Summary
International Symposium on Antennas and Propagation
2008
Session Number:3C21
Session:
Number:3C21-1
Electric Field Measurement Using Multiple-Loaded Linear Scatterers
M.A. Abou-Khousa, R. Zoughi,
pp.-
Publication Date:2008/10/27
Online ISSN:2188-5079
Summary:
Modulated scatterer techniques (MST) based on 1D and 2D arrays of small loaded linear scatterers have been used extensively for rapid electric field distribution measurements at microwave frequencies [1]. In most applications, a compact array of closely-spaced small loaded dipoles is used in order to construct a representative map of the electric field of interest. The performance of the MST-based electric field measurement system depends on many factors. As stated in [2], "Six basic factors that can have an impact on measurement system performances are as follows: 1) dynamic range, 2) interelement mutual coupling, 3) interaction between the MST array and test antenna, 4) parasitic signals (modulated and/or unmodulated), 5) dispersion of element scattering characteristics, and 6) probe correction." These factors impose many tradeoff considerations that need to be resolved on perapplication basis. For instance, the interelement mutual coupling combined with the fact that the utilized elements are commonly small scatterers (i.e., short dipoles) can adversely impact the system sensitivity, and hence reduce the overall system dynamic range. On the other hand, using stronger (loaded) scatterers can enhance the sensitivity when effective probe correction and compensation techniques are employed. Such a tradeoff was investigated in [3] where it was articulated that "For practical reasons, instead of trying to build noninterfering (and therefore more complicated and perhaps less sensitive) sensors, one can use common sensors (simpler, inexpensive, and possibly more sensitive) and include them in the reconstruction formulism itself." In line with this concept, we propose a new method for electric field distribution measurement based on utilizing multiple loaded linear scatterers (MLS) instead of the conventional arrays of discrete elements. It will be shown that, by utilizing a linear scatterer loaded at multiple discrete locations over its length, the electric field of interest can be reconstructed accurately from scattered field measurements taken under distinct modulation states. The feasibility of the proposed method for electric field distribution measurement is demonstrated via numerical simulations.