Yu. I. Choni – Ph.D. (Eng.), Associate Professor, Kazan National Research Technical University n.a. A.N. Tupolev – KAI E-mail: tchoni@rambler.ru

The peculiarities of the antenna's local phase center (LPhC) position calculating, caused both by some amount of uncertainty in the very concept of the LPhC, and by the need to eliminate phase surges due to inverse trigonometric functions computation have been discussed. The coordinates of the LPhC depend on the observation direction, with the change of which, in general, the LPhC draws the surface in three-dimensional space, or in the two-dimensional situation, the hodograph-line, often, of an intricate configuration. By the examples of the circle antenna array of elements having cardioid patterns, the calculation results for three varieties of algorithms have been compared. The article has a wealth of LPhC-hodographs as well. It demonstrates that calculating the LPhC as the center of the in-phase curve curvature can lead to erroneous results that contradict the physical sense.

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