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Simple Summary: The insect epidermis covers multiple parts of the insect body, fulfilling both structural and protective roles. Primarily composed of chitin and epidermal proteins, the insect epidermis displays considerable diversity among insects. The CPR family, the largest and most diverse group of cuticular protein (CP) genes identified to date, plays crucial roles in insect development, including body length regulation and cuticle formation. Steroid hormones, such as ecdysteroids, regulate the expression of epidermal proteins. In addition, the insecticide Methoxyfenozide mimics the action of 20E, thereby affecting insect growth. Our study on Heortia vitessoides Moore elucidates the role of HvCP3L and offers novel insights into pest management strategies for Aquilaria sinensis (Lour.) Spreng. Cuticle proteins (CPs) constitute a multifunctional family; however, the physiological role of Cuticle Protein 3-like (CP3L) in Heortia vitessoides Moore remains largely unclear. In this study, we cloned the HvCP3L gene from the transcriptional library of Heortia vitessoides Moore. RT-qPCR results revealed that HvCP3L exhibited high expression levels during the larval stage of Heortia vitessoides Moore, particularly at the L5D1 stage, observed in both larval and adult heads. Through RNA interference, we successfully silenced the HvCP3L gene, resulting in a significant reduction in the survival rate of Heortia vitessoides Moore, with the survival rate from larvae to adults plummeting to a mere 17.7%, accompanied by phenotypic abnormalities. Additionally, we observed that the knockdown of HvCP3L led to the inhibition of genes in the chitin pathway. Following exposure to methoxyfenozide stress, the HvCP3L gene exhibited significant overexpression, coinciding with phenotypic abnormalities. These findings underscore the pivotal role of HvCP3L in the growth and development of Heortia vitessoides Moore. [ABSTRACT FROM AUTHOR]

Background: Preoperative neoadjuvant chemoradiation (nCRT) has been the standard treatment for locally advanced rectal cancer. Serum biomarkers to stratify patients with respect to prognosis and response to nCRT are needed due to the diverse response to the therapy.Methods: Thirteen paired pre- and post-nCRT sera from rectal cancer patients were analyzed by isobaric tags for relative and absolute quantitation (iTRAQ) method. Twenty-five proteins were selected for validation by parallel reaction monitoring (PRM) in ninety-one patients.Results: Totally, 310 proteins were identified and quantified in sera samples. Reactome pathway analysis showed that the immune activation-related pathways were enriched in response to nCRT. Twenty-five proteins were selected for further validation. PRM result showed that the level of PZP was higher in pathological complete response (pCR) patients than non-pCR patients. The Random Forest algorithm identified a prediction model composed of 10 protein markers, which allowed discrimination between pCR patients and non-pCR patients (area under the curve (AUC) = 0.886 on testing set). Higher HEP2 and GELS or lower S10A8 in baseline sera were associated with better prognosis. Higher APOA1 in post nCRT sera was associated with better disease-free survival (DFS).Conclusions: We identified and confirmed a 10-protein panel for nCRT response prediction and four potential biomarkers HEP2, GELS, S10A8 and APOA1 for prognosis of rectal cancer based on iTRAQ-based comparative proteomics screening and PRM-based targeted proteomic validation. [ABSTRACT FROM AUTHOR]

This article presents a dual-band closed-slot multiple-input multiple-output (MIMO) antenna for terminal wireless applications. By simply inserting additional slots between the closely spaced parallel-arranged radiation slots, the signal impedances of common mode (CM) and differential mode (DM) can achieve similar status, and the strong mutual coupling effect is then eliminated. The proposed slot antenna pair shows good isolation of better than 20 dB across the desired Wi-Fi bands. In addition to the one-wavelength slot antenna, flexible extension to a more compact half-wavelength slot pair is given for future industrial design (ID), which provides further validation of the method. We fabricate the $4\times4$ MIMO antenna system constituted by two sets of one-wavelength closed-slot pairs. The experimental results show that the proposed MIMO antenna can offer isolation of better than 18 dB, an envelope correlation coefficient (ECC) of lower than 0.1 between all ports, and a wide −3 dB efficiency bandwidths across the desired bands. The results confirm that the proposed antenna is a viable candidate for Wi-Fi communications inside routers. [ABSTRACT FROM AUTHOR]

