Distorted Reflector Antennas: Analysis of Radiation Pattern and Polarization Performance

Surface distortions change the radiation characteristics of reflector antennas. Using functional calculus, radiation integral is analyzed, and the first variational derivative (VD) of the radiation field with respect to surface profile is extracted. The VD can show the radiation pattern sensitivity to surface distortion. All formulations are based on the physical optics approximation. The final formula for VD depends only on the original undistorted antenna parameters, so it can be used for all types of distortions. It has been shown that the formulations are more general than those in previous works. Different polarization states of feed antenna are studied, and VD amplitudes are plotted to depict the regions that have greater effects on the main-lobe and the first few side-lobes levels. Some periodic, aperiodic, and local distortion profiles are considered, and the exact and approximated distorted patterns are compared to check the accuracy of the presented procedure.

[1]  Y. Rahmat-Samii,et al.  Characterization of effects of periodic and aperiodic surface distortions on membrane reflector antennas , 2005, IEEE Transactions on Antennas and Propagation.

[2]  Yahya Rahmat-Samii,et al.  An efficient computational method for characterizing the effects of random surface errors on the average power pattern of reflectors , 1983 .

[3]  Byung-Sung Kim,et al.  Computation of the average power pattern of a reflector antenna with random surface errors and misalignment errors , 1996 .

[4]  J. Ruze.  Antenna tolerance theory—A review , 1966 .

[5]  Y. Rahmat-Samii.  Effects of deterministic surface distortions on reflector antenna performance , 1985 .

[6]  Paolo Rocca,et al.  Interval Arithmetic for Pattern Tolerance Analysis of Parabolic Reflectors , 2014, IEEE Transactions on Antennas and Propagation.

[7]  P. Goldsmith,et al.  Analysis of active surface reflector antenna for a large millimeter wave radio telescope , 1994 .

[8]  R. Langley,et al.  Wave scattering from error-compensating secondary reflectors , 1979 .

[9]  Y. Rahmat-Samii,et al.  Subreflector shaping for antenna distortion compensation: an efficient Fourier-Jacobi expansion with GO/PO analysis , 2002 .

[10]  Hong Bao,et al.  Sensitivity Analysis of Reflector Antennas and Its Application on Shaped Geo-Truss Unfurlable Antennas , 2013, IEEE Transactions on Antennas and Propagation.

[11]  B. S. Westcott,et al.  Dual-reflector synthesis based on analytical gradient-iteration procedures , 1995 .

[12]  A. Ludwig.  The definition of cross polarization , 1973 .

[13]  Y. Rahmat-Samii,et al.  A generalized diffraction synthesis technique for high performance reflector antennas , 1995 .

[14]  R. J. Bastian,et al.  An approximation of the radiation integral for distorted reflector antennas using surface-error decomposition , 1997 .

[15]  S. Ghobrial.  Axial cross polarization in reflector antennas with surface imperfections , 1980 .

[16]  Reflector sidelobe degradation due to random surface errors , 1986 .

[17]  D. Morris,et al.  Repetitive radio reflector surface deformations , 2005, IEEE Transactions on Antennas and Propagation.

[18]  S. V. Hoerner,et al.  Gravitational deformation and astigmatism of tiltable radio telescopes , 1975 .

[19]  S. von Hoerner.  Strong coma lobes from small gravitational deformations , 1980 .

[20]  B. Duan,et al.  Effects of Nonuniform Surface Errors Along the Radius on Reflector’s Radiation Characteristic and Its Quality Evaluation , 2015, IEEE Transactions on Antennas and Propagation.

[21]  Yahya Rahmat-Samii,et al.  Reflector Antenna Developments: A Perspective on the Past, Present and Future , 2015, IEEE Antennas and Propagation Magazine.

[22]  Jingli Du,et al.  Surface Configuration Design of Cable-Network Reflectors Considering the Radiation Pattern , 2014, IEEE Transactions on Antennas and Propagation.

[23]  B.Y. Duan,et al.  Reflector Antenna Distortion Analysis Using MEFCM , 2009, IEEE Transactions on Antennas and Propagation.

[24]  M. C. Bailey,et al.  A surface distortion analysis applied to the hoop/column deployable mesh reflector antenna , 1989 .

[25]  Axial cross polarization in reflector antennas with surface errors of large correlation diameter , 1983 .

[26]  K. K. Chan,et al.  Surface-current analysis of distorted reflector antennas , 1981 .

[27]  R.P. Corkish.  A survey of the effects of reflector surface distortions on sidelobe levels , 1990, IEEE Antennas and Propagation Magazine.

[28]  Carey M. Rappaport,et al.  Reflector antenna distortion determination: An iterative‐field‐matrix solution , 2008 .

[29]  Limitations on reflector antenna gain by random surface errors, pointing errors, and the angle-of-arrival jitter , 1990 .