Here are tables that identify key features and options of SIGLENTs analyzer products to help you choose exactly what you need:

SIGLENT Analyzer Features:

SIGLENT Analyzer Options:

Tracking Generator included free with all SSA3000X, Plus, SVA, and X-R series analyzers

1- SSA3000X options
AMK – Advanced measurement kit
EMI – Electromagnetic Precompliance option
REFL- VSWR/Reflection coefficient measurement option requires an external return loss bridge or coupler like SIGLENT RB3X25

2- SSA3000X Plus options
AMK – Advanced measurement kit
EMI – Electromagnetic Precompliance option
REFL- VSWR/Reflection coefficient measurement option requires an external return loss bridge or coupler like SIGLENT RB3X25
AMA- Analog Modulation Analysis
DMA- Digital Modulation Analysis

3- SVA1000X Options
AMK – Advanced measurement kit
EMI – Electromagnetic Precompliance option
AMA- Analog Modulation Analysis
DMA- Digital Modulation Analysis

4- SSA3000X-R Options
AMK – Advanced measurement kit
EMI – Electromagnetic Precompliance option
AMA- Analog Modulation Analysis
DMA- Digital Modulation Analysis

Here are quick links to the product categories:

SSA5000A

SSA3000X-R

SSA3000X Plus

SSA3000X

SVA1000X

The post Analyzer Features and Options Table appeared first on Siglent.

IMD is an important test for verification of audio amplifiers and radio receivers as high IMD can cause audible distortion that can decrease the quality of the transmission.

In this experiment, AA7U and N4CY use a SIGLENT SDG2042X generator to deliver the IMD tones and a SIGLENT SSA3X spectrum analyzer to measure the result.

They also build some filtering to help decrease the harmonic content of the generator and build a coupler with better performance than commercially available products.

***

Siglent SDG2042X (AWG) Dual Channel Arbitrary Waveform Generator set up for use in IMD Test Set

1. Turn on the AWG (arbitrary waveform generator) — wait for it to initialize.
2. Frequency is highlighted, with 1 kHz the default. Enter “3”, then touch “MHz” at the bottom left. (By touching the screen where it says Frequency, you can enter the frequency on the keypad “3” then at the bottom of the screen touch “MHz” and that will set the frequency).
3. You will need to be set to 3 MHz (3.007 MHz) on Channel 1 and set 4 MHz (4.011 MHz) on channel 2 (Note: The reason for using the odd frequencies is the Siglent SSA3021X (SA.. or Spectrum Analyzer) has a sub-harmonic spur at 5 MHz)
4. Load–HI Z is the default. Select “50 Ω” at the bottom, by touching the screen.
5. Amplitude–2.00 Vpp is the default when in 50 ohms load. Enter “0”, then touch “dBm” on the bottom (fifth one over from the left–Vpp; mVpp; Vrms; mVrms; dBm). Make sure to set dBm.
6. Output–OFF is the default. Touch it and it turns ON and the Ch1 indicator turns on with the button also, by its BNC connector.
7. Repeat the above for Ch 2 as described above.
8. Adjust Amplitude settings for each channel, which are going through the Band Pass Filter (BPF), 3 dB attenuator, combiner and DUT under test for a 0 dBm on the SA, with the SA internal Attenuator set at -20 dB.

(Note: As an example, this will be around (~ -10dBm). Make sure that the 3 MHz BPF is connected to the 3.004 MHz Channel and the 4 MHz BPF is connected to the 4.011 MHz Channel.

IMD Test Setup–Spectrum Analyzer setup for Siglent SSA 3021X

There are two parts to the setup–the first part sets the levels at the DUT output to 0 dBm; the second part measures the IMD.

Part 1

(Calibration) Push “Preset”, Top Right, to set up for initial setup.

Set Center Freq 3.5 MHz, Span 6 MHz, Amplitude Ref Level +10 dBm

1. Connect the DUT (Power On) output to SA input. Tune to one, either the 3 MHz, or 4 MHz test tones on the AWG. Adjust the generator (AWG) for 0 dBm on the SA, within 0.1 dB. Tune to the other test tone, adjust the generator for 0 dBm.

SA: Recheck each tone again to make sure nothing has changed. This concludes the initial setup.

Part 2

1. Disconnect the DUT output from SA and connect it to the Reject Filter input (Which has the 20 dB built-in Attenuator). Connect the Reject Filter output to SA RF input.