The huge proliferation of the antenna number brought by 5G greatly increases the pressure of the bezels of the 5G terminals. To release the pressure, planar four-antenna module with miniaturization and wideband performance that can be implemented on the back cover is proposed in this article. Four identical dual-mode PIFAs are arranged in a sequentially rotated style and the whole antenna appears in a circular shape. Each antenna element is a slotted quasi-quarter circle with one inner edge shorted and the other two edges left open, and it is coupled fed by an L-shaped microstrip line. A cross line that connects all the four elements together is used to improve the isolation of the neighboring elements. The four-antenna module covering N77 is with the diameter of 30.6 mm and height of 2 mm. The measured results show that for all the four antenna elements, the −6 dB impedance bandwidths cover 3.3–4.2 GHz, all the isolations are better than 9.7 dB, the average total efficiencies are between 36% and 40%, and envelope correlation coefficients (ECCs) are lower than 0.5. To the best of the authors’ knowledge, this is the smallest four-antenna module covering 3.3–4.2 GHz. [ABSTRACT FROM AUTHOR]

A dual‐band liquid cylindrical dielectric resonator antenna with pattern diversity at two different frequency bands is proposed using the lower order and higher order modes of the HEM and TM modes namely HEM11δ, HEM12δ+1, HEM31δ+1, HEM13δ, TM01δ, and TM02δ. The proposed antenna is designed to cover the GPS L2 band and the lower Wi‐Fi band at 1.227 and 2.4 GHz frequencies, respectively. The HEM modes which constitute the primary radiating modes achieved around 20.84% and 19.35% impedance bandwidth at lower and higher bands, respectively. In the later stage, beam‐steering is performed, whereby the realised broadside HEM modes at both lower and higher bands were passively steered with simple physical re‐orientation of the antenna structure. For this, the liquid's natural fluidic property of adhering to gravity is taken as an advantage which makes the proposed antenna adaptively steer its radiation pattern always towards the sky, irrespective of the tilt angle of the antenna. This concept of passively steering two modes at two different frequency bands without the use of any mechanical, electrical, or other associated components is presented for the first time. [ABSTRACT FROM AUTHOR]

In this paper, a novel six-mode loop antenna covering 660–1100, 1710–3020, 3370–3900, and 5150–5850 MHz has been proposed for the application of long-term evolution (LTE) including the coming LTE in unlicensed spectrum and LTE-Licensed Assisted Access. Loop antennas offer better user experience than conventional planar inverted-F antennas (PIFAs), inverted-F antennas (IFAs), and monopole antennas because of their unique balanced modes ( $1\lambda $ , $2\lambda , \ldots $ ). However, the bandwidth of loop antennas is usually narrower than that of PIFA/IFA and monopole antennas due to these balanced modes. To overcome this problem, a novel monopole/dipole parasitic element, which operates at an unbalanced monopole-like $0.25\lambda $ mode and a balanced dipole-like $0.5\lambda $ mode, is first proposed for loop antennas to cover more frequency bands. Benefiting from the balanced mode, the proposed parasitic element is promising to provide better user experience than conventional parasitic elements. To the best of the authors’ knowledge, the balanced mode for a parasitic element is reported for the first time. The proposed antenna is able to provide excellent user experience while solving the problem of limited bandwidth in loop antennas. To validate the concept, one prototype antenna with a size of $75 \times 10\times 5$ mm3 is designed, fabricated, and measured. Both simulations and experimental results are presented and discussed. Good performance is achieved. [ABSTRACT FROM AUTHOR]

