welljustin
Newbie level 3
location of modulation index in signal
Hallo,
I have a problem of the un-sufficient AM modulation index under large signal generated by RF signal generator.
The test setup is as follows:
I use HP33120A arbitrary waveform generator to create the digital baseband signal(2KHz) for the ASK modulation, and connect the output to the modulation input of the signal generator, HP8647A. And then I set the RF output as **MHz/100%AM. And when I try to measure the maximum power that the receiver can handle, the problem shows up. From the HP8591E spectrum analyzer, it seems that when the RF output power is higher than a threshold, like -20dBm, the AM modulation index will never be 100% again. The higher the power is, the less the modulation index is. And when the signal is weak, everything is ok.
I have checked the datasheet of the signal generator, unfortunately, I can not find the answer, and who can help me a little bit here ?
Thanks a lot in advance!
Hallo,
I have a problem of the un-sufficient AM modulation index under large signal generated by RF signal generator.
The test setup is as follows:
I use HP33120A arbitrary waveform generator to create the digital baseband signal(2KHz) for the ASK modulation, and connect the output to the modulation input of the signal generator, HP8647A. And then I set the RF output as **MHz/100%AM. And when I try to measure the maximum power that the receiver can handle, the problem shows up. From the HP8591E spectrum analyzer, it seems that when the RF output power is higher than a threshold, like -20dBm, the AM modulation index will never be 100% again. The higher the power is, the less the modulation index is. And when the signal is weak, everything is ok.
I have checked the datasheet of the signal generator, unfortunately, I can not find the answer, and who can help me a little bit here ?
Thanks a lot in advance!