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Antennas Module 10B

Antennas Module 10B. Based on Cisco Wireless Material. Overview.

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Antennas Module 10B

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  1. AntennasModule 10B Based on Cisco Wireless Material CCRI J. Bernardini

  2. Overview This module will cover basic antenna theory, including directional and omnidirectional antenna selection. After discussing antenna theory and types of antennas, cables, connectors and accessories for antennas will be discussed. Additionally, important antenna design considerations, such as link engineering, path planning, and installation are also discussed. CCRI J. Bernardini

  3. Learning Objectives • Define how an antenna is used to propagate an RF signal. • Define basic facts of EIRP. • Define facts on FCC regulations for UNII-1, UNII-2 and UNII-3. • Identify what an isotropic antenna is and why it is used as a reference for other antennas. • Identify Cisco Aironet antennas, their coverage patterns, and the proper polarization of each antenna. CCRI J. Bernardini

  4. Key terms • Lobes • Directional • Omnidirectional • Beamwidth • Bandwidth • Polarization • Vertical (Elevation) • Horizontal (Azimuth) • Diversity • Plane (H and E) • (H-Magnetic Field, E-Electric Field) CCRI J. Bernardini

  5. Definition of Terms • dB- Decibel- Ratio of one value to another • dBx where x = • m = compared to 1 milliwatt (0 dBm=1 mW) • i = compare to isotropic antenna • d = compared to dipole antenna • w = compared to 1 watt (0 dBw = 1 watt) CCRI J. Bernardini

  6. Cisco Aironet 802.11b Antennas • FCC requires that ALL antennas sold by a spread spectrum vendor be certified with the radio they are to be sold with • All Cisco Aironet 802.11b supplied cables, RF devices and antennas have reverse polarity TNC (RP-TNC) connectors • Cisco Aironet supplied antennas meet all FCC rules • Wide variety of 802.11b antennas for most applications CCRI J. Bernardini

  7. Cisco Aironet 802.11a Antennas • FCC requires that all radios utilizing the UNII-1 Band (5.15 GHz – 5.25 GHz) must have non-removable or integrated antennas • FCC allows radios utilizing the UNII-2 Band (5.25 GHz – 5.35 GHz) to have external or removable antennas • The Cisco Aironet 802.11a radios utilize both UNII-1 and UNII-2 bands, therefore cannot have external or removable antennas • Cisco 802.11a antennas are integrated into the radio module • Cisco 1400 radios utilize UNII-3 bands, therefore have external or removable antennas CCRI J. Bernardini

  8. Antenna Concepts • Directionality • Omni (360º coverage) directional • Directional (limited range of coverage) • Gain • Measured in dBi and dBd (0 dBd = 2.14 dBi) • More gain means more coverage - in certain directions • Polarization • Antennas are used in the vertical polarization CCRI J. Bernardini

  9. Antenna Issues (cont.) • Antennas have gain in particular directions • Direction other than the main intended radiation pattern, are typically related to the main lobe gain CCRI J. Bernardini

  10. Antenna Gain • If the gain of an antenna goes up, the coverage area or angle goes down • Coverage areas or radiation patterns are measured in degrees • Angles are referred to as beamwidth • Horizontal measurement • Vertical measurement CCRI J. Bernardini

  11. Antenna Theory • A theoretical isotropic antenna has a perfect 360º vertical and horizontal beamwidth • This is a reference for ALL antennas CCRI J. Bernardini

  12. Side View (Vertical Pattern) Vertical Beamwidth New Pattern (with Gain) Top View (Horizontal Pattern) Antenna Theory- Dipole • Energy lobes are ‘pushed in’ from the top and bottom • Higher gain • Smaller vertical beamwidth • Larger horizontal lobe • Typical dipole pattern CCRI J. Bernardini

  13. High Gain Omni-Directionals • More coverage area in a circular pattern • Energy level directly above or below the antenna will become lower CCRI J. Bernardini

  14. Side View (Vertical Pattern) Top View (Horizontal Pattern) Directional Antennas • Lobes are pushed in a certain direction, causing the energy to be condensed in a particular area • Very little energy is in the back side of a directional antenna CCRI J. Bernardini