Simple Summary: Heortia vitessoides Moore is a leaf-eating pest that affects Aquilaria sinensis. In the outbreak period, the leaves of Aquilaria sinensis can be eaten up in a short time, resulting in the death of trees and great economic losses. Chitin is the main component of insect cuticle, peritrophic membrane, and tracheal intima. Chitin synthesis in insects is a complex process that requires the cooperation of many enzymes. Chitin synthase is one of the key enzymes in the process. Chitin synthase is divided into two types: chitin synthase A gene (Chsa) and chitin synthase B gene (Chsb). Chsb is mainly responsible for the tissue synthesis of chitin in midgut peritrophic membrane. It was found that the expression of HvChsb was inhibited, the growth and development were abnormal, and the mortality rate was increased. These findings provide a reference for the prevention and control of the pest from the perspective of gene manipulation. The chitin synthase B gene is a key enzyme in the chitin synthesis of insect peritrophic matrix (PM), which affects insects' feeding behavior. The chitin synthase B gene was cloned from the transcription library of Heortia vitessoides Moore. RT-qPCR showed that HvChsb was highly expressed in the larval stage of H. vitessoides, especially on the first day of the pre-pupal stage, as well as in the midgut of larvae and the abdomen of adults. After starvation treatment, HvChsb was found to be significantly inhibited over time. After 48 h of starvation, the feeding experiment showed that HvChsb increased with the prolongation of the re-feeding time. The experimental data showed that feeding affected the expression of HvChsb. HvChsb was effectively silenced via RNA interference; thus, its function was lost, significantly decreasing the survival rate of H. vitessoides. The survival rate from larval-to-pupal stages was only 43.33%, and this rate was accompanied by abnormal phenotypes. It can be seen that HvChsb plays a key role in the average growth and development of H. vitessoides. [ABSTRACT FROM AUTHOR]

A fold monopole/dipole/loop antenna offers unique advantages over a conventional Planar Inverted-F Antenna (PIFA) and monopole antenna for a mobile cellular device. Perhaps the most significant benefit is the fact that up to three resonant modes could be generated in a single continuous loop structure. In this paper, a novel hexa-band internal folded monopole/dipole/loop antenna has been proposed. The proposed antenna has four resonances in which three of them are 0.5\lambda, 1\lambda and 1.5\lambda modes. The distinctive feature of the antenna is an extra 2\lambda folded dipole mode, which has not been reported so far, is excited and utilized. All these four modes can be employed to cover the Low LTE700/GSM850/900 Band (LB: 698–960 MHz) and the High GSM1850/1900/UMTS2100 Band (HB: 1710–2170 MHz). The proposed loop antenna has been simulated, prototyped and tested. It is shown that the numerically simulated results are in close agreement with the experimental prototype results and proved that the antenna operates as proposed. [ABSTRACT FROM PUBLISHER]

The key challenge in cancer treatment is prevention of metastatic disease which is therapeutically resistant and carries poor prognoses necessitating efficacious prophylactic approaches that prevent metastasis and recurrence. It is previously demonstrated that cowpea mosaic virus (CPMV) induces durable antitumor responses when used in situ, i.e., intratumoral injection. As a new direction, it is showed that CPMV demonstrates widespread effectiveness as an immunoprophylactic agent – potent efficacy is demonstrated in four metastatic models of colon, ovarian, melanoma, and breast cancer. Systemic administration of CPMV stimulates the innate immune system, enabling attack of cancer cells; processing of the cancer cells and associated antigens leads to systemic, durable, and adaptive antitumor immunity. Overall, CPMV demonstrated broad efficacy as an immunoprophylactic agent in the rejection of metastatic cancer. [ABSTRACT FROM AUTHOR]

Proposes and analyzes a thin-film superconducting meander patch antenna coupled by an H-shaped aperture. Principle of meander patch antennas; Discussion of the cavity model for analyzing meander patch; Computation of radiation patterns of copolarization for the meander patch; Evaluation of the radiation efficiencies of the antennas.

Addresses some of the perceived problems with high temperature superconducting microstrip antennas. Method of prediction of the center frequency; Analytical expression for the farfield radiation pattern of the H microstrip antenna; Flexibility and multifunctionality of the microstrip antenna.

To meet the demands of the new frequency bands and the $4\times 4$ multiple-input multiple-output (MIMO) specification brought by fifth generation (5G), a triple-band microstrip patch antenna and its four-antenna module are proposed. Based on the half-mode microstrip patch, the first three modes of TM1/2,0, TM1/2,1, and TM3/2,0 that can be independently tuned are engineered to cover the three Chinese 5G bands (N41/N78/N79). The proposed triple-band microstrip patch antenna with the volume of $33.5\times 32.5\times 4$ mm3 shows the −6 dB frequency bands of 2.47–2.75 GHz, 3.39–3.60 GHz, and 4.69–5.10 GHz, which makes a nice compromise between antenna volume and impedance bandwidths. Four such patches are arranged in a sequentially rotated style to constitute the triple-band four-antenna module, which is with the volume of $71\times 71\times 4$ mm3. Measured results of the module show high performance. The reflection coefficients of the four elements are almost identical: the bandwidths are 2.50–2.75 GHz, 3.41–3.62 GHz, and 4.68–5.01 GHz; all the isolations are better than −13.3 dB; the average total efficiencies of the four elements are between −1.41 and −1.11 dB, −2.45 and −2.10 dB, and −1.81 and −1.53 dB for N41, N78, and N79, respectively; and all the envelope correlation coefficients (ECCs) are lower than 0.07. [ABSTRACT FROM AUTHOR]

