On the Constant Input Impedance of the Archimedean Spiral Antenna in Free-Space

• Published in: IEEE transactions on antennas and propagation Vol. 62; no. 7; pp. 3869 - 3872
• Main Authors: Teng-Kai Chen, Huff, Gregory H.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.07.2014; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna measurements; Antennas; Applied sciences; Archimedean spiral antennas; Constants; Electric fields; Exact sciences and technology; Impedance; Input impedance; Mathematical analysis; Radiocommunications; Slot lines; Spiral antennas; Spirals; Telecommunications; Telecommunications and information theory; Helical antenna; Input impedance; Electric field; Field distribution; Free space propagation; Spiral structure; Wireless telecommunication; Analytical method; Printed antenna; Plane antenna; Archimedean spiral antennas
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2014.2320760

This communication examines the relationship of metal width and arm spacing of a planar printed spiral antenna on its constant input impedance. Observations on the current and electric field distribution are made first to establish the physical mechanisms responsible for the impedance behavior. An analytical model is proposed to analyze the excited mode on the spiral antenna, which can be used to analytically obtain the constant input impedance in the spiral's radiation region. The expression in this work can be applied to evaluate the input impedance for a variety of non-self-complementary spiral structures.