RF Signal Multiplexer Embedded Into Multifunctional Composite Structure

Low-Cost Direct-Writing of Silver-Based Ink for Planar Microwave Circuits up to 10 GHz

“…Although effective conductivity decreases with increasing frequency, using an average value of 2×10 6 S/m yields consistent results with RF simulations above 500 MHz. A similar decrease in RF effective conductivity has been reported in the literature for this type of ink [37], [38]. Fig.…”

“…We designed two basic types of circuits widely used for this purpose: a long microstrip line, commonly used to determine substrate losses, and a Tresonator, which is used to accurately determine the substrate dielectric constant [45]. On the other hand, SC-ink conductivity at microwave frequencies, 𝜎 , is an unknown and is expected to be lower than its DC value, 𝜎 , due to, among other reasons, surface roughness and width irregularities [38]. To estimate tan 𝛿 and 𝜎 , two 50-Ω microstrip lines of 10 cm length (2.90 mm nominal width) were fabricated: one copper-based by standard etching technique and the other by direct SC-ink writing.…”

“…It is known that the effective conductivity can vary as a function of operating frequency. In this regard, there are several works on the performance of conductive inks used in direct-writing for RF applications up to 4 GHz [37], and 6 GHz [38]. This could explain why the RF applications in which conductive ink direct-write dispensing has been used do not go beyond 4.5 GHz [8], [24].…”

A Route to Sustainable Aviation: A Roadmap for the Realization of Aircraft Components With Electrical and Structural Multifunctionality

“…Copper foil does not physically bond well to the resin matrix, resulting in areas of structural weakness. In [46], a carbon nickel copper veil was shown to have much better porosity and better adhesion. However, whilst the electrical conductivity was high, this was used for a very low power, high frequency application.…”

“…Very low power, high frequency electronic switches have been successfully integrated into CFRP structures, where metallic materials have been used to form the electrical components. In [46] it is reported that a radio frequency (RF) switch has been integrated into a ten-ply structure, with electrical circuitry placed on the central ply using a carbonnickel-copper (C-Ni-Cu) veil, along with the electronic chips containing the semi-conductor switch. Polyimide is reported as a substrate for an array of very low power (~100 µW) diodes, which are electrically connected using silver and gold conductors in [83].…”