This article proposes a novel design of the dual-band antenna pair. Starting from the single-band antenna pair composed of T-shaped monopole and T-shaped slot that are intersected with each other, orthogonal T-monopole and odd-symmetrical slot modes are excited. By adding symmetrical low-pass high-stop filters into the horizontal stub of the T-monopole and high-pass low-stop filters into the gap of the T-slot, an extra mode is introduced for each antenna, producing dual-band operation. Impedance bandwidths and radiation efficiencies of both bands can be adjusted flexibly using the filters. A detailed design guideline is given. The dual-band antenna pair operating at partial N78 (p-N78, 3.4~3.6 GHz) and partial N79 (p-N79, 4.8~4.9 GHz) is with a footprint of $15\times 6$ mm2. The measured results show that the average efficiencies are both −3.4 dB at p-N78/p-N79 for the odd-symmetrical slot and −2.8 dB/−3.7 dB at p-N78/p-N79 for the T-monopole, isolations are better than −16.8 dB at p-N78 and −11.8 dB at p-N79, and ECCs are lower than 0.1 at p-N78 and 0.2 at p-N79. The proposed dual-band antenna pair exhibits great potential to be applied in the fifth-generation (5G) multiple-input multiple-output (MIMO) terminal. [ABSTRACT FROM AUTHOR]

The mechanism for the radiation efficiency local minimum in antennas, especially for open-slot antennas and T-shaped antennas, has been investigated. It is found that the local minimum in those antennas always corresponds to an ideal differential mode. Furthermore, the frequency position of the ideal differential mode is decided by the parasitic parts of the antennas. Simple methods for estimating the local minimum position are proposed based on the mechanism we have found. In addition, the duality relation between those two types of antennas is also discussed. Our findings provide a guideline for designing mobile phone antennas with improved efficiency. [ABSTRACT FROM AUTHOR]

This paper describes the design and testing of a multiple-in multiple-out (MIMO) antenna for metal-frame smartwatch applications. The antenna operates from 2.4 to 2.49 GHz, which can cover Bluetooth/WiFi band. The design procedure is based on the theory of characteristic modes and it is discussed thoroughly. By employing a pair of degenerated modes to design the MIMO antenna, a high port-to-port isolation can be achieved over the operating frequency band. Simulated and measured results are presented to verify the antenna design. Furthermore, the antenna has a low envelope correlation coefficient and a high effective diversity gain even when it is mounted on the human phantom. Hence, the proposed antenna proves to be a good candidate for smartwatch applications. [ABSTRACT FROM AUTHOR]

In the current study, corn stalk rinds were used as feedstock for the production of solid-fuel pellets. In an effort to comprehensively analyze the effects of different operational parameters on the physical properties of pellets, response surface methodology (RSM) was employed in conjunction with a Box–Behnken experimental design (BBD). By assessing multiple variables simultaneously and examining their interactions, BBD facilitates the development of a reliable response model that can predict how changes in independent variables will impact response variables. The recorded responses included relaxed density, mechanical durability, and compressive strength. Based on the results, greater R2 values of 0.9467, 0.8669, and 0.9196, could be, respectively, attained for the quadratic regression models. The analysis of variance revealed that all independent variables had significant effects on the responses. The optimal processing condition for the pellets was established by determining the ideal combination of operational parameters. The process entailed the choice of a particle dimension measuring 0.5 mm, a moisture level of 11.35%, the application of heat at 125.7 °C on the die, and the utilization of a molding pressure of 154.2 MPa. Based on these factors, the predicted response values were determined to be 1639.61 kg/m3 for relaxed density, 97.95% for mechanical durability, and 10.18 MPa for compressive strength. The values obtained experimentally under the optimized conditions were similar to the predicted values with a desirability value of 1.00. [ABSTRACT FROM AUTHOR]

