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Abstract: A circularly polarized (CP) antenna integrated with an artificial magnetic conductor (AMC) plane is presented. The AMC plane is aimed at enhancing the gain of the CP antenna, besides reduced back‐radiation, and avoiding radiation toward other high‐frequency components on the CubeSat. It consists of a 3 × 3 array of diamond‐shaped unit cells placed behind the complementary dipole‐based antenna. To enable deployability and compact deployment size, the AMC structure is designed on a thin flexible Kapton film as substrate, whereas its metallic components are formed using Nickel conductive paint. Meanwhile, the CP antenna is designed on a thin Rogers RO4003C substrate and located on top of the AMC plane at a 20 mm distance. The combined structure operates at 2.4 GHz with satisfactory reflection and radiation performance. It is sized at 99 mm × 99 mm × 21.485 mm3, with 450 MHz (18%) of 10 dB impedance bandwidth and 250 MHz (10%) of 3 dB axial ratio bandwidth. The AMC plane also improved its gain from 3.05 dBi up to 5.35 dBi. [ABSTRACT FROM AUTHOR]

Wireless systems manufacturers desire a low-profile, wideband, circularly polarized (CP) antenna. Generally, a single-feed CP microstrip antenna (CPMA) has a simple configuration but is hindered by a narrow, 3-dB axial ratio (AR) bandwidth. The bandwidth of a multiple-feed CPMA can be enhanced but requires a complicated and larger feeding network. Many techniques have been employed to improve AR bandwidth, such as using dual-feed, network-based structures [1], stacked patches [2]?[3], array antennas with sequential feeding network [4], and multilayered structures [5]. However, these CP antennas are based on multiradiating patches or complicated feeding structures. [ABSTRACT FROM AUTHOR]

A novel design for wideband circularly polarized antenna is presented. The proposed antenna is a coplanar waveguide structure. The slot in the ground plane is rectangular and placed asymmetric. The circular polarization is achieved by using a modified L-shape radiating patch and by adding inverted L-shaped strip at one corner. Axial ratio bandwidth (ARBW) of the antenna is greatly enhanced by connecting one end of the L-shaped patch to the ground via a slit and cutting additional slots in the ground plane. The measured impedance bandwidth and 3 dB ARBW is 3.4 GHz (2.2–5.6 GHz) and 1.97 GHz (2.2–4.17 GHz), respectively, which can cover WLAN (2.4 GHz band), RFID reader (2.45 GHz band), WiMAX (3.2–3.7 GHz band) other wireless communication applications. The average measured boresight gain is 3–4 dBi. The time domain analysis of the antenna is also performed. The measured group delay is nearly constant in the operating band. The system fidelity factor of the antenna is also measured for different azimuth angles. [ABSTRACT FROM AUTHOR]

Novel circular polarized sensors and antennas for biomedical systems, energy harvesting, Internet of Things (IoT), and 5G devices are presented in this article. The major challenge in development of healthcare, IoT, 5G and communication systems is the evaluation of circular polarized active and passive wearable antennas. Moreover, a low-cost wearable sensor may be evaluated by printing the microstrip antenna with the sensor feed network and the active devices on the same substrate. Design considerations, comparison between simulation and measured results of compact circular polarized efficient sensors for wireless, 5G, energy harvesting, IoT, and medical systems are highlighted in this article. The electrical performance of the novel sensors and antennas on and near the user body were evaluated by employing electromagnetic software. Efficient passive and active metamaterial circular polarized antennas and sensors were developed to improve the system electrical performance. The wearable compact circular polarized passive and active sensors are efficient, flexible, and low-cost. The frequency range of the resonators, without Circular Split-Ring Resonators CSRRs, is higher by 4% to 10% than the resonators with CSRRs. The gain of the circular polarized antennas without CSRRs is lower by 2 dB to 3 dB than the resonators with CSRRs. The gain of the new passive antennas with CSRRs is around 7 dBi to 8.4 dBi. The bandwidth of the new circular polarized antennas with CSRRs is around 10% to 20%. The sensors VSWR is better than 3:1. The passive and active efficient metamaterials antennas improve the system performance. [ABSTRACT FROM AUTHOR]

A circularly-polarized conical-beam microstrip patch antenna, with a coplanar conductor pattern, is realized as an array of a number of stripline-fed slotted patches whose diagonal corners are cut off and whose feedlines meet at a central point. Prototypes of such an antenna array with four patches are studied and tested. The results show reasonable agreement between measured and theoretical results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 78–81, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23956 [ABSTRACT FROM AUTHOR]