  15. FCC Part 15 Antenna Requirements • 802.11b antenna • Must use a unique, or proprietary connector • Cisco Aironet products use RP-TNC connector • Part 15 standards • Approved antenna may exceed • Exceeding may lead to interference problems • Penalties could result in fines • FCC standards apply to Part 15 users in the United States • Different countries will have similar standards CCRI J. Bernardini

  16. 2.4 GHz EIRP Rules for FCC Governed Areas • Point-to-Multipoint • FCC allows increasing the gain of an antenna/cable system if the transmitter power is reduced below 30 dBm in a 1:1 ratio • Reduce Transmit Power below maximum of 30 dBm by 1 dBm and increase antenna/cable system gain by 1dBi • Point-to-Point • Maximum of 36 dBm EIRP • Installations – 30 dBm maximum transmitter power with 6 dBi in gain attributed to antenna and cable combination • FCC allows exceeding the 36 dBm EIRP in Point-to-Point installations using the 3:1 rule • Reduce Transmit Power below maximum of 30 dBm by 1 dBm and increase antenna/cable system gain by 3 dBi CCRI J. Bernardini

  17. 2.4 GHz EIRP Rules for FCC Governed Areas (cont.) Point-to-Multipoint Transmitter Power Transmitter dBm Maximum Gain EIRP 6 dBi 36 dBm FCC Maximum 30 dBm 1 Watt 36 dBm Cisco Maximum 16 dBi 100 mW 20 dBm The above values reflect the 1:1 rule Point-to-Point Transmitter Power Transmitter dBm Maximum Gain EIRP 6 dBi 36 dBm FCC Maximum 30 dBm 1 Watt 56 dBm Cisco Maximum 36 dBi 100 mW 20 dBm The above values reflect the 3:1 rule CCRI J. Bernardini

  18. 2.4 GHz EIRP Rules for ETSI Governed Countries • Currently ETSI stipulates a maximum of 20 dBm EIRP on Point-to-Multipoint and Point-to-Point installations –17 dBm maximum transmitter power with 3 dBi in gain attributed to antenna and cable combination • Professional installers are allowed to increase the gain of an antenna/cable system if the transmitter power is reduced below 17 dBm in a 1:1 ratio • Reduce Transmit Power below maximum of 17 dBm by 1 dBm and increase antenna/cable system gain by 1 dBi CCRI J. Bernardini

  19. 2.4 GHz EIRP Rules for non-FCC Governed Bodies Governing bodies with 20 dBm ceiling on EIRP: ETSI, France/Singapore, Israel, Mexico Point-to-Multipoint and Point-to-Point Transmitter Power Transmitter dBm Maximum Gain EIRP 3 dBi 20 dBm Gov. Body Maximum 17 dBm 50 mW 2.2 dBi 19.2 dBm 50 mW Cisco Integrated Antennas 17 dBm Reduced TX Power 20 dBm 30 mW 15 dBm 5 dBi Reduced TX Power 20 mW 20 dBm 13 dBm 7 dBi 5 mW 7 dBm 13 dBi Reduced TX Power 20 dBm Reduced TX Power 1 mW 0 dBm 20 dBm 20 dBi The above values reflect the 1:1 rule CCRI J. Bernardini

  20. 802.11a and FCC 5 GHz Specifications • FCC regulations for UNII-1 and UNII-2 • UNII-1 • FCC max 50 mW • 802.11a max 40 mW • With max 6 dBi antenna gain • 802.11a max of 40 mW complies with all countries except Singapore (20 mW) • UNII-2 • FCC max 250 mW • 802.11a max 200 mW CCRI J. Bernardini

  21. FCC Rules for 802.11a - Antennas • FCC requires that all radios utilizing the UNII-1 Band (5.15 GHz – 5.25 GHz) must have non-removable or integrated antennas • FCC allows radios utilizing the UNII-2 Band (5.25 GHz – 5.35 GHz) to have external or removable antennas • FCC requires radios operating in both UNII-1 and UNII-2 bands must comply with antenna rules regulating UNII-1 band (including indoor use only) • The Cisco Aironet 802.11a radios utilize both UNII-1 and UNII-2 bands, therefore cannot have external or removable antennas and must be used indoors only • Cisco 802.11a antennas are integrated into the radio module CCRI J. Bernardini

