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This paper proposes a robust model for the accurate behavioral modeling and digital predistortion (DPD) of wideband radio-frequency power amplifiers (PAs). It is constructed using a complexity-reduced generalized memory polynomial (MP) (GMP) (CR-GMP) connected with a nonlinear memory effect (NME) subblock in parallel. The CR-GMP is a complexity-reduced but accuracy-degraded version of the conventional GMP, and its performance is augmented by the extra NME subblock. Hence, the proposed model is termed as augmented CR-GMP (ACR-GMP). The resultant ACR-GMP model can achieve comparable performance as the GMP model, but with much fewer coefficients and lower complexity. Its performance is experimentally assessed both in forward modeling and DPD linearization. Comparisons are conducted between the ACR-GMP model and some state-of-the-art models, such as the MP, the PLUME, and the GMP. Experimental results have been given for a 1.9-GHz 35-W peak-power GaN Class-AB PA driven by two signal scenarios: a 15-MHz bandwidth long-term-evolution signal and a 20-MHz bandwidth widebandcode-division-multiple-access 1001 signal (with the middle two carriers OFF). All the results show that the ACR-GMP model outperforms both the MP and the PLUME models in terms of performances and the GMP model in terms of complexity (at comparable performances).Index Terms-Behavioral modeling, digital predistortion (DPD), generalized memory polynomial (MP) (GMP), memory effect, MP, power amplifiers (PAs).

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Chiral calix[4]arenes bearing long tertiary alkyl groups at the upper rim and S-1-phenylethylamine groups at the lower rim can form heat-set gels and egg-like vesicles enantioselectively with d-2,3-dibenzoyltartaric acid in cyclohexane, which is the first example of heat-set gels resulting from difference in interactions between two component gelators: in addition, the diameter of vesicles decreased with the increase in length of alkyl groups, which could be used to control the size of the vesicles.

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A series of azobenzene-tethered polyhedral oligomeric silsesquioxane (POSS) derivatives, i.e. monoazobenzene-substituted POSS (MonoAzo-POSS), bisazobenzene-substituted POSS (BisAzo-POSS) and triazobenzene-substituted POSS (TriAzo-POSS), were synthesized through the amidation acidylation of aminopropylisobutyl POSS and benzoic acid derivatives (AzoMs) with one, two and three azobenzene groups (AzoM1, AzoM2 and AzoM3). Their structures were characterized by FT-IR, 1 H NMR, 13 C NMR and mass spectra, and their thermal stability and photoresponsive behaviors in DMF solutions were evaluated with TGA, XRD and UV-vis spectra, respectively. The results indicated that the thermal stability and photoisomerization of azobenzenes could be effectively controlled by their molecular structure. In MonoAzo-POSS, the large steric hindrance of POSS destroys the molecular ordering and limits the molecular packing, contributing to its poor thermal stability. And the low molecular ordering of MonoAzo-POSS offers an azo group with large free space, and its trans-cis photoisomerization rate increases accordingly. But, in BisAzo-POSS and TriAzo-POSS, the incorporation of POSS units does not impact on the regularity of azobenzenes obviously, and the hindrance effect of nanosize POSS on the molecular motion plays a primary role in increasing their high thermal stability. Their photoisomerization rates decrease due to the steric hindrance of POSS and the unfolding structure of the azo moieties in BisAzo-POSS and TriAzo-POSS.