Hi team,
1. The starting frequency is 14G and the sweep bandwidth is 60M. The normal sweep configuration is as follows:
2. The starting frequency is changed to 14.06G, and the sweep bandwidth is 60M. It is unable to sweep normally. The configuration is as follows
Why can't it work normally after changing the starting frequency?
Best Regards,
Amy Luo
Hi Amy,
The first thing I would try is to make the Ramp Limits range much bigger than the ramp frequency range. For example:
Would you also ask the customer to provide their VCO setting?
The sweep frequency setting of 14.06G-14.12G is shown in the figure above.
Customer feedback said:
During debugging 11.999G-12.30G frequency sweep in these two days, it is found that it cannot be realized. Guess whether it is related to the N value of PLL? Since the integer part of the N value of 11.999G is 77 and the integer part of the N value when the frequency is greater than 12G is 78, the phenomenon of abnormal frequency sweeping will occur when the N value changes in the frequency sweeping state.
Hi Amy,
Between 11.999G and 12.3GHz, frequency ramp range is about 300MHz. A 300MHz linear ramp is not possible with this device, multiple VCO calibrations are needed in order to bring the VCO to the desired frequency. The following settings are suggested. whenever the amount of frequency ramp reaches 50MHz, a VCO calibration will be automatically performed. We need to reserve some time for the calibration. A min. of 50µs is suggested.
Hi Amy,
Customer's VCO setting is ok, do they still have problem if they extend the ramp limits?
