Electromagnetically induced transparency (EIT) and electromagnetically induced absorption (EIA) have many applications, especially for achieving slow light and fast light. EIT and EIA have been widely observed in both quantum and classical systems where two transition pathways could interference destructively or constructively. Multipathway interference has been a concern in recent works, however, due to the difficulty of precisely controlling the system parameters, the experimental study of multipathway interference is generally challenging. In this paper, we explore a coupled high-temperature-superconducting (HTS) resonator platform for implementing three-pathway electromagnetically induced transparency (TEIT) and absorption (TEIA). In our system, both resonant frequencies and linewidths (loss) of each resonator as well as their coupling strength can be precisely controlled, thus TEIT and TEIA can be implemented as a set. Our proposed method shows great potential for use in microwave signal processing in the future, such as slow wave, fast wave, and radio-frequency memory. Our results indicate the HTS resonator is an ideal platform for investigating versatile coherent phenomena.

Different from additive manufacturing and subtractive manufacturing, iso-material manufacturing (also named isovolumetric manufacturing) is applied to 304 stainless steel (304SS) by laser surface melting (LSM) at four energy density (51 J/mm2, 44 J/mm2, 39 J/mm2, 37 J/mm2), aiming at improving the resistance to corrosion and cavitation erosion without any addition of precious metals. The experimental results show that the microstructure presents the transformation from plane crystal → columnar crystal → equiaxed crystal from interface to top surface. All the samples exhibit austenite+martensite+Cr23C6, and the martensite content is increased from 9.3% to 40.8% with the energy density decreasing after iso-material manufacturing. In addition, low angle grain boundary is increased, and nano-mechanical properties also show an increasing trend. The decreasing of energy density also enhances the residual tensile stress of the melting layer. The sample obtained at energy density of 51 J/mm2 displays the highest corrosion resistance in 3.5 wt% NaCl solution, which can be attributed to its low galvanic corrosion degree and small residual tensile stress. The sample obtained at energy density of 39 J/mm2 exhibits the highest cavitation erosion resistance (Re) and its passivation film displays better self-repairing and re-passivation ability as indicated by synergistic cavitation erosion-corrosion behavior. The high cavitation erosion resistance can be attributed to the proper compromise of the constituent phases and higher self-repairing of the passivation film for the melting layer. Moreover, the 304 stainless steel prepared in this study exhibits a high or comparable corrosion and cavitation erosion resistance in comparison with the samples prepared by other fabrication method reported previously.

Storing a very high frequency (VHF) band (30 – 300 MHz) electromagnetic wave has many potential applications, such as phase modulation, buffering, and radio frequency memory. It can be effectively achieved by applying coupled resonator-based electromagnetically induced transparency (EIT) due to its slow light effect. However, the wavelength in the VHF band is too long to design resonators, and the group delay is limited by the high resistive loss of metal. The practical application of EIT in the VHF band is still a big challenge. In this work, we propose and experimentally demonstrate EIT response in a high-temperature superconducting (HTS) microwave circuit with coupled-resonator-induced transparency. The chip size of the HTS circuit is only 34 mm × 20 mm with a very low transparency frequency of 198.55 MHz. In addition, we implement very large group delay higher than 12.3 μ s and 16.2 μ s with working temperatures of 65 K and 50 K separately, which is much longer than the previous reported works on slow wave. The fabricated circuit is planar with working temperature about 65 K, and thus can be easily integrated into other microwave devices under the cryogenic conditions provided by a commercial portable Stirling cryocooler. Our proposed method paves a way for studying EIT in the microwave region due to the high quality factor of the HTS resonator, which has great potential use for radio-frequency memory in the future.

A novel dual-mode optimized patch capacitor loaded T-type resonator is proposed for the design of a dual-band filter (DBF). The resonator has its lowest even- and odd-mode at the two expected passband frequencies and the first spurious mode far away from the passbands. For tuning of the two sets of coupling strengths for both passbands, open/shorted secondary coupling structures are introduced as a fine-tuning coupling structure to increase/decrease the primary coupling strength. A four-pole DBF with passbands centered at 2450 and 3500 MHz, respectively, is proposed and fabricated using the HTS material. The measured results of the filter indicate superior performance and good fitting with the simulation results. The return losses of both passbands and the insertion losses obtained by measurements are greater than 14 dB and less than 0.3 dB, respectively. The stopband rejection exceeds 50 dB up to 8.0 GHz.

