Determination of far-field antenna patterns from near-field measurements

In many cases, it is impractical or impossible to make antenna pattern measurements on a conventional far-field range; the distance to the radiating far field may be too long, it may be impractical to move the antenna from its operating environment to an antenna range, or the desired amount of pattern data may require too much time on a far-field range. For these and other reasons, it is often desirable or necessary to determine far-field antenna patterns from measurements made in the radiating near-field region; three basic techniques for accomplishing this have proven to be successful. In the first technique, the aperture phase and amplitude distributions are sampled by a scanning field probe, and then the measured distributions are transformed to the far field. In the second technique, a plane wave that is approximately uniform in amplitude is created by a feed and large reflector in the immediate vicinity of the test antenna. And in the third technique, the test antenna is focused within the radiating near-field region, patterns are measured at the reduced range, and then the antenna is refocused to infinity. Each of these techniques is discussed, and the various advantages and limitations of each technique are presented.

[1]  D. M. Kerns,et al.  Theory of diffraction in microwave interferometry , 1960 .

[2]  J. H. Richmond,et al.  A Modulated Scattering Technique for Measurement of Field Distributions , 1955 .

[3]  J. A. Carruthers,et al.  I. Indoor Measurement of Microwave Antenna Radiation Patterns by Means of a Metal Lens , 1950 .

[4]  C. Andrews.  Microwave Probes for Electric Fields Near Metal Surfaces , 1968 .

[5]  V. Galindo,et al.  Design of dual-reflector antennas with arbitrary phase and amplitude distributions , 1963 .

[6]  A. Ludwig,et al.  Near-field far-field transformations using spherical-wave expansions , 1971 .

[7]  D. Paris,et al.  Digital computer analysis of aperture antennas , 1968 .

[8]  G.H. Brown,et al.  General Considerations of Tower Antennnas for Broadcast Use , 1935, Proceedings of the Institute of Radio Engineers.

[9]  J. P. Shanklin.  Pattern Measurements of Large Fixed Antennas , 1955 .

[10]  V. Rumsey,et al.  Measurement of electric field distributions , 1955 .

[11]  H. A. Ecker,et al.  Illumination Equipment for Electromagnetic Radiation Hazard Research. , 1971 .

[12]  T. Taylor.  Design of line-source antennas for narrow beamwidth and low side lobes , 1955 .

[13]  P. Hannan,et al.  Microwave antennas derived from the cassegrain telescope , 1961 .

[14]  P. Potter.  Application of spherical wave theory to cassegrainian-fed paraboloids , 1967 .

[15]  H. A. Ecker,et al.  COMPACT RADAR REFLECTIVITY RANGES , 1968 .

[16]  H. Booker,et al.  The concept of an angular spectrum of plane waves and its relation to that of polar diagram and aperture distribution , 1950 .

[17]  R. Johnson,et al.  Compact range techniques and measurements , 1969 .

[18]  R. King,et al.  The loop antenna as a probe , 1964 .

[19]  T. Chu.  A note on simulating Fraunhofer radiation patterns in the Fresnel region , 1971 .

[20]  Richard C. Johnson,et al.  COMPACT ANTENNA RANGE TECHNIQUES , 1965 .

[21]  D. M. Kerns,et al.  Recent experimental results in near-field antenna measurements , 1970 .

[22]  David K. Cheng,et al.  On the simulation of Fraunhofer radiation patterns in the Fresnel region , 1957 .

[23]  E. Jull,et al.  An investigation of near-field radiatin patterns measured with large antennas , 1962 .

[24]  H. Brueckmann.  Antenna pattern measurement by satellite , 1963 .

[25]  R. Harrington.  Small Resonant Scatterers and Their Use for Field Measurements , 1962 .

[26]  J. T. Kennedy,et al.  The use of solar radio emission for the measurement of radar angle errors , 1962 .

[27]  Richard C. Johnson,et al.  IMPROVED POINT-SOURCE AND LINE-SOURCE COMPACT ANTENNA RANGES , 1967 .

[28]  J. H. Richmond,et al.  Probes for Microwave Near-Field Measurements , 1955 .

[29]  J. Brown,et al.  A theoretical analysis of some errors in aerial measurements , 1958 .

[30]  E. V. Jull,et al.  The estimation of aerial radiation patterns from limited near-field measurements , 1963 .

[31]  M. Fahey,et al.  Focused phased array measurements , 1973 .

[32]  S. Moseley,et al.  On-axis defocus characteristics of the paraboloidal reflector , 1955 .

[33]  Harry Allen Ecker.  Study of directivity optimization for linear antennas , 1965 .

[34]  Alfred Brian Pippard.  The hoghorn—an electromagnetic horn radiator of medium-sized aperture , 1946 .

[35]  E. Joy,et al.  Spatial sampling and filtering in near-field measurements , 1972 .

[36]  P. Clemmow,et al.  The plane wave spectrum representation of electromagnetic fields , 1966 .

[37]  J. R. Mentzer.  The Use of Dielectric Lenses in Reflection Measurements , 1953, Proceedings of the IRE.

[38]  R. Plonsey.  Surface Current Measurements with an Electric Probe , 1962 .

[39]  D. Paris,et al.  Probe compensated near-field measurements on a cylinder , 1973 .

[40]  J. Dyson.  Measurement of near fields of antennas and scatterers , 1973 .

[41]  D. M. Kerns.  Correction of near-field antenna measurements made with an arbitrary but known measuring antenna , 1970 .

[42]  H. L. Bassett,et al.  New Techniques for Implementing Microwave Biological-Exposure Systems , 1971 .

[43]  E. V. Jull,et al.  The prediction of aerial radiation patterns from near-field measurements , 1961 .

[44]  J. A. Carruthers,et al.  Diffraction Errors in an Optical Measurement at Radio Wavelengths , 1951 .

[45]  A.P. King,et al.  Microwave Antenna Measurements , 1947, Proceedings of the IRE.

[46]  A. L. Cullen,et al.  A new perturbation method for measuring microwave fields in free space , 1955 .

[47]  T W Kethley,et al.  Aerosol research in the Bioengineering Laboratory, Engineering Experiment Station, Georgia Institute of Technology. , 1967, Journal of the Air Pollution Control Association.

[48]  R. Petit,et al.  -. Near-Field Far-Field Transformations Using Spherical- Wave Expansions , 1971 .