TY - JOUR

T1 - Upper Bounds and Design Guidelines for Realizing Uncorrelated Ports on Multimode Antennas Based on Symmetry Analysis of Characteristic Modes

AU - Peitzmeier, Nikolai

AU - Manteuffel, Dirk Michael

N1 - Funding Information: Manuscript received June 1, 2018; revised February 8, 2019; accepted February 23, 2019. Date of publication March 18, 2019; date of current version May 31, 2019. This work was supported by Deutsche Forschungs-gemeinschaft (DFG) within the Priority Program SPP 1655 under Grant MA 4981/4-2. (Corresponding author: Nikolai Peitzmeier.) The authors are with the Institute of Microwave and Wireless Systems, Leibniz University Hannover, 30167 Hannover, Germany (e-mail: peitzmeier@hft.uni-hannover.de; manteuffel@hft.uni-hannover.de).

PY - 2019/6

Y1 - 2019/6

N2 - The design of multiport antennas for multiple-input multiple-output (MIMO) applications utilizing characteristic modes is investigated. For good MIMO performance, uncorrelated antenna ports are generally required. In order to analyze the port correlation, symmetry analysis based on group theory and matrix representations is applied to the theory of characteristic modes. The characteristic surface current densities act as basis functions of the irreducible representations of the symmetry group of the antenna. Current densities belonging to different representations or belonging to different rows of the same representation are orthogonal to each other and can, thus, be excited separately. Therefore, an upper bound for the number of uncorrelated antenna ports can be derived for a given antenna structure based on the symmetry analysis of the characteristic modes. Furthermore, design guidelines on which antenna geometry to choose in order to realize a given number of uncorrelated antenna ports and on how to implement these ports can be deduced. The concept is illustrated by means of examples.

AB - The design of multiport antennas for multiple-input multiple-output (MIMO) applications utilizing characteristic modes is investigated. For good MIMO performance, uncorrelated antenna ports are generally required. In order to analyze the port correlation, symmetry analysis based on group theory and matrix representations is applied to the theory of characteristic modes. The characteristic surface current densities act as basis functions of the irreducible representations of the symmetry group of the antenna. Current densities belonging to different representations or belonging to different rows of the same representation are orthogonal to each other and can, thus, be excited separately. Therefore, an upper bound for the number of uncorrelated antenna ports can be derived for a given antenna structure based on the symmetry analysis of the characteristic modes. Furthermore, design guidelines on which antenna geometry to choose in order to realize a given number of uncorrelated antenna ports and on how to implement these ports can be deduced. The concept is illustrated by means of examples.

KW - Antenna theory

KW - characteristic modes

KW - group theory

KW - multimode antenna

KW - multiple-input multiple-output (MIMO)

KW - symmetry

UR - http://www.scopus.com/inward/record.url?scp=85067008129&partnerID=8YFLogxK

U2 - 10.1109/tap.2019.2905718

DO - 10.1109/tap.2019.2905718

M3 - Article

AN - SCOPUS:85067008129

VL - 67

SP - 3902

EP - 3914

JO - IEEE Transactions on Antennas and Propagation

JF - IEEE Transactions on Antennas and Propagation

SN - 0018-926X

IS - 6

M1 - 8668520

ER -