In this paper, a novel method for designing high-power filtering switches using dielectric resonators (DRs) is presented for the first time. The filtering switches consist of DRs and printed circuit ...boards. The latter are embedded in the metal cavity to enable the integration of p-i-n diodes. The ONand OFF-states are realized by controlling the p-i-n diodes which are put in the feeding lines or nonresonance nodes (NRNs). Electromagnetic field properties of the DR (at TE 11δ mode) and feeding line (or NRN) are studied and the coupling between them is investigated for guiding coupling control. In the ON-state, the filtering switches are equivalent to bandpass filters with no signal passing through the p-i-n diodes, which avoids additional loss introduced by p-i-n diodes and attains high power handling capability. In the OFF-state, the proposed filtering switches offer enhanced isolations by controlling the coupling of the filtering circuits, which differs from the conventional switches by turning off transistors or diodes. For demonstration, a DR-based filtering single-pole single-throw switch and a filtering single-pole double-throw switch are implemented. High selectivity, low ON-state loss and high OFF-state isolation are observed. The measured P 1dB is larger than 80 W, featuring high power handling capability.
In this article, quarter-mode substrate-integrated waveguide (QMSIW) filters featuring ultrawide stopband and flexibly allocated transmission zeros (TZs) are proposed. Eight higher modes with ...resonant frequencies up to 4.7 times of the fundamental mode are highly suppressed. It is realized by the combination of three approaches without extra circuit areas. First, a slot is cut in the first and last QMSIW resonators to make their resonant frequencies of higher modes different from those of other resonators. Second, avoid exciting the specific higher modes by setting the feed point in the area where the electric field strength of the higher modes is weak. Third, mismatch the higher modes when matching the passband. It is realized by using a stripline impedance transformer with its main body not exceeding the area of QMSIW resonators. Furthermore, except for the TZs derived by the classical cross-coupling matrix, two more independently controlled TZs are generated. The packaged filter is fabricated by using a benzocyclobutene (BCB)-based microelectromechanical systems (MEMS) process, which is suitable for millimeter-wave 3-D system-on-package (SOP) applications. The fabricated thin-film filter is measured with an insertion loss of 2.96 dB at 29.4 GHz and a fractional bandwidth (BW) of 17%. Higher mode suppressions up to 138.3 GHz are achieved.
This letter presents a novel tri-band bandpass filter (TB-BPF) based on proposed stubs loaded stepped-impedance resonator (SLSIR). The first three resonant modes of proposed SLSIR can be ...independently controlled by the shorted high-impedance section of SIR, the loaded open stub and the loaded shorted stub, respectively, resulting in the independency of central frequencies and return losses of three passbands. As an example, a TB-BPF operating at 0.9/1.8/2.45 GHz are designed and fabricated. Due to the cancelling effect of mixed electric and magnetic coupling, the virtual grounds existed in SLSIR and the introduced embedded open stub, six transmission zeros are realized around three passbands, resulting in the high passband selectivity and band-to-band isolation. The fabricated TB-BPF also has a compact size of 0.06λ g × 0.162λ g .
Organic metal halide hybrids (OMHHs) have attracted great research attention owing to their exceptional structure and property tunability. Using appropriate organic and inorganic metal halide ...components, OMHHs with controlled dimensionalities at the molecular level, from 3D to 2D, 1D, and 0D structures, can be obtained. In 0D OMHHs, anionic metal halide polyhedrons are surrounded and completely isolated by organic cations to form single crystalline “host–guest” structures. These ionically bonded organic–inorganic hybrid systems often exhibit the intrinsic properties of individual metal halide species, for instance, highly efficient Stokes‐shifted broadband emissions. In this progress report, the recent advances in the development and study of luminescent 0D OMHHs are discussed: from synthetic structural control to fundamental understanding of the structure–property relationship and device integration.
Zero‐dimensional organic metal halide hybrids (0D OMHHs) have emerged as highly promising photoactive hybrid materials with unique properties and applications in a variety of areas. This progress report discusses the recent advances in the development and study of luminescent 0D OMHHs, from synthetic structural control to fundamental understanding of the structure–property relationship and device integration.
The photophysical tuning is reported for a series of tetraphenylphosphonium (TPP) metal halide hybrids containing distinct metal halides, TPP2MXn (MXn=SbCl5, MnCl4, ZnCl4, ZnCl2Br2, ZnBr4), from ...efficient phosphorescence to ultralong afterglow. The afterglow properties of TPP+ cations could be suspended for the hybrids containing low band gap emissive metal halide species, such as SbCl52− and MnCl42−, but significantly enhanced for the hybrids containing wide band gap non‐emissive ZnCl42−. Structural and photophysical studies reveal that the enhanced afterglow is attributed to stronger π–π stacking and intermolecular electronic coupling between TPP+ cations in TPP2ZnCl4 than in the pristine organic ionic compound TPPCl. Moreover, the afterglow in TPP2ZnX4 can be tuned by controlling the halide composition, with the change from Cl to Br resulting in a shorter afterglow due to the heavy atom effect.
Zero‐dimensional Ph4P+ (TPP+) metal halide hybrids have been developed to exhibit distinct photophysical properties, from highly efficient phosphorescence to ultralong afterglow. The afterglow properties of Ph4P+ cations could be suspended for the hybrids containing low band gap emissive metal halide species, such as SbCl52− and MnCl42−, but enhanced for the hybrid containing wide band gap non‐emissive ZnCl42−.