In order to reduce the noble metal palladium dosage in the preparation of CL-20 so as to reduce its production cost, several carbon supports were prepared successfully using the hydrothermal carbonization method in the absence or presence of urea using microcrystalline cellulose (MC) as the carbon source, and the corresponding Pd(OH)2/C catalysts were fabricated using the deposition–precipitation method, which showed high activity in the debenzylation reaction of hexabenzylhexaazaisowurtzitane (HBIW) and tetraacetyldibenzylhexaazaisowurtzitane (TADB). It was found that all the catalysts showed a high efficiency in the debenzylation of HBIW, indicating that the structure of the used carbon supports had a limited impact on the catalyst performance in this reaction. On the contrary, the activities of the catalysts in the debenzylation of TADB were quite different. The results of the nitrogen sorption isotherm measurement (BET), scanning electron microscope (SEM), scanning transmission electron microscopy (STEM), powder X-ray diffraction (XRD), element analysis and temperature programmed desorption (TPD), as well as X-ray photoelectron spectra (XPS) characterizations of the supports and catalysts, showed that the relatively high activity of Pd/HTC in the debenzylation of TADB was related to the high Pd dispersion and novel mesoporous structure, while the further higher activity and stability of Pd/HTC-N1:1 in the same reaction were related with its high Pd dispersion, high total oxidized Pd species, and high surface pyridinic N contents as well as the eggshell distribution of Pd species on the support. [ABSTRACT FROM AUTHOR]

In this paper, a novel reconfigurable open slot antenna has been proposed for LTE smartphone applications to cover a wide bandwidth of 698–960 and 1710–2690 MHz. The antenna is located at the bottom portion of the mobile phone and is integrated with metal rim, thereby occupying a small space and providing mechanical stability to the mobile phone. Varactor diode is used to cover the lower band frequencies, so as to achieve a good frequency coverage and antenna miniaturization. The operational principles of the antenna are studied and the final design is optimized, fabricated, and tested. It has achieved the desired impedance bandwidth and the total efficiency of minimum 50% in free space throughout the required bands. The antenna performance with mobile phone components and human hand is also been studied. Furthermore, the SAR in a human head is investigated and is found to be within allowable SAR limits. Finally a multiple-input multiple-output antenna configuration with high isolation is proposed; it has an identical reconfigurable open slot antenna integrated at the top edge of the mobile phone acting as the secondary antenna for 698–960 and 1710–2690 MHz. Thus the proposed antenna is an excellent candidate for LTE smartphones and mobile devices. [ABSTRACT FROM AUTHOR]

In this communication, the design procedure of a wideband antenna with omnidirectional radiation pattern is demonstrated based on the theory of characteristic modes. Consisting of a dipole and a loop antenna, the antenna has a very simple structure. A wide impedance bandwidth is obtained because of the simultaneous excitation of the antenna’s first two modes. Meanwhile, due to the fact that these two modes share a similar omnidirectional radiation pattern, a stable radiation pattern is also achieved across the operating frequency band. In order to identify the antenna’s different modes, a characteristic mode analysis of the antenna is carried out first. Then, a feed configuration is specifically designed to excite the desired modes. To validate the antenna design, a prototype was fabricated and tested. Measured results agree well with the simulated ones. Measurement shows that a wide impedance bandwidth of 44.2% with \vert \textS11\vert < -10 dB (1.85–2.9 GHz) and stable radiation patterns at both E-plane and H-plane were achieved over the operating frequency band. [ABSTRACT FROM PUBLISHER]

This article presents a dual-band and dual-polarized microstrip antenna array with broadside beam scanning ability for millimeter-wave applications. Within a compact multilayer structure, wide bandwidth and high port isolation are achieved by using double-layer gridded patches with three groups of metallic via-fences. For beam scanning purpose, a prototype of $2 \times 2$ array is designed, fabricated, and tested. The experimental results agree well with the simulations. For both orthogonal polarizations, the −10 dB bandwidth covers 23.3–31.7 and 42.5–46.5 GHz with average gains of 12 and 13.1 dBi, respectively. A 3 dB beam scanning angle from −51° to 43° at 27 GHz and −28° to 30° at 45 GHz is obtained. The proposed array provides dual-band and wideband properties for dual orthogonal polarizations with competitive beam steering range and compact dimensions, as a feasible solution for fifth-generation (5G) millimeter-wave mobile communications. [ABSTRACT FROM AUTHOR]

