Systematic CMA of the U-slot Patch with FEKO


  • John J. Borchardt Sandia National Laboratories Albuquerque, NM, USA


characteristic mode analysis, coupled mode theory, FEKO, U-slot patch antenna


Since its introduction 25 years ago, the probe-fed Uslot patch antenna has remained popular. Recently, Characteristic Mode Analysis (CMA) revealed these devices are governed by Coupled Mode Theory (CMT). Although this principle is conceptually simple, achieving this understanding is only possible through a systematic analysis using CMA. This paper uses the Uslot patch to illustrate a general process for analyzing electrically small antennas using CMA with the software package FEKO.


T. Huynh and K. F. Lee, "Single-layer single-patch wideband microstrip antenna," in Electronics Letters, vol. 31, no. 16, pp. 1310-1312, 3 Aug. 1995.

J. J. Borchardt and T. C. Lapointe, "U-Slot Patch Antenna Principle and Design Methodology Using Characteristic Mode Analysis and Coupled Mode Theory," in IEEE Access, vol. 7, pp. 109375-109385, 2019.

Altair Engineering, Inc. FEKO [Online] Available: https://altairhyperworks. com/product/FEKO

R. Harrington and J. Mautz, "Theory of characteristic modes for conducting bodies," in IEEE Transactions on Antennas and Propagation, vol. 19, no. 5, pp. 622-628, Sep. 1971.

J. Hong, "Couplings of asynchronously tuned coupled microwave resonators," in IEE Proceedings - Microwaves, Antennas and Propagation, vol. 147, no. 5, pp. 354-358, Oct. 2000




How to Cite

John J. Borchardt. (2020). Systematic CMA of the U-slot Patch with FEKO. The Applied Computational Electromagnetics Society Journal (ACES), 35(11), 1352–1353. Retrieved from