Dual-mode Resonator Research Articles

Self-Confirming Magnetosomes for Tumor-Targeted T1 /T2 Dual-Mode MRI and MRI-Guided Photothermal Therapy.

Nanomaterials as T1 /T2 dual-mode magnetic resonance imaging (MRI) contrast agents have great potential in improving the accuracy of tumor diagnosis. Applications of such materials, however, are limited by the complicated chemical synthesis process and potential biosafety issues. In this study, the biosynthesis of manganese (Mn)-doped magnetosomes (MagMn) that not only can be used in T1 /T2 dual-mode MR imaging with self-confirmation for tumor detection, but also improve the photothermal conversion efficiency for MRI-guided photothermal therapy (PTT) is reported. The MagMn nanoparticles (NPs) are naturally produced through the biomineralization of magnetotactic bacteria by doping Mn into the ferromagnetic iron oxide crystals. In vitro and in vivo studies demonstrated that targeting peptides functionalized MagMn enhanced both T1 and T2 MRI signals in tumor tissue and significantly inhibited tumor growth by the further MRI-guided PTT. It is envisioned that the biosynthesized multifunctional MagMn nanoplatform may serve as a potential theranostic agent for cancer diagnosis and treatment.

Design of microstrip quint‐band lowpass–bandpass filters with flexible passband allocation

In this paper, newly proposed microstrip quint-band lowpass–bandpass filters are presented. The lowpass filter structure comprises a meandered transmission line and modified T-shaped resonators. Based on such an lowpass filter (LPF) structure, a quad-band λ/4 inductively-coupled dual-mode stub-loaded stepped impedance resonators BPF with one pair of a coupled I/O feeding line are parallelled on both sides of LPF to construct a quint-band lowpass–bandpass filter. By incorporating the parallel I/O coupled line and utilising multiple coupling paths, four bandpass bands can be fully controlled and designed independently. Specially, two distinct types of bandpass filters with different generating mechanisms are investigated and then combined to provide the quad-band responses. To validate the design concept, two types of quint-band lowpass–bandpass filters are designed, fabricated, and tested, where simulation results agree well with measurement results.

A Novel Double U-Slot Microstrip Patch Antenna Design for Low-Profile and Broad Bandwidth Applications

A low-profile double U-slot microstrip patch antenna with a wide operating bandwidth has been developed in this article. This design produces the dual radiative resonant modes adjacent to each even at the thickness of the antenna of <inline-formula> <tex-math notation="LaTeX">$0.02 {\lambda _{0}}$ </tex-math></inline-formula>. An extremely stable radiation gain that varied from 6.2 to 6.8 dBi is achieved within the whole operating band. In addition, detailed parametric studies in this article provide antenna engineers with simple approximate rules that result in an excellent first-pass design with prescribed characteristics requiring only minimal tuning. Finally, the proposed antenna with the thickness of <inline-formula> <tex-math notation="LaTeX">$0.04 {\lambda _{0}}$ </tex-math></inline-formula> is fabricated and measured. Simulated and measured results are found in good agreement with each other. They have evidently illustrated that the bandwidth is increased by 50&#x0025; compared to the traditional U-slot antenna. With the help of these simple design procedures and examples in this article, antenna designers could easily develop a low-profile broadband antenna.

A Narrowband 3-D Printed Invar Spherical Dual-Mode Filter With High Thermal Stability for OMUXs

A 3-D printed narrowband bandpass filter based on spherical dual-mode resonators is presented in this article. It is designed for output multiplexers (OMUXs) using high-<inline-formula> <tex-math notation="LaTeX">$Q$ </tex-math></inline-formula> spherical dual-mode resonators. Realization is by laser powder bed fusion (L-PBF) technology of Invar alloy chosen for its low coefficient of thermal expansion (CTE). Using PBF circumvents the alloy&#x2019;s manufacturability issues associated with its hardness in machining and free forming. Compared with polymer-based vat photopolymerization technology, PBF allows for direct metal manufacture of complex monolithic microwave components with better thermal-mechanical properties and higher power-handling capability. Using Invar can further help achieve high temperature stability of the filter in high-power operation. To demonstrate the proposed solution, detailed thermal-RF test at different temperatures was carried out. The experimental results of a 0.47&#x0025; fourth-order silver-plated Invar filter with two transmission zeros verify the design and manufacturing. An insertion loss of 1 dB and an effective temperature coefficient of less than 2 ppm/K were achieved.

