Gain reduction on measurement of distance and on sizes of test and probe antennas are discussed. We consider only the case of linear antenna with uniform field distribution. The analysis is based on time-domain (TD) physical optics (PO) method of field calculation . We show that in determining the level of the side lobe there are two competing effects: (i) the decrease in the amplitude of the signal in the direction of the side lobe and (ii) reducing the maximum signal level in the direction of zero-angle. We show the optimal measurement distance with respect to the acceptable small errors of antenna gain. It is shown that optimal relation β=b/a is about ~0.4 (a and b are the sizes of the antenna under test and the probe antenna). For this optimal relation, the well-known far-field distance criterion R0=2D2/λ can be reduced by 2 times (D is the diameters of the antenna under test and λ is wavelength). Note that when b is optimal, the errors in determining of the sidelobe levels are also small and do not exceed 0.5 dB.
2. Hacker, P. S. and H. E. Schrank, "Range distance requirement for measuring low and ultralow sidelobe antenna patterns," IEEE Transactions on Antennas and Propagation, Vol. 30, No. 5, 956-966, Sept. 1982.
3. Hansen, R. C., "Measurement distance effects on low sidelobe patterns," IEEE Transactions on Antennas and Propagation, Vol. 32, No. 6, 591-594, Jun. 1984.
4. Hansen, R. C., "Array pattern control and synthesis," Proc. IEEE, Vol. 80, 141-151, Jan. 1992.
5. Hansen, R. C., "Measurement distance effects on Bayliss difference patterns," IEEE Transactions on Antennas and Propagation, Vol. 40, No. 10, 1211-1214, Oct. 1992.
6. Bregains, J., F. Ares, and E. Moreno, "Effects of measurement distance on measurements of symmetrically shaped patterns generated by line sources," IEEE Antennas and Propagation Magazine, Vol. 45, No. 1, 106-109, Feb. 2003.
7. Bregains, J. C., F. Ares, and E. Moreno, "Measurement distance effects on Φ-symmetric shaped patterns generated by circular continuous apertures," IEEE Antennas and Propagation Magazine, Vol. 45, No. 5, 68-70, Oct. 2003.
8. Corona, P., G. Ferrara, and C. Gennarelli, "Measurement distance requirements for both symmetrical and antisymmetrical aperture antennas," IEEE Transactions on Antennas and Propagation, Vol. 37, No. 8, 990-995, Aug. 1989.
9. Orefice, M., M. A. Razzaq, and G. Dassano, "Sidelobe level correction for parabolic antennas radiation pattern measurements in quasi-far-field conditions," Electronics Letters, Vol. 49, No. 23, 1423-1425, ISSN 0013-5194, 2013.
10. Mentzer, J. R., Scattering and Diffraction of Radio Wave, Chapter 5, Pergamon, Elmsford, NY, 1955.
11. Rhodes, D. R., "On minimum range for radiation patterns," Proc. IRE, Vol. 42, 1048-1410, Sept. 1954.
12. Jull, E. V., "An investigation of near-field radiation patterns measured with large antennas," IEEE Transactions on Antennas and Propagation, Vol. 10, 363-369, 1962.
13. Uno, T. and S. Adachi, "Range distance requirements for large antenna measurements," IEEE Transactions on Antennas and Propagation, Vol. 37, 707-720, Jun. 1989.
14. Hu, M. K., "Near zone power transmission," IRE Nat. Conv. Rec., Pt. 8, 128-138, 1958.
15. Brown, J. and E. V. Jull, "The prediction of aerial radiation patterns from near-field measurements," Proc. IEE, Vol. 105B, 635-644, Nov. 1961.
16. Kim, J.-H. and H.-K. Choi, "Antenna radiation pattern measurement at a reduced distance," IEEE Transactions on Instrumentation and Measurement, Vol. 54, No. 2, 673-675, Apr. 2005.
17. Skulkin, S. P. and Y. E. Sorpov, "An analysis of range distance requirements for large antennas by the use of the pulse radiating characteristics of aperture," Proc. IEEE AP-S/URSI Symposium, 1758-1761, Newport Beach, USA, Jun. 1995.
18. Skulkin, S. P. and A. V. Sudaev, "The time domain analysis of range distance requirements for large antenna measurements," Proc. XXVth General Assembly URSI, 587, Lille, France, Aug. 1996.
19. Skulkin, S. P., "Transient fields of rectangular aperture antennas, in ultra-wideband, short-pulse electromagnetics,", C. E. Baum, L. Carin, A. P. Stone (eds.), Vol. 3, 57-63, Plenum, 1997.
20. Skulkin, S. P. and V. I. Turchin, "Transient fields of parabolic reflector antennas. in ultra-wideband, short-pulse electromagnetics,", C. E. Baum, L. Carin, A. P. Stone, Eds., Vol. 3, 81-87, Plenum, 1997.
21. Skulkin, S. P. and V. I. Turchin, "Transient fields of offset reflector," Ultra-Wideband, Short-Pulse Electromagnetics, P. D. Smith and S. R. Cloude (eds.), Vol. 5, 371-375, Springer, US, 2002.
22. Landau, L. D. and E. M. Lifshitz, The Classical Theory of Fields, 3rd Ed., 70, Pergamon Press, Oxford, 1971.