Quality Factor Comparison of Coaxial-Fed and Edge-Fed Electrically Small Microstrip Antennas

This letter presents and discusses the simulated and measured values of Q for microstrip antennas with different feeding schemes (edge-fed versus coaxial-fed) for regular (rectangular) and electrically small (meandered) designs. The edge-fed antennas are not matched, while the coaxial-fed are matched to 50Ω. The measured Q is compared to that given by exact and approximate formulas, simulations, and the Chu lower bound. The objective is to assess by how much a measurement of Q typically differs from its anticipated value, in regular and miniaturized microstrip antennas for different feeding schemes.

[1]  Ramesh Garg,et al.  Rectangular ring and H-shaped microstrip antennas—alternatives to rectangular patch antenna , 1985 .

[2]  J. Mclean.  A re-examination of the fundamental limits on the radiation Q of electrically small antennas , 1996 .

[3]  S.R. Best,et al.  Low Q electrically small linear and elliptical polarized spherical dipole antennas , 2005, IEEE Transactions on Antennas and Propagation.

[4]  S.R. Best.  A discussion on the quality factor of impedance matched electrically small wire antennas , 2005, IEEE Transactions on Antennas and Propagation.

[5]  S. R. Best.  State-of-the-art in the design of electrically small antennas , 2011, Proceedings of the 5th European Conference on Antennas and Propagation (EUCAP).

[6]  S. Best,et al.  Impedance, bandwidth, and Q of antennas , 2005 .

[7]  David M. Pozar,et al.  New results for minimum Q, maximum gain, and polarization properties of electrically small arbitrary antennas , 2009, 2009 3rd European Conference on Antennas and Propagation.

[8]  M. Gustafsson,et al.  Physical limitations on antennas of arbitrary shape , 2007, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[9]  Wolfgang J. R. Hoefer,et al.  Equivalent Series Inductivity of a Narrow Transverse Slit in Microstrip , 1977 .

[10]  H.A. Wheeler,et al.  Fundamental Limitations of Small Antennas , 1947, Proceedings of the IRE.

[11]  R. Hansen,et al.  Fundamental limitations in antennas , 1981, Proceedings of the IEEE.

[12]  김기채.  Small Antennas , 1992, Antenna and EM Modeling with MATLAB® Antenna Toolbox.

[13]  D. E. Anagnostou,et al.  Evaluation of the Quality Factor, Q, of Electrically Small Microstrip-Patch Antennas [Wireless Corner] , 2011, IEEE Antennas and Propagation Magazine.

[14]  G. A. E. Vandenbosch.  Explicit Relation Between Volume and Lower Bound for Q for Small Dipole Topologies , 2012, IEEE Transactions on Antennas and Propagation.

[15]  S..  A Re-Examination of the Fundamental Limits on the Radiation Q of Electrically Small Antennas , 2008 .

[16]  L. J. Chu.  Physical Limitations of Omni‐Directional Antennas , 1948 .