Analysis of Dual-mode Resonators from Transmission Line Segments

Analysis of Dual-mode Resonators from Transmission Line Segments

Design and Analysis of a Compact GSM/GPS Dual-Band Bandpass Filter Using a T-Shaped Resonator

This study presents an ultracompact dual-band bandpass filter with controllable transmission zeros based on quarter-wave dual-mode resonator for GSM (global system for mobile communications) and GPS (global positioning system) wireless applications. The filter is made up of two quarter-wave resonators, which help to independently control the passbands. A direct feed resonator creates the first operating band, which serves as a feeding source for the interior resonator and operates at a higher frequency band. Therefore, a pair of transmission zeros can be energized between the two passbands, and high roll-off skirts are obtained. To reduce the size of the entire filter, the two resonators are bent and connected together through a hole in a metal base. The structure is symmetrical in nature, so both frequency bands can be obtained using the even-odd mode analysis method. For GSM applications, the center frequency of the first working band is 850 MHz, while for GPS wireless applications, the center frequency of the second working band is 1.57 GHz. Although there is a feed line (λg is based on a waveguide length of 850 MHz), the filter has been simulated and fabricated for verification, with an ultra-compact size of 0.10 λg × 0.09 λg (0.0095 λg 2). The simulation results and measured results match well, and the theory of the design concept is recognized.

Feasibility of Constructing an Automatic Meniscus Injury Detection Model Based on Dual-Mode Magnetic Resonance Imaging (MRI) Radiomics of the Knee Joint.

Objective To explore the feasibility of automatically detecting the degree of meniscus injury by radiomics fusion of dual-mode magnetic resonance imaging (MRI) features of sagittal and coronal planes of the knee joint. Methods This retrospective study included 164 arthroscopically confirmed meniscus injuries in 152 patients admitted to the Department of Orthopaedics of our hospital from July 2018 to March 2021. A total of 1316-dimensional radiomics signatures were extracted from single-mode sagittal and coronal plane images of menisci, respectively. Then, the sagittal and coronal plane features were fused to form a dual-mode joint feature group with a total of 2632-dimensional radiomics signatures. The minimum redundancy maximum relevance (mRMR) algorithm and the least absolute shrinkage and selection operator (LASSO) regression were used to select features and generate optimal radiomics signatures. The single-mode sagittal plane feature model (Model 1), single-mode coronal plane feature model (Model 2), and the combined sagittal and coronal plane feature model (Model 3) performance were tested by receiver operating characteristic (ROC) curves and Delong test. The calibration curve test was used to verify the reliability of radiomics signatures of the three models. Results The average intra- and interobserver intraclass correlation coefficients (ICCs) of the most significant 8-dimensional radiomics signatures of Model 1 and Model 2 were 0.935 (range 0.832-0.998) and 0.928 (range 0.845-0.998), respectively. All the three models had good detection performance; Model 3 had the most significant performance (the areas under the curve (AUCs) of training, and validation sets were 0.947 and 0.923, respectively), which was superior to Model 1 (AUCs of training set and validation set were 0.889 and 0.876, respectively) and Model 2 (AUCs of training set and validation set were 0.831 and 0.851, respectively). The detection probability of training and validation sets in the three models was highly consistent with the actual clinical probability. Conclusions It is feasible to establish a model for automatic detection of meniscus damage by means of radiomics. The detection performance of the dual-mode knee MRI model is better than that of any single-mode model, showing potent feature analysis ability and outstanding detection performance.