2. Now look at the 4 IMD frequencies.

• • Span set to 1 kHz
  • Amplitude turn Preamp Off; set Ref Level to -60 dBm, Set Attenuation to Manual and set Attenuation to 0.00 dB.
  • Push the Trace button and look for and select “Avg Times 100”, which is located on the right bottom side of the screen.

The 4 frequencies you will be looking at are: Center Freq 1 MHz (1.004 MHz), 7 MHz  (7.018 MHz), 2 MHz (2.003 MHz) and 5 MHz (5.015 MHz),

3. You should now be seeing the 2IMD product in the center of the display 1 MHz (1.004 MHz). Push the Peak button or push Marker button and use the main tuning knob to tune to the peak of the signal. It will probably vary up and down, but wait for 100 averages and decide what the middle value is and write that down.

4. Tune to the 7 MHz (7.018 MHz) 2IMD product and note its level–write that down.

5. Tune to 2 MHz (2.003 MHz) 3IMD product, this will normally be much weaker, where the SA’s preamp may be needed to see it. Write down that level.
6. Tune to 5 MHz (5.015 MHz), write down that level. You now have measured the four IMD levels.

Use the formula for determining OIP2. (2IMD level – Reject Filter loss at that frequency 1 and 7 MHz) = OIP2.

Determine the OIP2 for both 2IMD frequencies. They are usually different–use the worst case, or specify both Output Intercepts.

Use the formula for OIP3. (3IMD level – Reject Filter loss at that frequency 2 MHz and 5 MHz) /2 = OIP3. Determine OIP3 for both 3IMD frequencies. Usually, they are about the same.

Examples

My reject filter has a -21.6 dB loss at 1 MHz; -20.39 dB loss at 7 MHz for the 2IMD frequencies. There is a -20.65 dB loss at 2 MHz and -22.62 dB loss at 5 MHz for the 3IMD frequencies.

The examples used in the below calculations were taken from the above IMD sweeps.

1 MHz (-109.65 dBm) – (-21.6 dB loss) = (109.65 – 21.6 = 88.5) = +88.05 dB OIP2.

7 MHz (-111.66 dBm) – (-20.39 dB loss) = (111.66 – 20.39 = 91.27) = +91.29 dB OIP2.

Normally you take the worst case and state that, which would be +88.05 dB

2 MHz (~-112.9 dBm) – (-20.65dB loss) = (112.9 – 20.65) = 92.25/2 = +46.13 dB OIP3.

5 MHz (~-111.66 dBm) – (-22.62 dB loss) = (111.66 – 22.62) = 89.04/2 = +44.52 dB OIP3.

Normally these should be very close, otherwise take the worst case, which would be +44.62 +dB
and state that.

System IMD Intercept Test with Band Pass Filters, Combiner and 3 MHz and 4 MHZ Band Rejection Filter connected to the SA

They are all at the noise floor, which is very good. It took adding Band Pass Filters in place of Low Pass Filters to achieve the results Below.

1 MHz (1.004 MHz)  -151.26 dBm

7 MHz (7.018 MHz   -152.45 dBm

2 MHz (2.003 MHz)  -153.51 dBm

5 MHz (5.015 MHz) -152.26 dBm

These are the simple formulas for second and third order IMD, you can take any two frequencies and work out the IMD products

Second order:     F1 + F2;    F2 – F1

Third Order:   2F1 + F2;   2F1 – F2;   2F2 + F1;   2F2 – F1

3 MHz and 4 MHz tones: 3 + 4 = 7 MHz ; 4 – 3 = 1 MHz; 6 + 4 = 10 MHz;  6 – 4 = 2 MHz;  8 + 3 = 11 MHz;  8 – 3 = 5 MHz

Building the Bandstop Rejection Filters

The easiest way to build and tune this filter is to test each Dipole (Tuned Circuit) by its self. It should be 3,250 kHz. Below is a sweep from my VNA, as this is what I used to check and tune each Dipole. I was able to tune the parallel circuits by having one side soldered to its pad and then connect the other end after tuning. You can also use the SIGLENT SSA3000X, SSA3000X Plus, or SVA to tune the filter.. as shown in this note on Filter Testing Using a SIGLENT Spectrum Analyzer

Below is a sweep of the final Band Rejection filter that is being used for IMD testing. There is around 58 dB rejection for 3 and 4 MHZ

Below is the finished 3/4 MHz  Bandstop Filter and Sweep

Below is a sweep of the final Band Rejection filter that is being used for IMD testing. There is around 58 dB rejection for 3 and 4 MHZ

A 20 dB pi pad can be done with 62 ohms shunts and a 270 ohm in parallel with 3300 ohms for the series resistor. (249.6 shown on the diagram. The theoretical value is 248 ohms.)

