A novel type of a broadband flexible electromagnetic absorbing panel made of a resistive pattern printed on a dielectric spacer backed by a conducting surface is investigated in this paper. It is shown that an appropriate choice of the shape and sheet resistance of the pattern allows extending an absorption spectrum up to an octave and beyond, which is very competitive over alternative solutions. The pattern is made of ink with graphene nano-platelets, which allows achieving expected sheet resistance with decent repeatability, what is confirmed with measurements undertaken with the DC point probe and microwave dielectric resonator techniques. An exemplary sample of the proposed absorber is manufactured and characterized, indicating a very good agreement between theoretical study and experiments.

This paper concerns the study of the mm-wave reconfigurable antennas based on S-PIN diodes suitable for using in mm-wave communication systems. The investigated antennas were designed, fabricated, and subjected to the measurements in both steady and transient states. One selected antenna was incorporated into a wireless system to determine its suitability for operating in such a system as a time-modulated linear array. By means of appropriate switching of the antenna, multiple radio frequency (RF) chains were simulated in a receiver having only one RF chain. This allowed applying a combining technique for improving the system performance in a presence of a strong interfering signal.

The results of shielding effectiveness (SE) measurements of textile materials containing metal by the free-space transmission technique (FSTT) in the 1-26.5 GHz frequency range are presented in the paper. It is shown that experimental data processing using time-domain gating (TDG) makes it possible to effectively remove diffracted and reflected components from the desired signal. The comparison with the results obtained by other techniques, namely modified FSTT with TDG and coaxial line probe technique (ASTM D4935-99) is given. The comparison shows that the proposed technique gives more reasonable results while the measurement set-up is simpler in realization.

This paper presents results of investigation on the radiation pattern generated with two-element Time Modulated Linear Array with single SP4T microwave switch. Utilization of SP4T switch instead of multiple SPST switches reduced an amount of power dissipated in matched loads and increased total efficiency. Due to the pulse-delay approach the null of radiation pattern has been continuously steered in a wide range of angles.

This letter presents a time-modulated antenna array (TMAA) with a dual-circular (left-hand and right-hand) polarization. The TMAA is composed of a single-pole four-throw (SP4T) radio-frequency (RF) switch and four linearly polarized elements arranged accordingly to the sequential rotation technique. A periodic switching of the elements leads to generation of sideband components in the frequency domain. The right-hand circular polarization (RHCP) and the left-hand circular polarization (LHCP) are synthesized over the first negative sideband frequency and the first positive sideband frequency, respectively, in wide frequency band. The TMAA used in the receiving mode provides conversion of the polarization-diversity into the frequency-diversity, therefore enables simultaneous reception and automatic separation of two electromagnetic waves which have the same frequency, however, mutually orthogonal senses of polarization.