In this paper, a resistive-reactive series of continuous inverse modes is proposed for extending bandwidth of the series of Inverse continuous mode (SICM). A broadband class inverse F power amplifier (PA), which operates across 2.5-4.1 GHz (48.5% bandwidth), is designed by using bare GaN HEMT to prove this theory. Experiment results indicate that the PA mentioned above is able to output 9.1-18.4 W saturation power and the drain efficiency can reach 47%-75% in the whole interested band. The average output power of this designed PA is 14.2 W and the average drain efficiency is 60.1%.

In this letter, an on-chip bandwidth-agile film bulk acoustic resonator (FBAR) filter employing chipped fractal structure is proposed. First, by using the high longitudinal wave velocity of the BaZn2Fe $_{{16}{-}{x}}$ ScxO27 (Ba-Zn-Fe-Sc-O) functional thin film, we have realized the resonant frequency in the millimeter wave region of the 5G-FR2 communication band. Then, in order to control the bandwidth of the proposed filter, we have proposed a fractal-shaped resonator topology with chipped sides. Two resonant modes with the resonant frequencies ${f}_{s{1}}$ and ${f}_{s{2}}$ have been produced. The frequency of the second mode ${f}_{s{2}}$ can be determined accurately by the ratio of the fractally chipped sides. Thus, the bandwidth can be controlled by changing the ratios in the design process. The proposed filter is simulated and measured. The measured results are in good agreement with the simulated ones. The proposed filter can be applied in the millimeter wave band region of modern 5G communication systems.

In this article, a nonconformal and non-overlapping domain decomposition method (DDM) based on surface integral equation (SIE) is proposed for the electromagnetic (EM) scattering or radiation of multiscale metallic targets. In order to reduce the unknown amount of the conventional SIE for multiscale EM simulation, we apply curved triangular elements and higher order hierarchical vector (HOHV) basis functions to the SIE. Next, to increase the flexibility of geometrical modeling and accelerate the convergence of the presented SIE system for electrically large and multiscale metallic targets, a DDM scheme is further developed to employ a discontinuous Galerkin (DG) approach to glue conformal/nonconformal surface grids between adjacent subdomains. In addition, an interior penalty term is introduced to stabilize the DDM solution, and half edge-based HOHV basis functions are introduced to model the current associated with nonconformal surface elements. Meanwhile, the basis expansion and recombination (BER) technique is introduced to significantly accelerate the matrix-filling and improve the efficiency. The flexibility of basis order selection is further enhanced by the hierarchical characteristic of HOHV bases. Finally, several numerical results are provided to demonstrate the accuracy, efficiency, and flexibility of the proposed HO-DG-DDM.

This paper proposes a new control method to regulate the power flow into multiple receivers. This system consists of one transmitter controller and three receiver controllers. They work independently to decide the power distribution with their combined operation. The simulated and experimental models have been built, and the experimental results are in good agreement with the theoretical analysis results. The proposed method is robust, flexible, and generalizable, and can be employed under various wireless charging conditions.