Shielding of instruments and humans from electromagnetic interference (EMI) has become increasingly important during the last decades due to more and more machines and devices radiating electromagnetic waves. While several applications can use rigid shields, more flexibility is enabled by developing bendable, drapable, ideally even stretchable EMI shielding. Textile fabrics can have these properties, combined with potentially good mechanical properties, depending on the textile structure and the chosen material. On the other hand, the necessary physical properties, especially conductivity and magnetic properties, cannot be taken for granted in normal textile fabrics. These properties have to be added by conductive yarn or layer coatings, integration of conductive or magnetic fibers, producing intrinsically conductive or magnetic fibers, etc. The article gives a critical comparison of the properties of materials typically used for this purpose, such as intrinsically conductive polymers, metal-coated fabrics and metal wires, MXene coatings, MXene fibers, carbon coatings, and fibers. The review concentrates on thematically suitable papers found in the Web of Science and Google Scholar from the last five years and shows that especially MXenes are highly investigated recently due to their high conductivity and EMI shielding effectiveness, while other conductive and magnetic coatings and fibers are nevertheless still interesting for the preparation of EMI shielding textile fabrics.

This letter discusses the design of a dual-polarized four-element linear antenna array with increased port-to-port isolation, intended for base stations of single-channel full-duplex systems. The antenna is designed for the U-NII 5.15—5.925 GHz frequency band and is characterized by port-to-port isolation higher than 57 dB and cross-polarization better than -27 dB within the main lobe. An electromagnetically-coupled microstrip antenna was used as a single element of the antenna array. Enhanced isolation was obtained owing to the multi-layer antenna structure and special feeding network utilizing the pairwise anti-phased feeding technique combined with a careful selection of phase-shifters and power dividers. The antenna parameters were optimized with the use of full-wave simulations, while the scattering parameters and radiation characteristics were verified by measurements.

In this paper, a modified triple-tuned microstrip bandpass filter is presented. The filter consists of inductively cross-coupled resonators tuned with varactors. The application of the additional source-load couplings together with resonator branch swapping results in two transmission zeros tuned concurrently with operating frequency. These transmission zeros placed on both sides of the passband significantly increase slope steepness in transition bands. The example filter tuned from 0.36 to 0.78 GHz and controlled by a single voltage was manufactured and validated by measurements. It has a constant fractional bandwidth of 11%, low in-band insertion loss ranging from 1.8 to 2.5 dB, and out-of-band attenuation up to 5 GHz without parasitic passbands. The obtained filter parameters made it useful for preselector networks.

This article presents a novel compact widely tunable bandpass filter. The filter consists of two resonators that are double-coupled, inductively, where the coupling inductances are elements of the input and output networks. The application of double-coupling enabled the transmission zero next to the upper cutoff frequency. This makes the filter useful for applications in preselector networks used in receiving systems with a low to intermediate frequency with the desired channel frequency lower than the image channel frequency. The article shows the practical realisation of the varactor-tuned example filter fabricated as a microstrip planar network of an overall size of 0.03${\lambda }_g$ × 0.045${\lambda }_g$. The tuning range of the proposed filter is from 410 MHz to 880 MHz with the fractional bandwidth equal to 7.5–8.1% and an in-band insertion loss better than −3.4 dB. The achieved IP3 value exceeds 17.5 dBm.

In this paper, an electrically small tunable microstrip bandpass filter with two concurrently tuned transmission zeros (TZs) is presented. The filter consists of two coupled resonators and varactors as tuning elements. An application of a multipath coupling network results in TZs on both sides of the passband. The filter controlled by a single voltage has a wide tuning range from 370 MHz to 800 MHz and a low insertion loss ranging from 1.9 dB to 3.4 dB. To achieve high attenuation in the stopband, two sections of the designed filter were cascaded. Both one-section and two-section filters were validated by measurements. The obtained results are in a very good agreement with simulations.

A hybrid method is proposed for specific absorption rate analysis in a human body located in the near field of typical GSM base-station panel antenna. The method combines FDTD technique with analytical description of the near field of isolated antenna. The approximate results are found to be in excellent agreement with the results obtained by using the traditional FDTD. The most important advantage of proposed approach is minimization of computer memory requirements and