In this article, an endfire dual-polarized phased antenna array with small ground clearance is proposed for the fifth-generation (5G) millimeter-wave (mmW) applications with a wide bandwidth. In this array, each antenna element consists of a dipole fed by a microstrip line for horizontal polarization and an H-plane horn using substrate-integrated waveguide (SIW) for vertical polarization. To achieve a wide bandwidth for vertical polarization, two metal vias are added at the aperture of the horn antenna. Then, a four-element antenna array is designed by partially overlapping the aperture of each horn element. A prototype has been fabricated using multilayer printed circuit board (PCB) process. The measured results agree well with the simulated ones. The antenna is with an impedance bandwidth of $\vert \text{S}_{11}\vert < -10$ dB from 24.4 to 29.5 GHz for both polarizations. The maximum gains of vertical and horizontal polarizations are 9.16 and 9.27 dBi, with the scanning angle from −34° to 33° for both polarizations with gain deterioration less than 3 dB. The proposed antenna is a promising solution for 5G mmW cellphones or antenna-in-package applications. [ABSTRACT FROM AUTHOR]

In this article, a general decoupling method based on a new perspective of common mode (CM) and differential mode (DM) cancellation is proposed. For two closely spaced antennas, the mutual coupling effect can be analyzed and solved by exciting them simultaneously with in-phase (CM) and out-of-phase (DM) signals. It is theoretically proved that, if CM and DM impedances are the same, the mutual coupling effect between two separated antennas can be totally eliminated. Therefore, we can solve the coupling problem by CM and DM impedance analysis and exploit the unique field properties of characteristic modes to assist in antenna decoupling in a physical intuitive way. To validate the feasibility of this method, two practical design examples, including the decoupling between closely spaced dipole antennas and planar inverted-F antennas, are proposed. Both design examples have demonstrated that the proposed method can provide a systemic design guideline for antenna decoupling and achieve better decoupling performance compared to the conventional decoupling techniques. We forecast the proposed decoupling scheme, with a simplified decoupling procedure, has great potential for the applications of antenna arrays and multi-input multi-output (MIMO) systems. [ABSTRACT FROM AUTHOR]

For the first time, zero-ground-clearance dual antenna pair with high isolation and balanced high performance is proposed. A T-shaped monopole intersects with a T-shaped slot that is etched on a large ground edge, constituting the CPW-fed dual antenna pair. By exploiting the odd and even modes of the CPW structure, two orthogonal characteristic modes including the in-phase current and monopole modes can be excited, generating high port isolation. Both modes are unbalanced mode, which means that the ground currents can be fully excited, so the two antennas are with balanced high performance. A sub-6 GHz antenna pair that occupies a footprint of $15\times 7$ mm2 ($0.18\,\,\lambda \,\times 0.08\,\,\lambda$) is analyzed and the simulated results show an isolation of better than −24 dB and an envelope correlation coefficient (ECC) of lower than 0.0016, −6 dB bandwidths of 230 and 240 MHz, and average efficiencies of 57.9% and 57.4%. A four-antenna multiple-input multiple-output (MIMO) array is fabricated and measured to verify the feasibility. The measured isolations and ECCs of the two modes are, respectively, better than −20.0 dB and 0.04, −6 dB bandwidths are 230 MHz/240 MHz and 220 MHz/230 MHz, and average efficiencies are 54.5%/50.2% and 49.9%/48.6%. The proposed dual antenna pair exhibits a great potential for 5G MIMO smartphone application. [ABSTRACT FROM AUTHOR]

In this article, a novel self-decoupled multiple-input multiple-output (MIMO) antenna pair with a shared radiator is proposed for fifth-generation (5G) smartphones. In our approach, a radiator is directly excited by two feeding ports, and interestingly, the two ports are naturally isolated across a wide bandwidth without using any extra decoupling structures. To offer a deep physical insight of the self-decoupling mechanism, a mode-cancellation method based on the synthesis of common and differential modes is developed for the first time. The proposed self-decoupled antenna pair shows a good isolation of better than 11.5 dB across the 5G N77 band (3.3–4.2 GHz) with a radiation pattern diversity property. Based on the self-decoupled antenna pair, an $8 \times 8$ MIMO antenna system, constituted by four sets of antenna pairs, is simulated, fabricated, and measured to validate the concept. The experimental results demonstrate that the proposed $8 \times 8$ MIMO system can offer an isolation of better than 10.5 dB between all ports and a high total efficiency of 63.1%–85.1% across 3.3–4.2 GHz. With the advantages of self-decoupling, shared radiator, simple structure, wide bandwidth, and high efficiency, the proposed design scheme exhibits promising potential for the future highly integrated MIMO antennas for 5G smartphones. [ABSTRACT FROM AUTHOR]

