Corrections to “Bandwidth Limitations on Linearly Polarized Microstrip Antennas” [Feb 10 250-257

When circularly polarized (CP) microstrip antennas are bent, the polarization becomes elliptical. We present a simple model that describes the phenomenon. The two linear modes present in a CP patch are modeled separately and added together to produce CP. Bending distorts the almost-spherical equiphase surface of a linearly polarized patch, which leads to phase imbalance in the far-field of a CP patch. The model predicts both the frequency shifting of the axial ratio band as well as the narrowing of the axial ratio beam. Uncontrolled bending is a problem associated especially with flexible textile antennas, and wearable antennas should therefore be designed somewhat conformal.

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Analysis and Design of Probe-Fed Linearly-Polarized Microstrip Antennas on FR4 Substrates

IEEE Latin America Transactions ◽

10.1109/tla.2014.6893987 ◽

2014 ◽

Vol 12 (6) ◽

pp. 965-970 ◽

Cited By ~ 2

Author(s):

Daniel Chagas Nascimento ◽

Jose Carlos Silva Lacava

Keyword(s):

Microstrip Antennas ◽

Analysis And Design ◽

Linearly Polarized

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Probe-Fed linearly-polarized electrically-equivalent microstrip antennas on FR4 substrates

Journal of Microwaves Optoelectronics and Electromagnetic Applications ◽

10.1590/s2179-10742014000100005 ◽

2014 ◽

Vol 13 (1) ◽

pp. 55-66 ◽

Cited By ~ 3

Author(s):

D. C. Nascimento ◽

J. C. da S. Lacava

Keyword(s):

Microstrip Antennas ◽

Linearly Polarized

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Analysis and Design of Cavity-Backed Probe-Fed Hybrid Microstrip Antennas on FR4 Substrate

International Journal of Antennas and Propagation ◽

10.1155/2015/206967 ◽

2015 ◽

Vol 2015 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

D. C. Nascimento ◽

Prêntice C. Ribeiro Filho ◽

Alexis F. Tinoco-S ◽

J. C. da S. Lacava

Keyword(s):

Microstrip Antenna ◽

Mutual Coupling ◽

Low Cost ◽

Microstrip Antennas ◽

Substrate Integrated Waveguide ◽

Cross Polarization ◽

Analysis And Design ◽

Linearly Polarized

A novel cavity-backed probe-fed linearly polarized microstrip antenna based on the concept of hybrid radiators is proposed and implemented. The resulting flush-mounted antenna exhibits symmetrical bandwidth, low cross-polarization radiation in theH-plane, due to its hybrid patch, and low cost, since it can be built on a FR4 laminate. Substrate integrated waveguide technology is used in the fabrication of the metallic cavity. The effect of mutual coupling is analyzed for two classical arrangements: the side-by-side and the collinear configurations.

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A Broadband Impedance-Matching Method for Microstrip Patch Antennas Based on the Bode-Fano Theory

Frequenz ◽

10.1515/freq-2018-0037 ◽

2018 ◽

Vol 72 (7-8) ◽

pp. 373-380

Author(s):

Christopher M. A. Bonenberger ◽

Klaus W. Kark

Keyword(s):

Input Impedance ◽

Low Cost ◽

Impedance Matching ◽

Single Mode ◽

Wide Band ◽

Low Complexity ◽

Microstrip Antennas ◽

Patch Antennas ◽

Linearly Polarized ◽

Matching Techniques

Abstract Considering the narrow bandwidth of microstrip antennas, but also their applicability in upcoming technologies, this paper addresses the problem of wide-band matching, the theoretical bounds on the matching bandwidth and low-cost and low-complexity matching strategies. In this context the Bode-Fano bounds of single mode, linearly polarized aperture-coupled microstrip antennas is evaluated, optimized and compared to the theoretical bounds on matching bandwidth of other common feeding technologies. A detailed study of the input impedance of aperture-coupled patch antennas shows how to widen the Fano bounds. Based on this, a straight-forward and effective method to optimize the Fano bound is given. After optimization of the antennas input impedance, basic matching techniques can be applied, to exploit the enlarged bandwidth potential. As an example a $\lambda/4$-transformer as matching element is proposed. Design equations and simulation and measurement results of X-band prototypes are given as verification.

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