of charge.

    73 de Roland

  • I bought a bridge about two years ago, and now he should be somewhere in the workshop, using him with PLUTO and theoretically measuring antenna return loss... Well, there seems to be a need for user calibration procedures

  • Hello friends!

    The other day I tried the program. Well done! I shake a hand to the author. The author is well done!

    I already have thoughts on how to make a good addition. The main minus of what is now is a very uneven input and output impedance. The authors solves this problem by applying ATT at the input / output, but this is "сrutches". There are special MMICs with regulated entry and exit with a good S11 and S22 - this is MGA30889. The only thing that upsets is that it is available - it only works up to 3GHz. But, in principle, what is available for immediate tasks is suitable. With additional ATT at the input / output of these MMIS - we get an almost perfect 50-ohm path! Also, I found a wider chip with good S11 and S22 - HMC482

  • Could you give more information on the bridge that you are using please?


    I want to make RL measurements on my POTY and that looks like a very nice way to do it.


    Jonathan

    Jonathan Naylor

    Callsign: G4KLX

    Locator: IO90TT

    QTH: Worthing, UK

  • You don't really need a full bridge for this and could use practically any directional coupler that works at 2.4 GHz. In this case all we really need to know is the coupling factor which you can find quite easily in forward mode, putting a load on the through port and measuring what you get on the coupled port. Then just turn it round to sweep measure the reflected power and take into account said coupling factor.


    Mike

  • This evening I did also some reflection measurements, but using a -30dB directional coupler.

    Low cost (but good) directional coupler


    The setup was simple: The Pluto-Tx was connected to the (reversed) dico input via an attenuator (-10dB) and the Pluto-Rx was connected directly to the -30dB output to measure the reflected power. So the corresponding SATSAGEN settings for "level correction" were -10dB for Tx and -30dB for Rx. A calibration was then performed, with the dico main output being short-circuited. The first screenshot shows the behaviour of a quite good 50 Ohm termination resistor at the dico output.



    After that this procedure was repeated, but for calibration the output was simply left unconnected (open).



    Finally I connected a 14 dBi wifi flat panel antenna.


  • If I don't get it wrong then yes;After connecting the bridge, perform 1: short circuit 2: open circuit calibration at the reflection port.Then I was asked to measure the same 915MHz antenna for comparison.The results are as follows:

  • Hi all!


    the new version 0.2.2 of SATSAGEN is available at the link below:


    http://www.albfer.com/satsagen-download-page/



    Highlights of v. 0.2.2:


    - Extension of analyzed band from 6 GHz to 12 GHz and beyond! (harmonic third mode)

    - Multiplier offset RX/TX TSA in order to test amplifiers or multipliers

    - Offset between transmitter and receiver in order to test conversion systems, like transverters

    - Display and modify SA resolution bandwidth

    - Save/Load TSA scans (by memory or files)

    - VSWR unit

    - Multiple TSA markers

    - Multiple SA markers

    - Calibration using a directional coupler or bridge, averaging open and short

    - Generator/Sweeper Mode

    - SA Span value - scale coherency

    - Lock Zoom autoscale when TSA or SA restarts

    - All knobs can drived by the mouse wheel

    - Pause and step functionality

    - Output sweep ramp with external USB D/A

    - Backup and restore configuration to and from a file.

    - Connection string Override

    - Frequency reference setting


    Video:



    See you soon!


    Cheers


    Alberto