- Ask a related questionWhat is a related question?A related question is a question created from another question. When the related question is created, it will be automatically linked to the original question.
Tool/software:
I would like to make sure that the component is compatible with my project.
in my project, I would like to apply a very fast sweeper across two channels: 2.4 GHz and 5.8 GHz.
I need to make sure that the component does provide output frequencies of 10 MHz to 15 GHz as stated in the datasheet.
furthermore, I would like to understand the full capabilities of the frequency hopping rate. What is the fastest frequency change that the component is capable of. Moreover, I need to know what is the possible bandwidth of the output signal. In the datasheet it is stated that the loop bandwidth is 285khz. Does it mean it’s the maximum bandwidth?
For example, In my project I would like to apply a sweep In the channel of 2.4 GHz(which is 80 MHz). and I need to go through the whole channel in 100 microseconds. The question is whether the component step change(frequency hopping) is fast enough for my requirements.
thanks very much for the help.
Hi Michel,
Copy the link here again: https://www.ti.com/lit/pdf/snau210
Yes, LMX2594 can support these sweeps but it would not be a linear sweep. This is because the VCO sweep range is 320MHz (2.4GHz) and 250MHz (5.8GHz), multiple VCO calibrations are required in the middle of the sweep.
Instead of getting linear sweep like below:
Because of VCO calibration, you will actually get this:
Thank you again, Noel, for your detailed response.
We still need a bit of clarification regarding the VCO sweep ranges and how they apply to our project. The sweeps we intend to perform are:
2.4 GHz to 2.485 GHz
5.725 GHz to 5.850 GHz
To clarify, we are not intending to hop between the 2.4 GHz band and the 5.8 GHz band. Instead, the sweeps will be applied separately within each band. Both ranges are significantly smaller than the stated VCO sweep ranges of 320 MHz at 2.4 GHz and 250 MHz at 5.8 GHz, as mentioned in your previous message.
We would like to understand the following:
What are the exact boundaries of the VCO ranges? For example, if the VCO range at 2.4 GHz is 320 MHz, does this mean it spans from 2.3 GHz to 2.62 GHz?
If the sweep we are performing (e.g., 2.4 GHz to 2.485 GHz) is entirely within the VCO range, will recalibration still be required? Or can we expect a fully linear sweep without interruptions?
Additionally, we noticed from the provided graph that even when the sweep is linear, the device appears to sweep 10 MHz in 200 microseconds, which translates to 100 kHz/µs. However, in our earlier inquiry, we asked if the device could sweep 80 MHz in 100 microseconds, and it was confirmed as possible(also we can see in the data sheet a similar graph that shows a sweep of 120 MHz in 100 micro seconds).
Could you clarify whether this is achievable with the LMX2594, and under what conditions?
Finally, is there another component similar to the LMX2594 that might better meet our requirements for fast, wideband frequency sweeping?
We greatly appreciate your continued support and insights!