  22. 2.4 GHz Omni-Directional Antennas • 2 dBi Dipole "Standard Rubber Duck" CCRI J. Bernardini

  23. 2.4 GHz Omni-Directional Antennas • 5.2 dBi Mast Mount Vertical CCRI J. Bernardini

  24. 2.4 GHz Omni-Directional Antennas • 5.2 dBi Ceiling Mount CCRI J. Bernardini

  25. 2.4 GHz Omni-Directional Antennas • 5.2 dBi Pillar Mount Diversity CCRI J. Bernardini

  26. 2.4 GHz Diversity Omni-Directional Antennas • 2 dBi Diversity Omni-Directional Ceiling Mount CCRI J. Bernardini

  27. 2.4 GHz Omni-Directional Antennas • 12 dBi Omni-Directional (Outdoor only) CCRI J. Bernardini

  28. 5 GHz Omni-Directional Antennas • 9 dBi omni (Vertical polarization) CCRI J. Bernardini

  29. 5 GHz Omni-Directional Antennas • 9.5 dBi sector (H or V polarization) CCRI J. Bernardini

  30. 2.4 GHz Diversity Antennas • 6.5 dBi Diversity Patch Wall Mount – 55 degree CCRI J. Bernardini

  31. 2.4 GHz Directional Antennas (cont.) • 6 dBi Patch Antenna – 65 degree CCRI J. Bernardini

  32. 2.4 GHz Directional Antennas (cont.) • 8.5 dBi Patch Antenna – 60 degree CCRI J. Bernardini

  33. 2.4 GHz Directional Antennas (cont.) • 13.5 dBi Yagi Antenna – 25 degree CCRI J. Bernardini

  34. 13.5 dBi Yagi Antenna—Inside view CCRI J. Bernardini

  35. 2.4 GHz Directional Antennas (cont.) • 21 dBi Parabolic Dish Antenna – 12 degree CCRI J. Bernardini

  36. 5 GHz Omni-Directional Antennas • 28 dBi dish (H or V polarization) CCRI J. Bernardini

  37. 5 GHz Integrated Antenna • Innovative 5 GHz Combo Antenna: • Wall Mount: Fold antenna flat against access point housing for 6 dBi gain patch antenna • Ceiling Mount: Fold antenna out at a 90° angle for 5 dBi gain omni antenna In 6 dBi patch position In 5 dBi omni position CCRI J. Bernardini

  38. 5 GHz Radiation Pattern CCRI J. Bernardini

  39. Cisco Aironet 1100 Series Internal View 2.2 dBi Omni-Directional Diversity Antennas Mini-PCI Radio • Option 1: 802.11b CCRI J. Bernardini

  40. Cisco Aironet 1100 Series Antenna Details Cone of reduced coverage Sphere of influence Sphere of influence Cone of reduced coverage CCRI J. Bernardini

  41. Cisco Aironet 1100 Series Antenna Details (cont.) H-Plane Pattern E-Plane Pattern Floor Top View Side View CCRI J. Bernardini

  42. 2.4 GHz Accessories CCRI J. Bernardini

  43. RP-TNC Connectors CCRI J. Bernardini

  44. Lightning Arrestor • Designed to protect LAN devices from static electricity and lightning surges that travel on coax transmission lines • RP-TNC connectors used on all Cisco Antennas To Antenna Lug Lockwasher Nut Ground Wire From RF Device CCRI J. Bernardini

  45. Lightning Arrestor CCRI J. Bernardini

  46. Path Considerations • Radio line of sight • Earth bulge • Fresnel zone • Antenna and cabling • Data rate CCRI J. Bernardini

  47. Line of sight! Line of Sight • The following obstructions might obscure a visual link: • Topographic features, such as mountains • Curvature of the Earth • Buildings and other man-made objects • Trees CCRI J. Bernardini

  48. Longer Distances • Line of Sight disappears at 6 miles (9.7 Km) due to the earth curve CCRI J. Bernardini

  49. Fresnel Zone Fresnel Zone CCRI J. Bernardini

  50. Improving Fresnel Effect Raise the antenna New structure Existing structure Different mounting point Remove trees CCRI J. Bernardini

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