A sixth‐order SIW bandpass filter based on combining single‐ and dual‐mode cavities with high selectivity at Ka‐band

In this paper, a novel substrate integrated waveguide quasi-elliptic bandpass filter is proposed by combining single- and dual-mode cavities. Two single-mode cavities with TE101 mode are directly coupled to the dual-mode resonance cavity which employs a pair of disturbing metallic via-holes to make the resonant points of TE101 and TE102 mode in one passband. Based on the conventional box-like topology, two additional single cavities are used to achieve wider bandwidth and simplify the design difficulty. In addition to two transmission zeros (TZs) realized by the cross-coupling technology, nonreasoning node will generate an additional TZ at a higher frequency to improve the upper stopband performance. Finally, a sixth-order filter, having the passband frequency of 24.25–27.5 GHz for 5G application, with three TZs, is simulated, fabricated and measured to demonstrate and verify the proposed structure. The test results show the insertion loss is 1.7 and 3 dB bandwidth is 3.37 GHz. The three TZs improve out of band rejection of the filter.

A Compact Dual-band Planar Antenna Loaded with Magneto Dielectric Ferrite

In this paper, a compact dual-band planar antenna loaded with magnetodielectric ferrite is proposed for ISM/GSM/UMTS. Slot and ring structures are dual-resonant mode generators of the antenna. And the characteristic mode analysis is used for the modeling, analysis, and optimization of the proposed antenna. Because of the loading of a piece of rectangular Co22W hexaferrite medium, this antenna can be used in lower frequency bands. The electromagnetic parameters of this ferrite are measured by the transmission line method. Finally, the antenna is fabricated and measured. The operation frequency band (S&lt;11&lt;11−-10 dB) is determined to be 80 MHz (890–970 MHz) and 370 MHz (1.87–2.24 GHz) with the dual resonance frequencies of 925 MHz and 2.175 GHz, respectively, which is capable for ISM (915 MHz)/GSM900/UMTS applications.

An Invar Alloy SLM Printed Diplexer With High Thermal Stability

This paper presents a selective laser melting (SLM) 3-D printed Ku-band diplexer using dual-mode resonators with high thermal stability. The diplexer is designed using dual-mode dimpled ellipsoid resonators which enables the diplexer mechanically self-supported in fabrication. Hence, the design has higher compatibility with the SLM printing process and the design can be extended to multiplexers with more channels. The excellent thermal stability is benefited from both the 4J36 invar alloy material with a lower coefficient of thermal expansion (C.T.E) as well as the tailored SLM printing process. Electrical and thermal performances of the diplexer are measured, showing that the fabricated diplexer is with average insertion losses of 0.69dB/0.42dB, return losses of >14dB, and centre frequency shifts of 5.62MHz/3.75MHz (<0.04%) in the two channels after copper plating. The measured frequency shift is less than 0.5 MHz over 100∘ temperature change, which is equivalent to a C.T.E of 0.5 ppm.

Co-Design of Wideband Filtering Dielectric Resonator Antenna With High Gain

In this communication, a novel synthesis design method is proposed for designing a wideband filtering dielectric resonator antenna (FDRA) using multimode resonators (MMRs). To start with, the proposed FDRA composed of a tri-mode stub-loaded resonator as the feeding network and a rectangular dual-mode dielectric resonator (DR) as the radiator is introduced. Then, an exact synthesis and design procedure is proposed for facilitating to design this FDRA. Following that, an appropriate coupling topology is selected to allocate a composite quintuple-mode resonator to achieve a wideband operation for this FDRA. Finally, for an experimental verification, a prototype of the FDRA is designed, fabricated, and measured. The simulation and measurement results are in well accordance with each other, showing a good filtering performance from 2.2 to 3.1 GHz, an average gain of 9.1 dBi, and good out-of-band suppression.

Effective Combination of Isoniazid and Core-Shell Magnetic Nanoradiotherapy Against Gastrointestinal Tumor Cell Types.

