This paper presents a study on artificial magnetic conductor (AMC) surfaces and their application to low-profile high-gain planar antennas. The research explores the use of AMC surfaces, which are formed by periodic metallic arrays on a grounded dielectric substrate, to achieve high-gain, low-profile antennas. The study uses a resonant cavity model and ray theory to analyze the behavior of AMC surfaces and their application in antenna design. The paper discusses the properties of AMC surfaces, which can be modeled as resonant cavities. These surfaces are used as ground planes in high-gain microstrip patch antennas with partially reflective superstrates. The use of AMC surfaces reduces the antenna profile to approximately a quarter wavelength, significantly improving the antenna's performance. The study validates the design using full-wave analysis and measurements, showing that the AMC surface can be used to achieve a high-gain, low-profile antenna. The research also investigates the bandwidth and center frequency of AMC surfaces, finding that the bandwidth is defined as the range from +90° to -90° on either side of the central frequency. The study shows that the use of AMC surfaces can lead to a significant reduction in antenna profile while maintaining high gain. The paper also discusses the effect of substrate thickness on the performance of AMC surfaces, showing that increasing the thickness can improve the bandwidth. The paper concludes that the use of AMC surfaces in antenna design provides a new approach to achieving high-gain, low-profile antennas. The study demonstrates that the resonant cavity model can be used to predict the performance of AMC surfaces and their application in antenna design. The results show that the use of AMC surfaces can lead to a significant improvement in antenna performance, with a reduction in profile and an increase in gain. The study also highlights the importance of using full-wave analysis and measurements to validate the design of AMC surfaces and their application in antenna design.This paper presents a study on artificial magnetic conductor (AMC) surfaces and their application to low-profile high-gain planar antennas. The research explores the use of AMC surfaces, which are formed by periodic metallic arrays on a grounded dielectric substrate, to achieve high-gain, low-profile antennas. The study uses a resonant cavity model and ray theory to analyze the behavior of AMC surfaces and their application in antenna design. The paper discusses the properties of AMC surfaces, which can be modeled as resonant cavities. These surfaces are used as ground planes in high-gain microstrip patch antennas with partially reflective superstrates. The use of AMC surfaces reduces the antenna profile to approximately a quarter wavelength, significantly improving the antenna's performance. The study validates the design using full-wave analysis and measurements, showing that the AMC surface can be used to achieve a high-gain, low-profile antenna. The research also investigates the bandwidth and center frequency of AMC surfaces, finding that the bandwidth is defined as the range from +90° to -90° on either side of the central frequency. The study shows that the use of AMC surfaces can lead to a significant reduction in antenna profile while maintaining high gain. The paper also discusses the effect of substrate thickness on the performance of AMC surfaces, showing that increasing the thickness can improve the bandwidth. The paper concludes that the use of AMC surfaces in antenna design provides a new approach to achieving high-gain, low-profile antennas. The study demonstrates that the resonant cavity model can be used to predict the performance of AMC surfaces and their application in antenna design. The results show that the use of AMC surfaces can lead to a significant improvement in antenna performance, with a reduction in profile and an increase in gain. The study also highlights the importance of using full-wave analysis and measurements to validate the design of AMC surfaces and their application in antenna design.