Both the 3 MHz and 4 MHz Bandpass filters are easy to build if you will tune each pole and install it as you go. I have marked the frequencies in Red for each pole. Also, I have indicated which Micrometal Toroids that were used with the turns required for each pole. You may have to make some adjustments to each of the poles, as there are variations from lot to lot with the toroid core. I also found it helpful to use an LCR meter to make adjustments in the turns count to get the desired inductance. I used an Array Solutions VNA2180 to tune each pole and evaluate the final filter. A SIGLENT SVA1000X VNA can also be used.

4 MHz BPF

3 MHz BPF

AA7U Hybrid Combiner

The loss through the filter is 6.13 dB/5.95 dB and the isolation between the two input ports is 74.58 dB at 3 MHz and 73.97 dB at 4 MHz (Measured with a 50Ω Termination at the output port.) After completing and testing the filter I filled it up with hot melt glue.

Below is a sweep of the Hybrid Combiner between the two input ports and it was terminated with 50Ω at the output port.

This is a sweep showing the two test tones 3 MHz and 4 MHz using the Hybrid Combiner. Notice how sharp they are.

How to take screenshots of the Siglent SA

Insert the thumb drive into the front USB port of Siglent.
You should see a blue USB icon in the upper right-hand corner of the screen.

Hit the File button
You should see a file directory similar to what you would see on a PC.

Under the Folder column, you should see two directories:

Local: free 80.74 MB (your size may be different)
+U-disk0: 748.00 KB/975.88 ME (your size may be different)

On the right-hand side soft keys, the “Save Type” should be PNG.
Hit the button and select JPG (or whatever file type you want – CSV, LIM, JPG, BMP, etc.)

Rotate your frequency tune knob and select your +U-disk0 directory
You should see the files currently on your thumb drive

Hit the Enter button
Hit the Operate button
Hit the Marker button
You should now be back at your main display screen

Setup a screen that you want to save
Hit the Save button
A pop-up window will show you a default file name of Name: JPG1 and an Input type: abc
I like to use a numeric file name, so I hit the +/- button
Now I backspace out the default “JPG1” file name
I enter the numeric name that I want to use. Example: 111
I find it quicker to use quick numeric file names and rename the file once the thumb drive is attached to my PC

Hit the Enter button
You may or may not see a brief text message on the screen about the screen being saved to your thumb drive.

To confirm that the file was saved to your thumb drive, Hit the File button
Use the Frequency control knob and select your thumb drive directory
In the directory listing for the thumb drive, you should see your recently saved screen snapshot

For some reason, the screen sometimes saves to the internal Siglent memory. When this happens, I go through the steps again about setting up a save to the thumb drive. I suspect that my steps are a little flakey in this area.

Once the Flash drive is set up you can save the screenshots by pressing the Save button, which will number the shot and then press the Enter button.

The post Inter Modulation Distortion (IMD) testing appeared first on Siglent.

A very helpful SIGLENT owner, Dan from Alabama Broadcast Services, LLC, built an FM NRSC Mask tool using our original AM NRSC mask python code

This program was built using Python 2.7 and helps create masks around user-defined center frequencies.

Here is a link to the zipped download of the finished Python code: SSA3XNRSC_FM_Limit.zip

NOTE: For NRSC transmitters > 500 W, the SSA3000X/X Plus/X-R/SVA1000X models may not be suitable due to DANL limitations when used with the recommended NRSC antenna.

The post Build FM NRSC masks for SIGLENT SSA3000X/SVA1015Xs using a Python script addition appeared first on Siglent.

• Configure the instrument span, RBW, and amplitude to capture the signals of interest
• Send “:CALC:MARK:PEAK:TABL ON”
• Send “:CALC:PEAK:TABL? “ to return the peak table data

Here, we show the displayed peak table and the data return using a VISA interface:

The post Programming Example: Return Peak Table Data with an SSA3000X Spectrum Analyzer appeared first on Siglent.

You can download the VI here: VISA_IDN.ZIP

In this example, the user can:

• Select the connected instruments from the VISA Resource List drop down menu:

NOTE: USB devices will automatically appear. For LAN connections, you will need to add the device. This is commonly done using NI Measurement and Automation Explorer (NI-MAX)

• Request the identification string once-per-press of the RUN button.

This sends the “*IDN?” identification query string to the instrument. The instrument then responds to the query with its identification string information. The identification string data will appear in the text box.

