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13 pages, 1733 KB  
Article
Genotype Frequency of HLA-B*58:01 and Its Association with Paraclinical Characteristics and PSORS1C1 rs9263726 in Gout Patients
by Hien Thu Nguyen, Ha Thi Bui, Yen Thi Thu Hoang, My Ha Hoang, Manh Duc Ngo, Mai Hoang Nguyen, Thuy Thi Thanh Nguyen, Nhuan Tien Ngo and Quang Viet Nguyen
Diagnostics 2025, 15(16), 2114; https://doi.org/10.3390/diagnostics15162114 - 21 Aug 2025
Viewed by 618
Abstract
Background/Objectives: The HLA-B*58:01 allele is strongly linked to severe cutaneous adverse reactions (SCARs) during allopurinol treatment, and it has been associated with the A allele of PSORS1C1 rs9263726 (G>A). Paraclinical characteristics of gout are indicative of associated comorbid conditions. This study investigated [...] Read more.
Background/Objectives: The HLA-B*58:01 allele is strongly linked to severe cutaneous adverse reactions (SCARs) during allopurinol treatment, and it has been associated with the A allele of PSORS1C1 rs9263726 (G>A). Paraclinical characteristics of gout are indicative of associated comorbid conditions. This study investigated the genotype frequency of HLA-B*58:01 and its association with paraclinical characteristics and PSORS1C1 rs9263726 in gout patients from Northeast Vietnam. Methods: A total of 133 unrelated gout patients were randomly recruited by the clinician. BioEdit sequence alignment editor version 7.2.5 software (Raleigh, Raleigh, NC, USA) was used for the analysis of nucleotide sequence data of HLA-B gene alleles from the IPD-IMGT/HLA Database, which showed that the HLA-B*58:01 allele can be distinguished from reference and other alleles by specific nucleotide positions: 387C, 379C, 368A, 355A, and 353T (in exon 3); and 319C, 285G, and 209A (in exon 2). HLA-B*58:01 and PSORS1C1 rs9263726 genotypes were identified using Sanger sequencing of PCR products, analyzed with BioEdit software, and verified using the NCBI dbVar database. Statistical analyses were performed using SPSS version 25.0. Results: Our study revealed a significant age difference between male and female gout patients (p < 0.001). Male gout patients had an average age of 51.44 ± 14.59 years, whereas female gout patients were notably older, with an average age of 70.33 ± 10.64 years. Positive correlations were observed between platelet count, serum creatinine, and uric acid levels (r = 0.174, p = 0.045; r = 0.195, p = 0.025) in male gout patients, while only high-density lipoprotein cholesterol showed a statistically significant negative correlation with uric acid levels (r = −0.885, p = 0.002) in female patients. The HLA-B*58:01 allele frequency among study subjects was 6.02%, with 12.03% being heterozygous individuals (*X/HLA-B*58:01, N = 16). The HLA-B*58:01 allele was not detected in female gout patients. White blood cell counts were significantly higher in male gout patients with the *X/HLA-B*58:01 genotype compared to those with the *X/*X genotype (p = 0.018). The A allele frequency of PSORS1C1 rs9263726 was 7.89%, and the heterozygous mutant genotype PSORS1C1 GA had a frequency of 15.79% (N = 21). Among the *X/*58:01 carriers, 4.51% had the GG genotype, and 7.52% had the GA genotype at PSORS1C1 rs9263726. Conclusions: Our study showed that the HLA-B*58:01 allele was not detected in female gout patients. White blood cell counts differed significantly between the *X/HLA-B*58:01 and *X/*X groups in male gout patients. The A allele of PSORS1C1 rs9263726 was not consistently associated with HLA-B*58:01 and was not a reliable marker for its detection in this study population. Full article
(This article belongs to the Section Pathology and Molecular Diagnostics)
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2 pages, 133 KB  
Abstract
Genomic Surveillance of Streptococcus pneumoniae and Streptococcus pyogenes in the Czech Republic in the Post-COVID-19 Era
by Sandra Vohrnová, Renáta Veselá and Jana Kozáková
Proceedings 2025, 124(1), 20; https://doi.org/10.3390/proceedings2025124020 - 18 Aug 2025
Viewed by 536
Abstract
Aim: The aim of this study is to assess the impact of COVID-19 on the incidence and molecular epidemiology of invasive infections caused by Streptococcus pneumoniae (IPD) and Streptococcus pyogenes (iGAS) in the Czech Republic (CR) [...] Full article
10 pages, 6226 KB  
Article
8-W 2-Stage GaN Doherty Power Amplifier Module on 7 × 7 QFN for the 5G N78 Band
by Sooncheol Bae, Kuhyeon Kwon, Hyeongjin Jeon, Young Chan Choi, Soohyun Bin, Kyungdong Bae, Hyunuk Kang, Woojin Choi, Youngyun Woo and Youngoo Yang
Electronics 2025, 14(12), 2398; https://doi.org/10.3390/electronics14122398 - 12 Jun 2025
Viewed by 675
Abstract
This paper presents a 2-stage GaN Doherty power amplifier module (DPAM) on a compact 7×7 quad flat no-lead (QFN) package, designed for the needs of 5G massive MIMO base transceiver systems. The interstage and input matching networks employ high-quality factor integrated [...] Read more.
