Sandwiched Graphene Clad Laminate: A Binder‐Free Flexible Printed Circuit Board for 5G Antenna Application

Abstract

Printed circuit board (PCB), as the basic mechanically supports of electronic devices, is widely used in circuit, radio frequency (RF), and other fields. [1,2] Copper is the most commonly used conductive material in the PCB structure due to its high electrical conductivity and matured manufacture techniques. [3] Despite the advantages, with the increasing demand of electronic products, metal waste is becoming a severe problem, as it can cause significant environment pollutions. [4-6] Metal materials also suffer from high prices (because of their limited reserves), relatively poor flexibility, large density, and easily oxidized. As communication technologies developing, copper and other traditional metals-based PCB are becoming difficult to meet the new requirements for 5G communication devices, such as of being lightweight, flexible, miniaturized, and chemically stable under certain severe conditions. [7] Therefore, it is necessary to find a suitable material to realize metal substitution in the field of electronic products based on PCB. Many attempts have been made to find the right candidates for such substitution of copper so far. Recently, carbon-based allotropic materials, such as carbon nanotubes (CNTs), carbon fibers, graphene, and fullerenes, have been widely investigated in the fields of antennas, [8-10] sensors, [11,12] transistors, [13] and other electronic fields, [14,15] given that they are abundant in nature and their advanced properties of lightweight, corrosion resistant, and environmental friendly. For instance, CNTs not only have excellent mechanical properties, biocompatibility, and chemical stability, [16-18] but also have the disadvantages of low conductivity, complex film-forming process, and high contact resistance. [19-21] Fullerenes, such as the CNTs, also suffer from low conductivity and difficult film forming, [22] which lead to the problems of high loss and unsatisfactory performance

Anticorrosive Multi-band 5G Wireless Communication and THz Electromagnetic-Interference Shielding with Graphene Assembled Film

“…45). First, the GAF and the dielectric substrate (FR-4, Silica gel lm, Rogers 5880, PET) were combined by hot pressing to form GAF Printed Circuit Board (PCB) 29 . To adapt the laser engraving machine, the carving patch of the device dimensions output by the simulation software was calculated using LPKF CircuitPro PL 2.0.…”

“…However, the conducting graphene layer in these structures typically has limited thickness or low coductivity, which results in high surface resistance and poor device performance 22,23 . Recent breakthroughs in the reduction of graphene oxide 24 and exfoliation of pristine graphene 25 have demonstrated that graphene assembled structures can reach electrical conductivities of up to 10 5 S/m [26][27][28] , and that such techniques can be applied in WCE 29,30 . Such electrical conductivity, however, is still two orders of magnitude lower than that of metal-based materials.…”

Wideband and low sidelobe graphene antenna array for 5G applications

“…Recently, a flexible high conductivity graphene assembled film (GAF) was applied to antenna design reported in our previous works. The GAF antennas exhibited comparable gain, radiation patterns, and return loss to commercial copper antennas [11][12][13]. On this basis, we further investigate the development of GAF millimeter wave large antenna array.…”

Low profile and miniaturized dual‐band antenna based on graphene assembled film for wearable applications

“…30,31 Furthermore, the GAF has tremendous mechanical properties 32 and passed the 180 large-angle cyclic bending pressure test. 8,11,33 The results are shown in Table . 2. Compared with copper.…”