1 / 12

AM Modulators, SSB

AM Modulators, SSB. Analog and Digital Communications Autumn 2005-2006. AM – Power Calculations. Lets calculate power in carrier and sidebands:. (in one sideband). AM – Power Calculations. At least 50% power is wasted in carrier. USB. LSB. LSB. USB. DSB-SC or Simple DSB.

gavan
Télécharger la présentation

AM Modulators, SSB

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. AM Modulators, SSB Analog and Digital Communications Autumn 2005-2006 CS477: Analog and Digital Communications

  2. AM – Power Calculations Lets calculate power in carrier and sidebands: (in one sideband) CS477: Analog and Digital Communications

  3. AM – Power Calculations At least 50% power is wasted in carrier CS477: Analog and Digital Communications

  4. USB LSB LSB USB DSB-SC or Simple DSB CS477: Analog and Digital Communications

  5. ( is power in one sideband) DSB – Power Calculations How does AM compare with DSB? (Criteria for good modulation!) CS477: Analog and Digital Communications

  6. Power Calculations For DSB-SC or DSB: For DSB+C or AM: (100% modulation) CS477: Analog and Digital Communications

  7. Information signal is Tone Modulation For DSB-SC or DSB: For DSB+C or AM: CS477: Analog and Digital Communications

  8. Tone Modulation For DSB-SC or DSB: For DSB+C or AM: CS477: Analog and Digital Communications

  9. Modulators • Product modulators • Require analog multipliers • Variable trans-conductance multipliers • Hall effect devices • Hard to build • Generally limited by low power and low frequencies • Modulators based on filtering undesired frequencies • Square-law and balanced modulators • Ring modulator • Switching modulator • Avoid heavy filtering by not generating higher frequencies CS477: Analog and Digital Communications

  10. USB LSB LSB USB Islands are not symmetric around SSB-AM First consider DSB-SC Pass it through an “SSB filter” CS477: Analog and Digital Communications

  11. (Transmission BW is twice the signal BW) SSB and DSB Comparison For DSB: For SSB: CS477: Analog and Digital Communications

  12. Information signal is Tone Modulation: SSB & DSB For DSB-SC or DSB: For USSB: For LSSB: CS477: Analog and Digital Communications

More Related