In this study, we propose a stepped-impedance-stub loaded interdigital capacitor resonator for design of a dual-band band-pass filter with a large bandwidth ratio. The presented resonator has strong and weak couplings in the upper passbands (UPs) and lower passbands (LPs), respectively, so as to form a large upper/lower bandwidth ratio. Adopting a dual-branch phase-matched feedline structure can meet the external quality factors required for the UP/LP. Therefore, these two passbands, defined by their respective center frequencies and bandwidths, can be manipulated independently. A four-pole dual-band example filter with a lower bandwidth of 20 MHz at 1576 MHz and an upper bandwidth of 200 MHz at 2450 MHz is successfully designed on an YBCO/MgO superconducting wafer. The filter exhibits excellent frequency responses. The upper/LPs show insertion losses below 0.07/0.22 dB and return losses above 15.3/15.3 dB. The stopband rejection is better than 57 dB until the first spurious passband up to 6150 MHz (3.9fL).

A novel N-spiral resonator with open-loop secondary coupling structure (OLSCS) is proposed to realize a compactultra-narrowband high temperature superconducting (HTS) filter. The coupling strength and polarity between the resonators can be significantly reduced and changed by introducing OLSCS, thus the required weak coupling can be achieved in a very compact size. A six-pole superconducting filter at 1701 MHz with a fractional bandwidth of 0.19％is designed to validate this method. The filter is fabricated on MgO substrate with a compact size of 15 mm × 10 mm. The measured insertion loss is 0.79 dB, and the return loss is better than 17.4 dB. The experimental results show a good agreement with the simulations.

A wideband wide stopband filter is designed using asymmetric stepped-impedance resonators (ASIRs) connected to a large open stub. The capacitive open stub and the parallel-coupled microstrip line are used to achieve the strong couplings for large fractional bandwidth (FBW). For a wide-stopband performance, the proposed filter uses ASIRs to improve the high-order spurious resonant frequency. The first and last resonators of the proposed filter are further optimized to suppress the spurious resonant frequency caused by open stub. The final filter has a 70% FBW centered at 4.87 GHz with 20-dB-rejection stopband up to 15.78 GHz (approximately 3.24f(0)). The measured insertion loss is less than 0.15 dB and the return loss is better than 17 dB.

The invention discloses a low-temperature microwave filtering system based on electromagnetic coupling of adiabatic space, The invention can effectively solve the problem that the conductive heat leakage of the low-temperature microwave filter module is large due to the direct connection of the input and output cables, and the conductive heat leakage of the low-temperature microwave filter moduleis reduced by the way of electromagnetic coupling in the adiabatic space, so that the whole temperature of the low-temperature microwave filter module is uniform and stable, and the performance of thelow-temperature microwave filter module is more stable and excellent; (cable with more excellent performance, i. E., coarser and short than previously available, enable that overall volume of the microwave electronic system to be reduced, the performance to be better, the power to be great, and the miniaturization of the microwave electronic system to be facilitated; On the premise of installingthe same number of cryogenic filter modules, the power consumption of the refrigeration platform is greatly reduced, and the volume and manufacturing cost of the superconducting electronic system aregreatly reduced. It makes possible the realization of some multi-channel superconducting electronic systems which can not be manufactured due to the limitation of cryogenic platforms.

Background: Adults with acute myeloid leukemia with normal cytogenetics (AML-CN) have variable relapse risks. New mutations correlated with relapse risk are needed. Understanding clonal trajectory of relapse in this setting may improve understanding of leukaemia development. Aims: Interrogate genomic landscape and clone trajectory data in adults with CN-AML and identify new mutations associated with relapse risk. Methods: 333 consecutive, newly-diagnosed adults with CN-AML seen in Peking University Peoples Hospital March, 2006 and April, 2018 were studied. Whole-exome sequencing (WES) was done in 23 subjects with diagnosis, remission and relapse samples. Using these and published data we developed a customized panel of 322 AML-related genes. Diagnostic DNA samples of the remaining 310 subjects were studied and the coding regions or hotspot areas of the 322 genes were sequenced by deep target regional sequencing (TRS). Average effective sequencing depths were 200X (145–265X) for WES and 1500X (1000–1800X) for TRS. Median coverages were 99.9% (77.6, 99.9%) and 99.0% (98.0, 99.5%). Results: We identified 3672 non-synonymous somatic variants in 309 genes by TRS. In 305 subjects ≥5 mutations were identified (98%; 95% confidence interval [CI], 97, 100%), with a median of 13 mutations per subject (range, 2–27; Figure). We identified mutations at 4 new loci including DDX11 in 23 subjects (7%), CYP2F1(4%), NPIPA5 (3%) and MED12 (2%). We then interrogated the impact of DDX11 mutations by matching these subjects with 115 controls according to age (<60/≥60 y), NPM1(Y/N) and FLT3-ITD(Y/N) mutations and WBC (<100/≥100x10E+9/L). In multivariable analyses DDX11 mutation was independently-associated with cumulative incidence of relapse (CIR; Hazard Ratio [HR] = 2.15 [1.12, 4.13]; P = 0.021) and relapse-free survival (RFS; HR = 2.12 [1.03, 4.38];P = 0.042). Other mutations identified included driver genes in the RAS/RTK signaling pathway (27%), chromatin modifier pathway(10%), DNA-methylation pathway (8%), transcription factor pathway (8%), histone methylation pathway (5%), cohesin complex pathway (3%) and the spliceosome pathway (3%). NPM1 was the most frequent mutated gene in our cohort (N = 75; 24% [19, 29%]), followed by FLT3-ITD (N = 64; 21% [16, 25%]) and DNMT3A (N = 59; 19% [15, 23%]). Using triplicate samples from the 23 subjects we identified 3 clonal trajectory patterns: (1) Dominant clone at diagnosis and relapse without new mutations (N = 2); (2) Dominant clone at diagnosis with ≥1 new mutation (N = 13); and (3) evolution from a minor clone detected at diagnosis (N = 8).The clonal trajectory of relapse after chemotherapy was like that posttransplant but the latter was associated with more relapse-specific sub-clones possibly related to intensive pretransplant conditioning.Summary/Conclusion: We identified 4 new mutated genes in AML-CN and show DDX11 mutations correlate with a higher CIR and worse RFS in multivariable analyses. We also detected 3 distinct clonal trajectories which provide insight into mechanisms of relapse after chemotherapy and transplantation and the pathogenesis of AML-CN.

