Forward Scattering of Loaded and Unloaded Antennas

• Published in: IEEE transactions on antennas and propagation Vol. 60; no. 12; pp. 5663 - 5668
• Main Authors: Gustafsson, M., Andersen, J. B., Kristensson, G., Pedersen, G. F.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.12.2012; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Absorption; Absorption efficiency; Antenna measurements; Antennas; Applied sciences; Cross sections; Dipole antennas; Electrical Engineering, Electronic Engineering, Information Engineering; Elektroteknik och elektronik; Engineering and Technology; Exact sciences and technology; Extinction; extinction cross section; Forward scattering; Integrals; Loaded antennas; Lossless; polarizability; Radiocommunications; Receiving antennas; Scattering; Sum rule; Sum rules; Teknik; Telecommunications; Telecommunications and information theory; Performance evaluation; Open circuit; Lossless circuit; Polarizability; Cross-over phenomenon; Cylindrical antenna; sum rule; Dipole antenna; Absorption efficiency; Short circuit; Forward scattering; scattering; Weight function; Radiation pattern
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2012.2214191

Forward scattering of antennas is related to antenna performance via the forward-scattering sum rule. The forward-scattering sum rule is an integral identity that shows that a weighted integral of the extinction cross section over all spectrum is proportional to the static polarizability of the antenna structure. Here, the forward-scattering sum rule is experimentally verified for loaded, short-circuit, and open-circuit cylindrical dipole antennas. It is also shown that the absorption efficiency cannot be greater than 1/2 for reciprocal linearly polarized lossless matched antennas with a symmetric radiation pattern in the forward and backward directions.