Can bode plot operation be automated when testing on bench?

Bode plots require several order of frequency signal to be input to a DUT and the output be obtained and then doing division of output by input to find gain for all input-output combinations.

Is there a device that is usually used to plot bode plots for physical on bench testing?

A scope can only measure a signal while a signal generator can only generate a signal. Thus, there is no way to plot a bode plot on a scope automatically as this requires that the scope and the signal generated communicate with each other, or atleast that a third device perhaps a compuer via serial port communicates with both the scope and the signal generator and gather the input-output data pairs and internally generates the bode plot.

This question is with reference to on bench testing of designed analogue filters.

Use Network Analyzer, if you need both magitude and phase responses.

I think a better question would be, how to do it without spending over $10,000.00 USD.

https://www.sdr-kits.net/

Relative cheap.

matrixofdynamism said:

A scope can only measure a signal while a signal generator can only generate a signal.

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Show me instruments you have.

Vendor Name such as Keysight, Textronix
Product Name such 8753E
External Interface such as LAN, USB, GPIB, Parallel, Serial.

In the 70's I used the scope to drive an FM generator with a triangle wave or use the X sweep out signal ( but retrace can cause BPF ghost errors ) but then the scales were linear. Then I calibrated the centre frequency and span. Thus made it easy to tune filter frequency, Q or double tuned BPF. If I wanted more flexibility I used Ch1 out to condition the sweep signal and displayed the filter out on Channel 2 as all scopes then had Ch1 out on the back which I fed to the FM gen.

If your filter is limited to say 50kHz then you can use a PC with Audacity to calibrate a filter in a LOG-LOG display from 1 to > 6 decades . You create the log sxeeep signal and use audio out then impedance match to your filter e.g. source ~0 , 50, 600 Ohm etc. and then use AUX input to record the signal and tools Analyze Spectral analysis on the results...

You can even design any active filter response, parametric Q, 1/3 octave bands etc. YOu can choose any signal source like FM, AM, random noise, white, pink, brown etc. It may even do phase shift.

All free software. But it might take some effort to make it into a BODE plotter with the correct loop interface and calibration.

The "thanks helped me" button is gone so pancho and sunnyskyguy thanks for your help.

Is there a device that is usually used to plot bode plots for physical on bench testing?

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It really depends on the degree of automation, and how deep your pockets are.
For me, I bought an antique HP3575A gain phase meter, digital readout of relative phase and db gain (or loss) from 1Hz to 13Mhz between two channels.
From memory about $180.00 on e-bay.

It does not plot anything, you still need a pencil and paper to write down the figures, and you need to drive the signal generator. But its pretty convenient and low cost, and quite sufficient for the very occasional Bode plot.

"I bought an antique HP3575A gain phase meter". Helped me.

I saw a video from w2aew on youtube (He really knows how to teach electronics).

Basically, in a video where he expounded the topic of miller affect and its mitigation using the classic cascode configuration mmmmmm, he set the signal generator to something called "sweep" mode between a minimum and maximum frequency value. He then used the scope to find the cut-off frequency. The scope scale is obviously linear, but still this method can be used to get some idea of the frequency response without having extra equipment.