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C cf introduction to antenna

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Mobile communications is one of the communications fields that develop rapidly and energetically. The antenna builds the bridge between user terminals and base control devices. It is widely used in the mobile communications and the wireless access communication system. The rapid development of the antenna greatly promotes its technology innovation.
It is important to deeply grasp the knowledge of the antenna, which is useful to:
Install and maintain products.
Promote the network planning.
Chapter 1 Working Principle
Chapter 2 Classification
Chapter 3 Electrical Index
Chapter 4 Mechanical Index
When the conducting cable carries the alternating current, the electromagnetic wave radiation can be formed.
If two conducting cables are close, the directions of their current are opposite, and the electromotive force is counteracted. Thus the radiation becomes week.
If two conducting cables are open, the directions of their current are the same. Thus the radiation becomes strong.
When the length of the conducting cable is like the wavelength, the current on the cable will be enhanced. Thus the radiation becomes strong.
The straight conducting cable which can generate the strong radiation is called the dipole.
The pole whose two arms are of the same length (1/4 Wavelength) is called as dipole or half-wave-length dipole.

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C cf introduction to antenna

  1. 1. ISSUE 2.1
  2. 2. Mobile communications is one of the communicationsfields that develop rapidly and energetically. Theantenna builds the bridge between user terminals andbase control devices. It is widely used in the mobilecommunications and the wireless accesscommunication system. The rapid development of theantenna greatly promotes its technology innovation.It is important to deeply grasp the knowledge of theantenna, which is useful to:• Install and maintain products.• Promote the network planning.
  3. 3. TargetAfter learning the course, you canlearn the following of the antenna: Working principle Classification Electrical index and mechanicalindex
  4. 4. Chapter 1 Working PrincipleChapter 1 Working PrincipleChapter 2 ClassificationChapter 3 Electrical IndexChapter 4 Mechanical Index
  5. 5. Working Principle8 Lightning arresterMain feeder (7/8”)5 Feeder fixing clip6 Cabling Rack (Frame)4 Grounding device3 Weather-proof connection PVCmaterial , Insulation sealing tape,PVC insulation tape1 Adjusting bracketGSM/CDMABoard-likeantennaAntenna pole (φ50~114mm)2 Outdoor feeder9 Indoor super flexible jumper7 Cable-through windowMainequipmentof BTSDiagram of the base antenna andfeeder systemLocation and FunctionLocation and Function
  6. 6. Working Principle When the conducting cable carries the alternatingcurrent, the electromagnetic wave radiation can beformed. If two conducting cables are close, the directions oftheir current are opposite, and the electromotiveforce is counteracted. Thus the radiation becomesweek. If two conducting cables are open, the directions oftheir current are the same. Thus the radiationbecomes strong. When the length of the conducting cable is like thewavelength, the current on the cable will beenhanced. Thus the radiation becomes strong. The straight conducting cable which can generatethe strong radiation is called the dipole. The pole whose two arms are of the same length(1/4 Wavelength) is called as dipole or half-wave-length dipole.
  7. 7. Working PrincipleThe pole whose two arms are of the same length (1/4Wavelength) is called as dipole or half-wave dipole.Half-Wavelength DipoleHalf-Wavelength Dipole
  8. 8. Working PrincipleWhat is happen in these antennas?
  9. 9. Chapter 1 Working PrincipleChapter 2 ClassificationChapter 2 ClassificationChapter 3 Electrical IndexChapter 4 Mechanical Index
  10. 10. ClassificationDirectional antenna Omni-directional antennaBased on the Radiation DirectionBased on the Radiation Direction
  11. 11. Board-like antenna Cap-like antennaScourge-like antenna Paraboloid-like antennaBased on the FigureBased on the FigureClassification
  12. 12. Classification The electric field orientation of the radio wave is called the polarization. Vertical polarization means that the electric field orientation is upright to the terrestrial. Horizontal polarization means thatthe electric field orientation is parallel to the terrestrial. When the vertical polarization wave is received by the horizontal polarization antenna, the current cannot be produced.Receiving the wave is badly affected. The monopole antenna needs two main diversity antennas to enhance the receiving effectiveness. The dual-polarizedantenna, with the polarization of 45 angles, needs only one antenna.Polarization ModePolarization Mode
  13. 13. ClassificationBased on Polarization ModeBased on Polarization Mode
  14. 14. Chapter 1 Working PrincipleChapter 2 ClassificationChapter 3 Electrical IndexChapter 3 Electrical IndexChapter 4 Mechanical Index
  15. 15. Electrical Index
  16. 16. Electrical IndexOrientation of half-wavedipoleTop view Side-lookingOrientation of omni-directional antennaDiagram of DirectionsDiagram of DirectionsOrientation of directional antenna
  17. 17. Electrical Index The units of the antenna gain are dBi and dBd. dBi: Gain based on the isotropic radiator reference dBd: Gain based on the dipole reference The value difference between the two units is 2.15dB. Gain of antenna compared with dipole is denoted bydBd. Gain of antenna compared with isotropic radiator isdenoted by dBi.Antenna Gain
  18. 18. Electrical IndexDiagram of DirectionsDiagram of Directions How to read the direction? Horizontal Vertical Main lobe Minor lobe Front-to-back Nulls HPBW (Half Power Beam width)
  19. 19. Electrical Index Beam width, front-to-back rejection ratio, null filling, upperside lobe suppression
  20. 20. Electrical IndexMechanical down tiltElectrical down tiltMechanical Down Tilt andMechanical Down Tilt and Electrical Down Tilt
  21. 21. Electrical Index9.5 W80ohms50 ohmsForward: 10WBack: 0.5WVSWR: Stand Wave RatioReflect Index : rImport impedance : Za characteristic: Zbr=|Za - Zb| / |Za + Zb|VSWR = (1+|r|) / (1-|r|)RL(Return Loss)=20lg |r|Normal Value: VSWR<1.5dB ; RL(dB)<13.98dB
  22. 22. Chapter 1 Working PrincipleChapter 2 ClassificationChapter 3 Electrical IndexChapter 4 Mechanical IndexChapter 4 Mechanical Index
  23. 23. Mechanical Index Antenna input Antenna size Antenna weight Wind load Working temperature Humidity Thunderbolt protection 三防能力
  24. 24. Chapter 1 Working PrincipleChapter 2 ClassificationChapter 3 Electrical IndexChapter 4 Mechanical Index
  25. 25. Questions What are the types of the antennas by signal radiation?What are the types of the antennas by appearance? What are the main electrical indexes of the antenna? What are the main mechanical indexes of the antenna? What are the types of the distribution system?
  26. 26. Course Summary Working principle Classification Electrical index Mechanical indexSummarySummary

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