This paper analyzes the asymmetrical split phenomenon of the odd and even modes in microstrip for closely coupled resonators. In general, when two resonators are coupled, the odd- and even-mode split is asymmetrical. This paper finds that, for two closely coupled resonators, odd mode always changes faster than even mode. This asymmetrical phenomenon is first predicted by using the effective capacitances of the even and odd mode. Then, the electric, magnetic, and mixed couplings are all discussed to demonstrate this phenomenon. Numerical results help us to control the odd mode in a wide range. This paper presents an ultra-wideband filter by using the interdigital coupled structure for the first time. A high-temperature superconducting filter operating at 7 GHz with -3 dB FBWs of 103% is designed and fabricated. Measured results show good performance and agree well with the simulations.

提出了一种具有可重构带阻特性的超宽带超导滤波器,可有效抑制通带内的干扰信号.该超宽带滤波器基本结构是由改进后的多模谐振器和平行耦合微带馈线构成.2-bit叉指电容(interdigital capacitor,IDC)阵列被加载在平行耦合馈线外端,实现阻带的“开/关”及阻带中心频率的控制.该滤波器是在尺寸为20.0mm×6.0mm的MgO介质基片上实现的.未经调谐的测试结果显示了优异特性,并且和仿真结果吻合得很好.超宽带通带内的阻带可自由“开/关”,中心频率调节范围从7.15到7.49GHz.此外,阻带在所有“开”的状态下显示了高的选择性(10dB带宽小于3％)和高的抑制性(高于38dB).

A stepped-impedance resonator with an interdigital capacitor (IDC) structure has been proposed to design a wideband filter with a wide and deep stopband. With the increase of the IDC part, there is always a maximum ratio of a spurious resonance frequency to a fundamental resonance frequency whether we change the length or number of interdigital fingers. We increase the width of a microstrip line loaded with the IDC structure to reduce the fundamental resonance frequency and increase the spurious resonance frequency. The harmonic ratio of the proposed resonator is raised to 5.6. Moreover, we bend the narrow microstrip line into a meander line to realize the strong coupling for a wideband filter. A ten-pole high-temperature superconducting filter centered at 2.128 GHz with a 22.7% bandwidth is fabricated for demonstration. The filter is fabricated on a 0.5-mm-thick MgO substrate with a circuit size of 26 x 10 mm. The measured maximum insertion loss in passband is 0.11 dB and the return loss is better than 17.3 dB. The measured out-of-band rejection is better than 80 dB up to 8.728 GHz, which is about 4.1 times of the center frequency.

A twin spiral-in-spiral-out (SISO) resonator has been proposed in the design of a compact ultra-narrows band high temperature superconducting filter. We systematically investigated the relationship between the coupling characteristics and the structure of the twin SISO resonator. Coupling strength and polarity can be effectively changed by adjusting the resonator structural ratio. This method of optimizing the ratio of the twin SISO resonator structure has an advantage of achieving stable and weak coupling, even if the resonator distance is relatively narrow, thereby promoting the miniaturization of the filter. Moreover, the three methods of optimizing ratio, distance, and staggering of adjacent resonators could be regarded as three degrees of freedom for adjusting the adjacent coupling to meet design needs. To demonstrate this method, we designed and fabricated a six-order superconducting filter with a fractional bandwidth of 0.18% at 2258 MHz based on the optimized twin SISO resonator. The resulting measurement shows a good agreement with the simulation.

