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IQ Signal Generator

The IQ Signal Generator block generates an I/Q stream based on the selected generator type(s):

IQ Signal Generator Block

Left hand side Input:

  • IQ

Right hand side Output:

  • IQ


You can adjust the Sample Rate (up to 20GHz) and Center Frequency. If you select a Frequency Profile the Sample Rate & Center Frequency settings can be adjusted fully automatic by setting the corresponding checkboxes. In addition you can also add a Time Offset (within +/-200ms) which might be of great help if you want to combine multiple I/Q streams.

Varios Generator/Modulation types are available:

  • Sweep (Incl. Single Carrier, Multi Carrier & Power Ramp function)
  • Noise (Within -200dBm to 0dBm)
  • Pulse (down to 10nS Pulse and Pause rate)
  • FSK (With up to 20MHz Symbol Rate)
  • GFSK (With up to 20MHz Symbol Rate)
  • QAM (Modulation types supported: BPSK, ASK, QPSK, QPSK-C, 16-QAM, 64-QAM, 256-QAM, 1024-QAM, 4096-QAM with up to 20MHz Symbol Rate)
  • OFDM (Modulation types supported: BPSK, QPSK, QAM16, QAM64, QAM256, QAM1024, QAM4096)
  • Raster Image (Load a JPG, PNG, BMP or TIFF and convert it to I/Q)
  • Echo/Reflection

All Generators can be combined or even added multiple times even with different settings: 

IQ Signal Generator Settings


A 4096-QAM Constellation Diagram with 20MHz Symbol rate:

A QAM 4096 Constellation Diagram with 20MHz Symbol Rate


Step Sweep Screenshot:

I/Q Signal Vector Generator Step Sweep Demo


You can use the IQ Signal generator to send an I/Q stream to the Tx of the SPECTRAN V6 to use it as a Vector Signal Generator (up to 120MHz Sample Rate/RTBW).

Another great feature is the I/Q stream mix: You can add an additional I/Q Signal Generator stream to the regular I/Q stream coming from the SPECTRAN V6 Receiver. Or why not stream the IQ Signal Generator as an I/Q file to disk and use it with an third party vector signal generator?

IQ Signal Generator Typical Missions



CorNicWest has reacted to this post.


We changed the frequency steps to 1Hz (was 1kHz) resolution.


We added a "Shift Filter" feature to the FSK Encoder. With its help you can smoothly change the encoder from FSK (0% Shift) to GFSK (100% Shift).

CorNic East has reacted to this post.
CorNic East


We added a "Power Ramp Duty Cycle" adjustment to remove "glitches", which might have occurred from time to time.

You should now get a glitch free signal no matter what:

Glitch Free Power Ramp RF Signal Generator

Check out our latest video showing the IQ Signal Genarator running complex QAM modulations up to QAM4096: IQ Signal Generator Demo

The IQ Signal Generator offers an optional Raster Image generator. The Raster Image generator can read an image from a file and converts each horizontal line interpreted as spectrum  into a continous IQ data stream. You are then able to see the loaded image in a spectrum waterfall. In attached mission you need to specify the path to the  image file.

Input image:

Output spectrum waterfall (note: waterfall time compression needs to be set very low for this to work properly, higher values will compress the generated image vertically):


An additional bitmap coverted to IQ, now as geyscale image for better contrast:

Bitmap to RF IQ data

You can order the Raster Image option on our online shop

We have raised the Symbol Frequency limit from 20MHz to a whopping 100MHz.

Make sure to use a high performance system when using high symbol rates otherwise your CPU Sat for sure will run into 100% which will result in to a useless signal output (see screenshot below).

100MHz IQ Symbol Frequency

We added basic waveforms as there are:

  • CW
  • PWM
  • Triangle
  • Sawtooth
  • Sine (sinwave)

You can select those from the Generator menu under "Add Basic Waveforms":

Select Basic Waveforms


Basic Waveforms


Josef, Sofon and 3 other users have reacted to this post.
JosefSofonpmarCorNic EastHB9DTZ

We added a Random Step mode:

Random Step Sweep