IntroductionRadiotherapy is a conventional treatment for gastrointestinal tumors. However, its therapeutic effect might not be satisfactory because of factors such as radio-resistance of tumor cells and dose reduction applied to avoid damage to normal tissues. We developed a novel combination therapy involving the use of isoniazid (INH) and core-shell magnetic nanospheres (NPs) to enhance the efficacy of radiotherapy.MethodsMagnetic core-shell NPs were synthesized. The shell manganese dioxide (MnO2) reacted with intracellular glutathione to produce Mn2+, which decomposed hydrogen peroxide (H2O2) to hydroxyl radicals (·OH) in the presence of INH to produce sufficient amount of reactive oxygen species. In addition to this chemodynamic therapy, MnO2 catalyzed H2O2 to O2, which alleviated hypoxia in tumors and thus enhanced the effect of radiotherapy. In addition, iron oxide (Fe3O4) and reduced Mn2+ were potential candidates for T1–T2 dual-mode magnetic resonance imaging (MRI) with remarkable magnetic targeting ability.ResultsNPs exhibited efficient tumor targeting performance under the magnetic field and improved T1/T2 dual-mode MRI, which elevated oxygen levels without toxicity to the mice to achieve remarkable therapeutic outcomes, reaching a tumor inhibition rate of 93.2%. Moreover, chemodynamic therapy mediated by INH and NPs enhanced the therapeutic effect of radiotherapy both in vivo and in vitro.ConclusionThe results demonstrated that the combination of INH and NPs could be a novel strategy for radiosensitization with clinical potential.

A designing solution for bandpass filter using TE dual-mode resonator in waveguides

The article presents a design for a bandpass filter using TE dual-mode resonator. The design is based on the general scatting matrix of each discontinuity in the structure. Different propagation modes in the same waveguide section are used to represent the matrices to facilitate the design. On the basis of ultra-high frequency theory and simulation software tools, the authors have calculated the design of a 4th order bandpass filter using the resonances, and with two symmetrical transmission zeros.

A Broad Dual-Band Bandpass Filter Design Based on Double-Layered Spoof Surface Plasmon Polaritons

In this work, a broad dual-band bandpass filter is designed by applying double-layered spoof surface plasmon polaritons (DLSSPPs) as the main transmission line (MTL) and loading combined-stub dual-mode resonators (CSDMRs) onto the MTL with certain spaces. Each CSDMR consists of an open stub and a short stub that are connected in parallel. Efficient mode conversion between the quasi-transverse electromagnetic waves in the microstrip line and the spoof surface plasmon polaritons (SSPPs) on the double-layered surface plasmon waveguide is realized using gradient double-layered metal gratings and via the sector structure impedance matching technique. A parametric study of the CSDMR demonstrates that center frequencies and bandwidths can be controlled by varying the stub lengths and widths of the CSDMRs. A second-order dual-band filter is designed and fabricated, and simulated and experimental S-parameters agree well. A lower loss of the passband is achieved compared with the filters that apply single-layered SSPPs. The space between two CSDMRs is shortened because of the slow-wave effect of the DLSSPPs. The lowpass performance of the DLSSPPs exhibits good rejection from the cutoff frequency above.

Orchestrated Yolk-Shell Nanohybrids Regulate Macrophage Polarization and Dendritic Cell Maturation for Oncotherapy with Augmented Antitumor Immunity.

The protumoral and immunosuppressive tumor microenvironments greatly limit the antitumor immune responses of nanoparticles for cancer immunotherapy. Here, the intrinsic immunomodulatory effects of orchestrated nanoparticles and their ability to simultaneously trigger tumor antigen release, thereby reversing immunosuppression and achieving potent antitumor immunity and augmented cancer therapy, are explored. By optimizing both the composition and morphology, a facile strategy is proposed to construct yolk-shell nanohybrids (Fe3 O4 @C/MnO2 -PGEA, FCMP). The intrinsic immunomodulatory effects of FCMP are utilized to reprogram macrophages to M1 phenotype and induce the maturation of dendritic cells. In addition, the chemical, magnetic, and optical properties of FCMP contribute to amplified immunogenic cell death induced by multiaugmented chemodynamic therapy (CDT) and synergistic tumor treatment. Taking advantage of the unique yolk-shell structure, accurate T1 -T2 dual-mode magnetic resonance imaging can be realized and CDT can be maximized through sufficient exposure of both the Fe3 O4 core and MnO2 shell. Potent antitumor effects are found to substantially inhibit the growth of both primary and distant tumors. Furthermore, the strategy can be extended to the synthesis of other yolk-shell nanohybrids with tailored properties. This work establishes a novel strategy for the fabrication of multifunctional nanoplatforms with yolk-shell structure for effective cancer therapy with immunomodulation-enhanced antitumor immunity.

Design and Optimization of the Dual-Mode Lamb Wave Resonator and Dual-Passband Filter.

