1. 1 EMLAB Chapter 17. Antenna measurements

2. 2 EMLAB Contents 1.Introduction 2.Antenna ranges 3.Radiation patterns 4.Gain measurements 5.Directivity measurements 6.Radiation efficiency 7.Impedance measurement 8.Current measurement 9.Polarization measurement 10.Scale model measurement

3. 3 EMLAB Introduction 1.Far field pattern 을 얻기 위해 이상적인 경우 입사파는 plane wave 이다. 2. 송수신 안테나 거리가 D 2 /λ (Fraunhofer zone) 이상이면 phase error 는 22.5º 이하이 다. 3. 지면 반사, mast 반사가 없는 것이 이상적. 4.AUT (antenna under test) 를 receiver 로 하는 것이 편리.

4. 4 EMLAB 1.Reflection ranges 2.Free space range ① Elevated (outdoor) ② Slant (outdoor) ③ Compact (indoor) ④ Anechoic (indoor) ⑤ Near field (indoor) 2. Antenna ranges

5. 5 EMLAB Elevated ranges Slant ranges

6. 6 EMLAB Anechoic chamber

7. 7 EMLAB Compact ranges

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9. 9 1.Aperture blockage 2.Direct feed through from the source to the receiver. 3.Diffraction from the edges Compact range 단점

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11. 11 EMLAB Reflector Edge (rim) treatment

12. 12 EMLAB Quiet zone field distributions

13. 13 EMLAB Compact range system :Dual parabolic cylinders Dual parabolic cylinder compact range collimates the field in one plane with the first reflector and then collimated the field in the orthogonal plane with the second reflector

14. 14 EMLAB Cassegrain type

15. 15 EMLAB Near field scanner Rectangular surface Cylindrical surface Spherical surface

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19. 19 EMLAB Spherical coordinate for radiation pattern

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27. 27 EMLAB Two antenna method

28. 28 EMLAB Three antenna method

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