This code also uses the event structure connected to the value change of the RUN button to run once-and-only-once per keypress. This is a useful method of controlling code execution.

• Stop and exit upon pressing the STOP button

To run:

1. Connect instruments using a USB or LAN connection (see users manual for specific instrument details)
2. Power on instrument
3. Open LabVIEW and select the IDN.VI. This will open the VI front panel:

4. Select the instrument of interest from the VISA Resource drop down menu:

5. Press RUN on the LabVIEW VI menu strip to run the program:

6. Now, the “graph paper” background goes clear, indicating that the code is running. Now, you can press RUN in the VI Front Panel to execute the code:

The identification string should appear in the textbox:

7. Press STOP on the VI Front Panel to exit the code

The post Programming Example: Identification String (*IDN?) return with LabVIEW 2018 appeared first on Siglent.

But, like other spectrum analyzers, they are very sensitive and can be damaged easily, if the proper precautions are not followed.

The instruments have standard protection elements that includes a DC blocking capacitor and an automatic attenuator that help to prevent damage from low frequency and higher powered signals. There is even an audible and visible warning if the ADC (Analog-to-Digital Converter) overload.

In addition to this, adding external attenuation and protection can be useful in further preventing damage, especially when connecting to unknown sources such as antennas, transmitters, and LISNs.

One of our customers, Mr. Jeff Covelli (WA8SAJ), is a HAM (Amateur Radio Operator) who recently shared a very simple protection box that can be useful for keeping that sensitive front end functioning when connecting to unknown signal sources.

He uses it to help protect the input on his SIGLENT SDG1032X signal generator as well as his SSA3021X spectrum analyzer:

And he has a pretty impressive setup:

And here are the details:

At some point, I hope to characterize this setup and provide S11, S21 information.. but, if your signal is unknown, this will add an additional layer of protection when measuring an unknown signal for the “first time”.

The post DIY Spectrum Analyzer Input Protection appeared first on Siglent.

Some products do not have locations for cable lock connections.

In this case, we recommend using a special glue or physical attachment system to secure the cable to the case of the instrument.

Here is an example:

https://www.kensington.com/p/products/security/lock-anchor-points-accessories/security-slot-adapter-kit-for-ultrabook/

The post Secure products without K-lock slots appeared first on Siglent.

The VXI bus and subsequent software drivers form a convenient software API that can make remote control of instrumentation over LAN quite simple. In fact, it forms the basis of the TCPIP communications used in LXI format that is being implemented across the industry.

For more info on VXI, you can check out the VXI Consortium

VXI has a small installation size and is quite flexible.. especially when compared to VISA based applications. VISA is convenient and does allow for easy bus changes (from GPIB to USB with just a few lines of code), but it is also a large installation that isn’t always easy to use on machines that are not running Windows.

VXI has many flavors.. and can be used with many OS’ and can be used on many instruments that do not have “open sockets” on their LAN connection.

Here is a list of SIGLENT products that have LAN but do not have open sockets:

SDS2000

SDS2000X

SDS1000X/X+

SPD3000X/XE

In this note, we are going to show how to use VXI-11 with Python to control an instrument. This can be used with traditional OS’ like Windows but offer even more when coupled with Linux variants like those running on Rasberry Pis and other single board computers (SBCs).

Configuration

First, you will need to download a few programs..

• Python: https://www.python.org/downloads/release/python-2714/

NOTE: This technique works with version 2.x and 3.x.. in this example, we will use Python 2.7.14 for Windows 64 bit OS’

• Python VXI-11: https://github.com/alexforencich/python-vxi11

Once downloaded, you can add VXI-11 to your Python instance..

1. Open the command line program in Windows. You can find it by searching for “CMD” or by going to the Start Menu >  Windows System > Command Prompt as shown here:

2. In another window, find the location of the Python VXI-11 folder that was downloaded previously and find the path for setup.py. In this case, the path on my PC is shown as:

Now, you can click on the “address” to open the exact path:

Here, I suggest opening Notepad and “copy-paste” the path. It will make the transfer easier:

3. Change the directory in the Command line program to match the path from step 2:

Type “cd <PATH>” as shown:

4. Now, the directory has changed to match the path. You can run the setup.py file by typing “python setup.py install” as shown:

5. Close the Command Prompt

Test the installation

Now that everything has been installed, let’s test the communications link.

