1 / 16

Course: Digital Communication and Coding Professor: Dr. Tareq AlNafouri

A QPSK Modulator Using Microwave Couplers and Switches for Satellite Transmitter and Its Performance Analysis. Course: Digital Communication and Coding Professor: Dr. Tareq AlNafouri Presented By: Farhan Abdul Ghaffar. QPSK MODULATION. INTRODUCTION WHY QPSK MODULATION?

avari
Download Presentation

Course: Digital Communication and Coding Professor: Dr. Tareq AlNafouri

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. A QPSK Modulator Using Microwave Couplers and Switches for Satellite Transmitter and Its Performance Analysis Course: Digital Communication and Coding Professor: Dr. Tareq AlNafouri Presented By: Farhan Abdul Ghaffar

  2. QPSK MODULATION • INTRODUCTION • WHY QPSK MODULATION? REMOTE SENSING PURPOSES X BAND 8 GHz to 12 GHz

  3. DESIGN OF THE MODULATOR

  4. THEORY OF THE MODULATORCIRCUIT ELEMENTS • MICROWAVE COUPLERS POWER DIVISION PHASE SHIFT S PARAMETERS • HIGH SPEED MESFET SWITCHES

  5. MICROWAVE COUPLERS • WILKINSON DIVIDER • THREE PORT ELEMENT EQUAL POWER DIVISION S21 = S31= -3dB NO PHASE SHIFT S21= S31

  6. BRANCH LINE HYBRID COUPLER • FOUR PORT ELEMENT EQUAL POWER DIVISION S21 = S31= -3dB QUADRATURE PHASE SHIFT S31- S21 = 90

  7. RAT RACE COUPLER • FOUR PORT ELEMENT EQUAL POWER DIVISION S23=S13= -3dB 180 PHASE SHIFT S23- S13= 180

  8. STRUCTURE and WORKING

  9. TESTING AND MEASUREMENT • DATA RATE = 160Mbps • PHASE IMBALANCE = 0.4 • AMPLITUDE IMBALANCE < 1% • EVM = 0.75%

  10. PERFORMANCE ANALYSIS • AMPLITUDE IMBALANCE • PHASE IMBALANCE • ERROR VECTOR MAGNITUDE

  11. EVM OF MODULATOR WITH AMPLIFIERS • EVM OF THE TRANSMITTER < 8%

  12. EVM vs. BER • To keep the value of EVM minimum we need S parameters to be as optimized as possible.

  13. EVM and SNR • Lesser EVM will give greater SNR and lesser Probability of Error

  14. HARDWARE OF THE MODULATOR

  15. Q & A Session

More Related