A high-temperature superconducting wideband bandpass filter based on a triple-mode resonator is developed in this letter. A novel triple-mode resonator, which can not only generate a wide passband at low frequency but also suppress the harmonic responses and obtain a wide stopband, is proposed. To further improve the selectivity, we load two stubs at the input and output ports to generate one transmission zero at the low passband. The simulation results show that the filter is centered at 1 GHz (f(c)) with 111% 3-dB fractional bandwidth and has an upper stopband to 3.5f(c). The measured results show that the return loss is larger than 15 dB, and the insertion loss is less than 0.26 dB.

This paper presents a new type superconducting diplexer designed with double-side structure. The two channels of the diplexer are located on the different layers of the superconducting thin films. One channel consists of four-pole microstrip stepped impedance resonators(MSIR) on the upper side, while the other channel consists of four-pole slotline stepped impedance resonators(SSIR) on the back side. In this paper, the coupling of MSIR-SSIR and MSIR-MSIR is compared, and the simulated results show that the latter is weaker than the former in a certain distance. High isolation between the two channels is therefore achieved because of their highly suppressed unwanted cross-coupling. The diplexer is fabricated on a MgO substrate with a double-side-coated 500-nm-thick YBCO HTS thin films and exhibits high performance. The measurements agree well with the simulations, and the isolation is over 45dB.

The invention discloses a microstrip resonator based on a buried interdigital structure and a microstrip filter. An open end of an original resonator is connected with the buried interdigital structure through a microstrip line, then an interdigital structure can be formed with the ground, so that the interdigital structure can be loaded to various resonator structures and can be applied to quarter-wavelength structures to which the traditional interdigital structure cannot be loaded, and higher impedance ratio can be obtained. The interdigital structure is wholly buried in the ground structure, so that the influence of the interdigital structure on coupling of resonators is quite small, and bandwidth selection range of a wide suppression filter designed on the basis of the structure is larger.

The invention discloses a dual-passband filter formed by coupling path separating dual-mode resonators and an optimization method. An interstage coupling coefficient of a first resonance mode is onlycontrolled by half-wavelength resonators; a resonant electric length in a second resonance mode comprises symmetric half-wavelength resonators and loading branch lines; when two dual-mode resonators are coupled at a certain distance, the loading branch line of one resonator is coupled to that of the other resonator and the loading branch lines and the half-wavelength resonators control the interstage coupling coefficient of a second resonance mode at the same time, so that the design freedom of the interstage coupling coefficients of the two dual-mode resonators is increased and the coupling coefficients between the two resonance modes can be independently designed; and furthermore, the included electric lengths in the two resonance modes are different, so that external coupling coefficients which are required for the two resonance modes separately when the first dual-mode resonator is coupled to an external feeder can also be independently controlled.

In this paper, an interdigital-type resonator with strong electric coupling is proposed for the wideband high-frequency (> 10 GHz) filter design. The proposed microstrip resonator consists of an H-shaped main line part with its both ends installed with interdigital finger parts. Strong electric coupling is achieved between adjacent resonators. A six-pole high-temperature superconducting filter at Ku-band using this resonator is designed and fabricated. The filter has a center frequency of 15.11 GHz with a fractional bandwidth of 30%. The insertion loss of the passband is less than 0.3 dB, and the return loss is greater than 14 dB without any tuning. (c) 2017 Elsevier B.V. All rights reserved.

A stepped-impedance-stub loaded stepped-impedance resonator (SISLSIR) is proposed to design a dual-band bandpass filter. The even- and odd-mode frequencies and the coupling strength of the proposed resonators can be independently designed and adjusted. A dual-feedline structure is used to meet the required external couplings of the 2 passbands. Thus, both the center frequencies and the bandwidths of the 2 passbands can be independently controlled. A 6-pole dual-band filter with the passbands of 3300 approximate to 3600 MHz and 4800 approximate to 5000 MHz is successfully designed using the proposed method and fabricated with YBCO/MgO high-temperature superconducting (HTS) wafer. The measured results of the filter exhibit high performance and match well with the simulations. The measured insertion losses are less than 0.2/0.3 dB, and the return losses are greater than 15/14 dB for the lower/upper passbands, respectively. The out-of-band rejection is greater than 68 dB up to 12 GHz.

This paper proposes a new coupling matrix synthesis technique called the coupling matrix compression technique, which focuses on reducing the dimension of the $N+2$ coupling matrix. The presented coupling matrices can be compressed, and this technique can be used to design dual-mode resonators for high-isolation dual-band filters. One dual-mode resonator is represented as two closely coupled resonators when using this technique. The formulae for resonant frequencies and $\omega _{m}$ in dual-mode theory are also derived in this paper. A dual-mode embedded hairpin resonator is designed and analyzed using this technique, and a dual-band filter using the proposed resonators is designed and fabricated to validate the proposed technique.