In this paper, a compact, flexible Vivaldi antenna is designed, and an array of nine identical antennas of this type is used as a microwave breast imaging model to detect cancerous tumors in the multilayers phantom model presented in this paper. The nine-antenna array is used to measure the backscattering signal of the breast phantom, where one antenna acts as a transmitter and the other eight antennas act as receivers of the scattered signals. Then, the second antenna is used as a transmitter and the other antennas as receivers, and so on till we have gone through all the antennas. These collected backscattered signals are used to reconstruct the image of the breast phantom using software called “Microwave Radar-based Imaging Toolbox (MERIT)”. From the reconstructed image, the tumor inside the breast model can be identified and located. Different tumor sizes in different locations are tested, and it is found that the locations can be determined irrespective of the tumor size. The proposed modified Vivaldi antenna has a very compact size of 25 × 20 × 0.1 mm³ and has a different geometry compared with conventional Vivaldi antennas. The first version of the antenna has two resonant frequencies at 4 and 9.4 GHz, and because we are interested more in the first band, where it gives us sufficient resolution, we have notched the second frequency by etching two slots in the ground plane of the antenna and adding two rectangular parasitic elements on the radiating side of the antenna. This technique is utilized to block the second frequency at 9.4 GHz, and, as a result, the bandwidth of the first resonant frequency is enhanced by 20% compared with the first design bandwidth. The modified antenna is fabricated on Polyimide flexible material 0.1 mm thick with a dielectric constant of 3.5 using a standard PCB manufacturing process. The measured performance of this antenna is compared with the simulated results using the commercially available simulation software Ansoft HFSS, and it is found that the measured results and the simulated results are in good agreement.

The concept of nanosatellite technology becomes a viable platform for earth and space observation research to minimize cost and build time for the payload. The communication approach is the essential fundamental attribute of a satellite, of which the antenna is a crucial component for forming a communication link between the nanosatellite and the earth. The nanosatellite antenna must comply with some special requirements like compact size, lightweight, and high gain with a space-compatible structure. This paper proposes a compact metamaterial-based Ku-band antenna with circular polarization for the nanosatellite communication system. The designed antenna obtained an impedance bandwidth of 2.275 GHz with a realized gain of 6.74 dBi and 3 dB axial beamwidth of 165° at 12.10 GHz. The overall antenna size of the designed is 0.51λ × 0.51λ × 0.17λ, which is fabricated on Rogers 5880 substrate material. The antenna results performance has been examined with a 1 U nanosatellite structure and found suitable to integrate with metallic and nonmetallic surfaces of any miniature nanosatellite structure.

The concept of the nanosatellite comes into play in launching miniaturized versions of satellites or regarding payloads with minimizing cost and building time. The economic affordability of nanosatellites has been promoted with a view to launching various nanosatellite missions. The communication system is one of the most important aspects of a satellite. The antenna is a key element for establishing a communication link between the earth and the nanosatellite. The antenna and solar panel of the nanosatellite are two of the most vital components that profoundly impact antenna type and design. This paper proposes a non-deployable lower ultra-high frequency (UHF) antenna, strategically mounted on the satellite body, to address the constraints of deployment complexity and solar panel integration. The antenna was fabricated and performances measured with a 1U nanosatellite structure, which achieved resonance frequency at 401 MHz frequency bands with 0.672 dBi realized gain. The overall antenna size is 0.13λ × 0.13λ × 0.006λ. The major challenges addressed by the proposed antenna are to design a nanosatellite-compatible lower UHF antenna and to ensure solar irradiance into the solar panel to minimize input power scarcity.

This work deals with the design and development of a conformal series-fed antenna structure operating at the 60 GHz frequency. The proposed antenna operates from 57 GHz to 62 GHz with good return loss and radiation characteristics for 6G and beyond applications. The antenna is shown to give a good gain of more than 14.7 dBi with directional radiation beam in the hemispherical boresight direction. The fabricated prototype is verified with the simulated result, and it is found to be a good matching. The step-by-step antenna design process, parametric variation, and a detailed study are also reported. For a case study, this series-fed antenna conformal configuration is also embedded on a cylindrical structure. From this study, similar resonant and radiation performance characteristics are observed. Since the structure is compact, conformal, and gives better performance, it can be suitable for applications such as 6G, radar, guided missiles, body-centric medical imaging, etc.