Publications by authors named "Haoran Zu"

Traditional metal materials used in electronic devices are often problematic due to issues like bending resistance, oxidation leading to failure, and environmental pollution. To address these challenges, microwave electronic devices are constantly casting around for metal substitute materials with additional characteristics such as flexibility, anticorrosive, and eco-friendly. However, finding suitable materials that are accessible for radiofrequency (RF) applications is a difficult yet promising task.

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Millimeter-wave and short-range wireless communication is an important part of the Internet of Things due to its advantages of high transmission speed and large data capacity. In this paper, two antenna arrays operating at typical millimeter-wave bands (45 and 60 GHz) based on graphene-assembled films (GAF) are proposed for short-range wireless communication application. The 45 GHz graphene-assembled film antenna array is in the form of a magnetoelectric dipole antenna with a strip slot coupling to achieve bidirectional radiation, which offers an operating bandwidth of 40-49.

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In this work, a dual-band transmissive polarization conversion metasurface (PCM), with omnidirectional polarization and low profile, is proposed. The periodic unit of the PCM is composed of three metal layers separated by two substrates. The upper patch layer of the metasurface is the patch-receiving antenna, while the bottom layer is the patch-transmitting antenna.

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A quad-band metamaterial absorber using a periodically arranged surface structure placed on an ultra-thin substrate is demonstrated in this paper. Its surface structure consists of a rectangular patch and four L-shaped structures distributed symmetrically. The surface structure is able to have strong electromagnetic interactions with incident microwaves, thereby generating four absorption peaks at different frequencies.

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Metamaterial absorbers (MMAs) that absorb electromagnetic waves among an ultra-broad frequency band have attracted great attention in military and civilian applications. In this paper, an ultra-broadband and highly-efficient MMA is presented. The unit cell of the proposed MMA was constructed with two cross-placed stand-up gradient impedance graphene films, which play a key role in improving impedance matching.

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This paper presents a low-profile ultrawideband antenna for on-body wearable applications. The proposed antenna is based on highly conductive flexible graphite films (FGF) and polyimide (PI) substrate, which exhibits good benefits such as flexibility, light weight and corrosion resistance compared with traditional materials. By introducing flaring ground and an arrow-shaped slot, better impedance matching is achieved.

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