1. Connect the instrument to the LAN of the controlling computer and power it on

2. Check the IP address for the product (see the User’s Guide of the specific product for more info), In this case, I am using an SDS2000X oscilloscope. Here is the IP address information:

3. Now, start the Python shell. There are a few ways to start this application. In this case, you can find the Python folder in the Windows start folder.

Open IDLE (A Python GUI):

Now, click Run > Python Shell to open the shell:

4. Now, import the VXI11 library by typing “import vxi11”

5. Now, we can assign the variable “instr” to the instrument as shown:

6. Now, we can use the VXI Ask command to send the identification string (*IDN?), request the response, and print it to the screen:

The VXI11 library features a number of functions to handle writing and reading strings and other formats. You can use this technique to establish communications and control the instrument efficiently.

Click here to download a Python file of this example: PythonVXI11_IDN

The post Programming Example: Using VXI11 (LXI) and Python for LAN control without sockets appeared first on Siglent.

TEM cells are specialized hardware enclosures that can provide high electric fields and also do offer some shielding from environmental RF.

If you are having immunity issues, this note may provide some helpful information and guidance.

For more information, check out this link:

AN Immunity testing _Tekbox TEM Cell

The post Immunity testing with a Tekbox TEM cell appeared first on Siglent.

In this note, we are going to use the tracking generator (TG) function of a SIGLENT SVA1015 Spectrum Analyzer to test an unknown attenuator. The TG provides a sine wave signal with a known amplitude across a range of frequencies and we can measure the response of the device-under-test (DUT).

We also have a video here: Attenuator Verification Video

Hardware:

• SIGLENT SVA1015X Spectrum and Vector Network Analyzer*
• Qty 2 coaxial cables (N-type on one end for connection to the SVA, the other end should match your attenuator connections)
• Attenuator to test (note the connector types)
• Qty 1through, or barrel, adapter

*This method applies to the SIGLENT SSA3000X series as well

In this note, we are testing this attenuator:

Notice that it terminates in SMA connections.

So, we will need an SMA-to-SMA through adapter to properly test the attenuator:

Initial Steps:

1. Power on and warm up the analyzer

2. Connect a cable to the TG output of the analyzer

3. Connect a cable to the RF input of the analyzer

4. Set the frequency range of interest. In this case, we want to see the attenuator functionality across as wide a frequency range as possible. The SVA TG starts at 5 MHz and operates up to 1.5 GHz, so we can press FREQUENCY on the front panel (or display, as the SVA has a touch screen) and set this to 1.5 GHz:

Optional: You can change the TG amplitude if the -20 dBm default is not appropriate for your testing.

Normalize:

Normalization is a step that helps minimize measurement errors added by the cables, adapters, and connectors that are in the test circuit.

The process is simple: Connect all of the cabling and adapters required to test the device, in place of the device, use a high-quality through-adapter and start the test. The result will include the effects of the cabling and any adapters used. We can then “normalize” these effects by activating normalization on the instrument. This function subtracts the result of the sweep from itself, point-by-point and displays a new normalized curve. When we then add the device-under-test (DUT) to this circuit, we will directly see the effects. In this example, if the steps are executed properly, the normalized curve will show up as a line at 0 dB and we can continue.

1. Connect the TG output cable to the RF input cable using the SMA through adapter.

NOTE: To avoid damaging connections, grip the adapter and spin the hex cable end to tighten. Spinning the adapter can quickly damage connectors.

2. Enable the tracking generator (TG) output by pressing TG > TG ON

Here, you can see that the TG output amplitude is set to -20 dBm, and the measured power that we read on the RF measurement side is approximately -20 dBm. The line isn’t perfectly flat because of the effects of the cabling and adapters.

3. Enable Normalize by setting Normalize > ON

Remember that when we activate normalization, we are subtracting the measured curve from itself which results in a flat line at 0 dB. The normalized curve is now located at the top of the screen.

4. Adjust the graph so that you can observe the normalized curve by changing the Normal Ref Level:

Test the DUT:

1. Remove the through adapter from the TG output cable

2. Attach the DUT to the TG output cable

3. Attach the through adapter to the end of the DUT:

 NOTE: To avoid damaging connections, grip the adapter and spin the hex cable end to loosen. Spinning the adapter can quickly damage connectors.

4. Now, the displayed data represents the attenuators influence on the signal. Without the attenuator, we were reading 0 dB. Now, we are reading -10 dB. Therefore, this is a 10 dB attenuator.. with fairly flat response up to 1.5 GHz as shown:

The post Attenuator verification using a spectrum analyzer with a tracking generator appeared first on Siglent.