1. Chapter 17. Antenna measurements

2. Contents Introduction Antenna ranges Radiation patterns
Gain measurements
Directivity measurements
Radiation efficiency
Impedance measurement
Current measurement
Polarization measurement
Scale model measurement

3. Introduction Far field pattern을 얻기 위해 이상적인 경우 입사파는 plane wave이다.
송수신 안테나 거리가 D2/λ (Fraunhofer zone) 이상이면 phase error는 22.5º 이하이다.
지면 반사, mast 반사가 없는 것이 이상적.
AUT (antenna under test) 를 receiver로 하는 것이 편리.

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

5. Elevated ranges
Slant ranges

6. Anechoic chamber

7. Compact ranges

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

11. Reflector Edge (rim) treatment

12. Quiet zone field distributions

13. 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. Cassegrain type

15. Near field scanner Rectangular surface Cylindrical surface
Spherical surface

19. Spherical coordinate for radiation pattern

27. Two antenna method

28. Three antenna method