[muhammad saqlainParticipant]

Dear,this setup is looking incorrect.100GHz sine wave signal conversion to digital using ADC and at the end DAC after LPF????.i advise you to read some basics articles of D-RoF concept.

[muhammad saqlainParticipant]

ok.Match your input mapped data (baseband signal)and output signal (in case after LPF) using dual port oscilloscope.If there is any delay or DC shift in output baseband signal,try to remove it and hopefully this middle line would be removed.

[muhammad saqlainParticipant]

Dear mohamed,i have a few questions about D-RoF.1)digitization of 5GHz RF signal and data rate of 5 Gb/s (simple NRZ encoding technique)requires sample rate ???
2) simulation setup is sequential,start with 1.RF signal (5GHz,amplitude=1,bias and phase=0) followed by ADC (sampling rate > 10GHz,resolution =4-8 bits.Data stream of 5Gb/s is mapped on NRZ signal genrator and this moudule connected to Directly modulated laser.Move on,output of ADC and directly modulated laser is connected to MZM followed by PIN diode,DAC (same specifications like ADC),LPF and BER analyzer.
2)i couldn’t find a BER or even a acceptable eye diagram.
Looking forward to constructive outcome discussion.
Regards,
Muhammad Saqlain

[muhammad saqlainParticipant]

let me explain the “ROLE of MIXER” the output would be like (F1+F2 and F1-F2) F1 and F2 are RF signal and Local oscillator frequencies respectively.output of photo-detector (PD) is 60GHz mm-wave signal(RF) with 7Gbps data rate and know the point is how to down convert this signal let say 5GHz.how to down convert it according to mixer basic operating principle.

[muhammad saqlainParticipant]

dear jawad,i am asking about the electrical mixer concept and i know the beating process.and above received signal at 60GHz after PD is achieved by hetrodying two free lasers.

[muhammad saqlainParticipant]

find the missed attachment from the trailing post.

Attachments:

1. 

   1-a.png
   

2. 

   2-a.png
   

[muhammad saqlainParticipant]

Dear Mohamed,i share my simulation result.please see the attachment(snapshots) one by one start from 1) photo-diode output 2)output of electrical multiplier (supposed to be electrical mixer),this multiplier is driven by 60GHz sinusoidal signal and one input from photo-diode.I look forward to your valuable comments to clear it whether it is working like a “ELECTRICAL MIXER”!!! .

[muhammad saqlainParticipant]

ok dear Mohamed.

[muhammad saqlainParticipant]

Ok i try but in my opinion, electrical multiplier does not have the same characteristics of electrical mixer.

[muhammad saqlainParticipant]

Thank you so much for your expert opinion and every time i learn more technical things from you.Yeah it is logical if we use random generator.

[muhammad saqlainParticipant]

Thank you for the reply.sometime i get the worse BER value =<10-2 and this value changes with every run(slightly), i mean BER is not stable and unable to get a reasonable BER value.Please attached herewith the block diagram for more understanding.I look forward to your valuable suggestion.

Attachments:

1. 

   Capture.png
   

[muhammad saqlainParticipant]

Dear Zulfiqar,i still have not started work on digitization.I will start simulation in few days and will be in better position to explain you the use of ADC and DAC components in simulation.

[muhammad saqlainParticipant]

thank you.

[muhammad saqlainParticipant]

Thank you Eric.

[muhammad saqlainParticipant]

Ok let me check it.Thanks