A novel concept of antenna design, termed differential mode/common mode (DM/CM) design, is proposed to achieve a highly integrated multi-input multi-output (MIMO) antenna unit in mobile terminals. The inspiration comes from a dipole fed by a differential line which can be considered a DM feed. What will happen if the DM feed is transformed into a CM feed? Some interesting features are provided in this article. By symmetrically placing one DM antenna and one CM antenna together, a DM/CM antenna can be achieved. Benefitting from the coupling cancellation of antiphase currents and the different distributions of the radiation currents, a DM/CM antenna can obtain high isolation and complementary patterns, even if the radiators of the DM and CM antennas are overlapped. Therefore, good MIMO performance can be realized in a very compact volume. To validate the concept, a miniaturized DM/CM antenna unit is designed for mobile phones. The 24.2 dB isolation and complementary patterns are achieved in the dimension of $0.330 \lambda _{0} \times 0.058\lambda _{0} \times 0.019 \lambda _{0}$ at 3.5 GHz. One $8 \times 8$ MIMO antenna array is constructed by using four DM/CM antenna units and shows good overall performance. The proposed concept of DM/CM design may also be promising for other applications that need high isolation between closely packed antenna elements and wide-angle pattern coverage. [ABSTRACT FROM AUTHOR]

This paper proposes a polarization-orthogonal co-frequency dual antenna pair suitable for fifth-generation (5G) multiple-input multiple-output (MIMO) smartphone with metallic bezels. The proposed spatial-reuse dual antenna pair consists of a split on the metallic bezel and a slot on the mainboard ground, where the slot is centered on the split. Two orthogonal degenerate characteristic modes operating at half wavelength including in-phase current and slot modes can be excited on the same antenna structure. An end-shorted microstrip line that crosses the split is used to excite the in-phase current mode, producing $y$ -polarized radiation, while a symmetrical slot-centered Y-shaped feeding network with its shorted ends crossing the slot is adopted to excite the slot mode, producing $x$ -polarized radiation. To the best of authors’ knowledge, this is the first time that a co-frequency dual antenna pair suitable for smartphone with metallic bezels is proposed. A sub-6 GHz dual antenna pair operating at 3.5 GHz that occupies a footprint of $25 \times 7 \times 1.5$ mm3 shows a simulated isolation better than −24.1 dB without any external decoupling measures and an envelope correlation coefficient (ECC) lower than 0.008. A four-antenna MIMO array is fabricated and measured to verify the feasibility. Across the operation band, the measured isolation of the antenna pair is better than −20.1 dB and other isolation levels are all better than −12.7 dB, the ECCs of any two antennas are lower than 0.13, and the total efficiency range of the four antennas is 35.2%~64.7%. The proposed dual antenna pair exhibits a great potential to be applied in future 5G MIMO smartphone. [ABSTRACT FROM AUTHOR]

In , there are some mistakes in the antenna dimensions in on page 2672 and on page 2674. These two figures should be corrected as follows: [ABSTRACT FROM AUTHOR]

A new miniature circular high-impedance surface (HIS) is used to design a compact and low-profile multi-in multi-out (MIMO) antenna for wearable applications. The antenna is designed to operate from 2.4 to 2.49 GHz for wireless local area network application. By employing a pair of degenerated characteristic modes of a circular loop antenna, the MIMO antenna can achieve a good port-to-port isolation (>15 dB) without increasing its geometric size. A four-element HIS is chosen to match the antenna profile, and a 2 dBi antenna gain improvement is observed. The design was optimized considering the effect of packaging and then a prototype with the optimal parameters was fabricated and tested. Measurement results are in good agreement with simulation results. Furthermore, the loading effect due to lossy human tissue is also considered and the results show that the antenna has a robust performance against the human phantom and a low specific absorption rate can also be obtained. [ABSTRACT FROM AUTHOR]