Pancreatic cancer is one of the most lethal malignancies worldwide. Although the standard of care in pancreatic cancer has improved, prognoses for patients remain poor with a 5-year survival rate of ...< 5%. Angiogenesis, namely, the formation of new blood vessels from pre-existing vessels, is an important event in tumor growth and hematogenous metastasis. It is a dynamic and complex process involving multiple mechanisms and is regulated by various molecules. Inhibition of angiogenesis has been an established therapeutic strategy for many solid tumors. However, clinical outcomes are far from satisfying for pancreatic cancer patients receiving anti-angiogenic therapies. In this review, we summarize the current status of angiogenesis in pancreatic cancer research and explore the reasons for the poor efficacy of anti-angiogenic therapies, aiming to identify some potential therapeutic targets that may enhance the effectiveness of anti-angiogenic treatments.
In this paper, a method for designing substrate integrated waveguide (SIW) filtering rat-race couplers based on TE 102 and TE 201 orthogonal degenerate modes is proposed for the first time. Without ...additional circuits, the desired 0° and 180° phase differences of the rat-race coupler are realized by the inherent in-phase and out-of-phase characteristics of E-fields at TE 102 and TE 201 modes. E-field distributions of the SIW cavities at TE 102 and TE 201 modes are studied for guiding the circuit realization. By properly arranging the locations of input-output ports and coupling regions in the SIW cavities, magnitude and phase properties of the rat-race coupler topology are realized. And then the filtering responses can be integrated with the rat-race coupler. A detailed design method based on coupling matrix is presented. A filtering rat-race coupler is implemented using square SIW cavities to verify the proposed method, showing good performance of filtering responses, amplitude balance, as well as 0° and 180° phase differences. For further verification, another filtering rat-race coupler is fabricated using two circular SIW cavities to simplify the structure. Comparison with other filtering couplers indicates that the proposed designs exhibit the advantages of good filtering responses, relatively high Q factor of the entire filtering circuits, and simple structure.
As low‐dimensional lead‐free hybrids with higher stability and lower toxicity than those of three‐dimensional lead perovskites, organic antimony(III) halides show great application potential in ...opt‐electronic field owing to diverse topologies along with exceptional optical properties. We report herein an antimony(III) hybrid (MePPh3)2SbCl5 with a zero‐dimensional (0D) structure, which exhibits brilliant orange emission peaked at 593 nm with near‐unity photoluminescent quantum yield (99.4 %). The characterization of photophysical properties demonstrates that the broadband emission with a microsecond lifetime (3.24 μs) arises from self‐trapped emission (STE). Electrically driven organic light‐emitting diodes (OLEDs) based on neat and doped films of (MePPh3)2SbCl5 were fabricated. The doped devices show significant improvement in comparison to non‐doped OLEDs. Owing to the much improved surface morphology and balanced carrier transport in light‐emitting layers of doped devices, the peak luminance, current efficiency (CE) and external quantum efficiency (EQE) are boosted from 82 cd m−2 to 3500 cd m−2, 1.1 cd A−1 to 6.8 cd A−1, and 0.7 % to 3.1 % relative to non‐doped devices, respectively.
A highly luminescent organic antimony(III) hybrid (MePPh3)2SbCl5 featured with STE emission is prepared with good reproducibility and high stability. High‐efficiency OLEDs are demonstrated with this hybrid as an emitter with the luminance of 3500 cd m−2, current efficiency of 6.8 cd A−1 and EQE of 3.1 %, respectively.
In this article, a four-way low-loss reconfigurable power divider with arbitrary operating channels is designed with a simple circuit configuration. A reconfigurable transmission line (RTL) is ...proposed, which can be switched between two different characteristic impedances with constant electric length. When setting the constant electric length as 90°, the RTLs are used as switchable <inline-formula> <tex-math notation="LaTeX">K </tex-math></inline-formula> inverters to construct a four-way reconfigurable power divider. Then, by controlling the switchable <inline-formula> <tex-math notation="LaTeX">K </tex-math></inline-formula> inverters, the power divider can be fully reconfigured in one-channel (State 1), two-channel (State 2), three-channel (State 3), four-channel (State 4), and all-channel-OFF (State 5) operations. Without using extra impedance matching networks, good port matching is achieved in the states with arbitrary transmission channels. Thus, this simple circuit configuration can be applied in the feeding network of antenna systems to achieve flexibly reconfigurable coverages. For verification, a circuit is designed and fabricated. Good agreement between the simulated and measured results is observed. In comparison with reported multiway reconfigurable power dividers, the proposed one exhibits low insertion loss, wide bandwidth, and simple structure.
This article presents a scheme for designing single-to-balanced and balanced-to-balanced dual-channel filters using multilayer substrate integrated waveguide (SIW) cavities. By sharing the common SIW ...cavities, two single-to-balanced or two balanced-to-balanced filters are flexibly integrated as one dual-channel circuit, resulting in very high integration. The input and output ports are properly arranged to the SIW cavities, where the two modes of the TM 110 degenerate modes can be separately excited by the ports of the two filter channels. Moreover, the resonance modes of one channel have no coupling to those of the other channel. Thus, isolation between the two channels is achieved even though the two channels are designed sharing the same SIW cavities. The desired balanced ports are achieved based on the inherent out-of-phase electric field property of the SIW cavity at TM 110 degenerate modes. For verification, a six-port single-to-balanced dual-channel filter is implemented, exhibiting excellent single-to-balanced filtering responses of each channel and high isolation between the two channels. By converting the single-ended ports to balanced ports, second-order and third-order balanced-to-balanced dual-channel filters are proposed. Moreover, the proposed designs can also realize different channel bandwidth or channel frequencies to meet different wireless applications.
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