Radio frequency (RF) filters with multiple passbands can meet the needs of miniaturization and integration for 5G communications. This paper reports a dual-mode Lamb wave resonator (DLWR) and a dual-passband filter based on DLWRs. The DLWR consists of a piezoelectric film and two interdigital electrode (IDT) arrays with different thicknesses, which leads to the coexistence of two main modes in the resonator. The resonance frequencies of the two modes can be adjusted separately by changing the thicknesses of the IDTs, which greatly satisfies the requirements of the dual-passband filter. Four DLWRs with different electrode configurations are designed, and the influences of the periodic length and thicknesses of the IDTs on the performance of the DLWR are studied. When the thickness of the piezoelectric layer is 0.75 μm and the two thicknesses of the IDTs are 0.1 μm and 0.3 μm, the resonance frequency of the second main mode is 1.27 GHz higher than the resonance frequency of the first main mode in the DLWR. Furthermore, a dual-passband filter based on the proposed DLWRs is demonstrated with an insertion loss less than 1 dB and a band rejection of about 15 dB. Moreover, two passbands at 2.45 GHz and 3.88 GHz with bandwidths of 66 MHz and 112 MHz, respectively, are achieved. The presented DLWR shows a potential application that can be used to obtain RF filters with adjustable dual passbands.

SLA printed horn antenna with filtering network based on dual‐mode ellipsoid resonator

This paper presents a horn antenna with a 5th-order dual-mode ellipsoid resonator filtering network, fabricated by stereo lithography apparatus 3-D printing technic. The filtering part employs two dimpled ellipsoid dual-mode resonators, operating at the fundamental TM101 mode. Compared to the filters employing cylindrical resonators with tuning posts, the proposed filtering network is with lower loss (due to the high Qu resonator) and the performance is less sensitive to the fabrication errors. The antenna was demonstrated at Ku band (12–18 GHz), with a measured RL >10 dB across the passband of 14.6–15.4 GHz. The measured gain of the antenna is 11.4 dBi at 15 GHz and maximum in-band gain variation is 0.4 dB.

Design of Dual-Channel Filter Based on Dual-Mode Dielectric Resonators

In this brief, the design approach of dual-channel filter based on dual-mode dielectric resonator (DR) is proposed. A pair of orthogonal modes in dual-mode DR with the same and different frequencies are analyzed and applied to construct the two channel filtering responses independently. Meanwhile, the isolation between the two channels can be realized due to the orthogonality between the modes. Thus, the design process is simple and efficient. To verify the design approach, two prototypes with the same and different frequencies are designed. Meanwhile, the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3^{rd}$ </tex-math></inline-formula> -order dual-channel filter with different frequencies are also implemented and measured. The frequencies of the two designs are 1.54GHz and 1.53/1.68GHz, respectively. In each design, the return losses of the two channels are better than 14dB, the insertion losses are less than 0.68dB, and the band isolation is greater than 20dB. Meanwhile, the results also show that arbitrary filtering order and high design flexibility can be achieved.

Dual-Band Dual-Mode Dielectric Resonator Filtering Power Divider With Flexible Output Phase Difference and Power Split Ratio

The design of dual-band filtering power divider based on dual-mode dielectric resonator (DR) is investigated. The external quality factors ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q_{e}$ </tex-math></inline-formula> ) of two modes can be controlled independently, which makes the design procedure for arbitrary power split ratio simple and efficient. Meanwhile, the phase difference between the output ports can be adjusted to be in-phase or out-of-phase by altering the quadrants where the feeding probes are located. To improve the band-to-band isolation, the generation mechanism of the transmission zero between the two bands has been analyzed. Based on the analysis, the dual-band filtering power dividers with in-phase/out-of-phase outputs and equal/unequal power split ratio are proposed. All of them can be easily built by properly changing the location or the length of the feeding probes without increasing the circuit size. To verify the design concept, the above-mentioned prototypes are simulated. Some of them are implemented and measured. The measured results match well with the simulated responses, showing good performance, such as low loss and good band selectivity.

Synthesizing Radiation Properties of Dual-band Dual-mode High Gain Dielectric Resonator Antenna for Wireless Applications

Synthesizing Radiation Properties of Dual-band Dual-mode High Gain Dielectric Resonator Antenna for Wireless Applications