The purpose of this study is to prepare a resistive lossy material using conducting polymers for electromagnetic wave absorbers. This paper presents a conductive paste largely composed of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) with a polyurethane binder. The various secondary compounds are added in small amounts to an aqueous blended solution in order to enhance the electrical and mechanical properties of the conductive thin film. The synthesized conductive paste is characterized through electrical, chemical, and morphological analyses. The electrical conductivity of the thin film is measured using a four-point probe and surface profiler. The chemical and morphological changes are studied in various experiments using a Raman microscope, X-ray photoelectron spectroscopy, a scanning electron microscope, and an atomic force microscope. In order to verify the applicability of the synthesized conductive paste, which is composed of 70 wt% PEDOT:PSS, 30 wt% polyurethane, and secondary additives (DMAE 0.4 wt%, A-187 0.5 wt%, DMSO 7 wt%, Dynol 604 0.1 wt%, PUR 40 2.5 wt%), the Salisbury screen absorber is fabricated and evaluated in the X-band. According to the results, the absorber resonates at 9.7 GHz, the reflection loss is −38.6 dB, and the 90% absorption bandwidth is 3.4 GHz (8.2 to 11.6 GHz). Through this experiment, the applicability of the PEDOT:PSS-based conductive paste is sufficiently verified and it is found that excellent radar-absorbing performance can be realized.

This study proposes a rational optimum design procedure for broadband radar absorbers composed of a square-loop-shaped resistive frequency selective surface (FSS) that are placed on an E-glass fabric/epoxy laminate and grounded by Cu foil covering the X-band (8–12 GHz). A rational optimum design procedure for the broadband absorbing performance was presented based on the analytical and numerical illustration. The effects of the surface resistance of the FSS and dielectric substrate on the design process and performance of the absorber are examined. The resistive FSS was fabricated using screen-printing technology with carbon-type ink as a demonstration. The demonstration samples were developed considering the sectional profile of the circuit lines composing the printed FSS. It revealed that the experimental reflection loss encompassing the frequency range over the entire X-band was repeatable and similar to the simulation result.

This letter proposes a near-field beam focusing transmitarray-based (TA-based) free space measurement system that is extremely miniaturized rather than horn-to-horn and dielectric lens-based measurement systems for radio frequency (RF) metamaterial composites. Reducing the size of the measurement setup is limited due to the natural phenomenon of conventional systems. Contrastively, TA-based system could overcome the limitation because of its phase-shifting ability to maintain the planar appearance. A device-under-test (DUT) was measured without any distortion utilizing the beam focusing characteristic of the proposed TA, which produces a uniform wavefront phase without diffraction over the DUT aperture. The proposed TA could focus the EM wave within a distance of 2 cm from the horn antenna while maintaining the phase error under $14.5^\circ$ , resulting in a plane wave-like phase. Consequently, the RF metamaterial composites could be measured at a short focal distance of 21.7% of the distance required by the conventional free-space system without additional absorbers. Further, the frequency response of DUT (i.e., $|S_{21}|$ and $\angle S_{21}$ ) could be obtained adequately compared to the full-wave simulation. The difference of transmission zero frequency between simulation and measurement was less than 1.6%.

In this paper, millimeter-wave absorbers are proposed for the WiGig communication frequency band (55–68 GHz) and a part of the 5G FR2 frequency band (22–44 GHz). Both proposed absorbers are designed to exhibit absorption performances greater than -10 dB at normal incidence and -8 dB at 45° oblique incidence within the frequency bands of interest. The absorbers feature a laminated structure composed of metasurfaces and polymeric substrates. The metasurfaces are fabricated by printing a conventional square-loop periodic pattern on polyimide film with resistive carbon ink using a screen-printing technique. The square-loop pattern is designed by accounting for the effect of the circuit linewidth of the printed square-loop pattern on the effective sheet resistance of its constituent circuit line. The absorbers are fabricated by attaching the metasurface print onto a polymer substrate and using copper film as a ground to the bottom. The performance of the fabricated millimeter-wave absorbers was verified using free-space measurement equipment, with the results confirming the achievement of the required absorption performance under normal and oblique incidences.

This paper presents a broadband compact omnidirectional UHF antenna–radome package for airborne applications, where reliable communication, low observability, and electromagnetic compatibility are critical. Omnidirectional radiation is essential for maintaining consistent radio communication links regardless of aircraft attitude during flight. Conventional blade antennas achieve such coverage but suffer from increased aerodynamic drag, higher radar cross-section (RCS), and limited conformal integration capability. To address these limitations, a low-profile hybrid structure combining a patch radiator with a broadband monocone is proposed. An integrated metallic ground wall reduces sensitivity to installation surroundings, suppresses structural interference, and enhances RF (Radio Frequency) compatibility. The antenna achieves an electrical size of 0.555λ × 0.555λ × 0.072λ at 338 MHz. A lightweight sandwich-structured glass fiber-reinforced plastic (GFRP) radome is fabricated to ensure mechanical robustness and environmental protection while maintaining negligible RF loss. Measurements confirm a −10 dB bandwidth of 32.7%, stable omnidirectional radiation, and gain exceeding −0.2 dBi throughout the operating band with peak realized gain of 2.6 dBi within the investigated frequency range. The radome causes negligible gain degradation, with insertion loss below 0.4 dB. The proposed package provides a practical solution for airborne platforms requiring compact, broadband, and installation-resilient antenna systems.