This paper presents a 2-stage GaN Doherty power amplifier module (DPAM) on a compact 7×7 quad flat no-lead (QFN) package, designed for the needs of 5G massive MIMO base transceiver systems. The interstage and input matching networks employ high-quality factor integrated passive devices (IPDs) to achieve a small form factor. This multi-chip module consists of three GaN-HEMT bare dies used for the driver stage, carrier amplifier, and peaking amplifier. Additionally, two IPD dies are included for the interstage and input matching networks. The external load network is developed using a printed circuit board (PCB). Utilizing a 5G NR signal of 100 MHz bandwidth and a 9.3 dB PAPR within the 3.4–3.8 GHz band, the developed DPAM demonstrated a power gain exceeding 26.8 dB and a power-added efficiency (PAE) greater than 37.8% at a 39 dBm average output power. Full article
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11 pages, 569 KB  
Article
Olfactory Perception in Parkinson’s Disease: The Impact of GBA1 Variants (Sidransky Syndrome)
by Mikhal E. Cohen, Yosef Shechter, Melania Dominko, Elena Shulman, Tama Dinur, Shoshana Revel-Vilk, Roni Eichel, Gilad Yahalom and Michal Becker-Cohen
Int. J. Mol. Sci. 2025, 26(11), 5258; https://doi.org/10.3390/ijms26115258 - 30 May 2025
Viewed by 703
Abstract
Parkinson’s disease (PD) associated with GBA1 mutations—recently termed Sidransky syndrome—differs from idiopathic PD (iPD) by earlier onset, more rapid progression, and higher rates of non-motor symptoms. Our objective was to assess whether GBA1 mutations contribute to olfactory dysfunction in PD and in asymptomatic [...] Read more.
Parkinson’s disease (PD) associated with GBA1 mutations—recently termed Sidransky syndrome—differs from idiopathic PD (iPD) by earlier onset, more rapid progression, and higher rates of non-motor symptoms. Our objective was to assess whether GBA1 mutations contribute to olfactory dysfunction in PD and in asymptomatic carriers of the mutation. We compared olfactory and motor functions in 119 participants: Sidransky syndrome (n = 18), iPD (n = 30), GBA1 variant carriers without PD (n = 21), Gaucher disease patients (n = 20), and healthy controls (n = 30). All were evaluated with the Brief Smell Identification Test (BSIT®) and the motor part of the Movement Disorders Society Unified PD Rating Scale (MDS-mUPDRS). Mean age was 59.2 ± 11.7 years. Mean disease duration was 2.5 ± 2.2 years in Sidransky syndrome and 5.4 ± 4.9 years in iPD. We found that both PD groups had significantly lower BSIT® scores than non-PD groups (p < 0.001), particularly for leather, smoke, natural gas, pineapple, clove, rose, and lemon. Sidransky syndrome patients scored lower than iPD patients (p = 0.04). No significant olfactory deficits were observed in GBA1 carriers or Gaucher patients without PD. We conclude that hyposmia is more pronounced in Sidransky syndrome than in iPD. However, normal olfaction in non-parkinsonian GBA1 carriers suggests that GBA1 variants alone do not account for olfactory loss in PD. Hyposmia likely reflects broader PD pathology rather than a direct effect of the GBA1 mutation. Full article
(This article belongs to the Special Issue Molecular Mechanisms of Genetic Variants of Parkinson’s Disease)
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15 pages, 2370 KB  
Article
Design and Optimization of a Fan-Out Wafer-Level Packaging- Based Integrated Passive Device Structure for FMCW Radar Applications
by Jiajie Yang, Lixin Xu and Ke Yang
Micromachines 2024, 15(11), 1311; https://doi.org/10.3390/mi15111311 - 29 Oct 2024
Cited by 2 | Viewed by 1731
Abstract
This paper presents an integrated passive device (IPD) structure based on fan-out wafer-level packaging (FOWLP) for the front end of frequency-modulated continuous wave (FMCW) radar systems, focusing on enhancing the integration efficiency and performance of large passive components like antennas. Additionally, a new [...] Read more.
This paper presents an integrated passive device (IPD) structure based on fan-out wafer-level packaging (FOWLP) for the front end of frequency-modulated continuous wave (FMCW) radar systems, focusing on enhancing the integration efficiency and performance of large passive components like antennas. Additionally, a new metric is introduced to assess this structure’s effect on the average noise figure in FMCW systems. Using this metric as a loss function, we apply the support vector machine (SVM) for electromagnetic simulation and the genetic algorithm (GA) for optimization. The sample fitting variance is 2.42 dB, reducing computation time from 12 min to under 1 millisecond, with the entire optimization completed in less than 100 s. The optimized IPD structure is 0.7 × 0.9 × 0.014 λ03 in size and achieves over 35 dB isolation between the transmitter and receiver. Compared to the IPD model calculated by empirical formulas, the optimized device lowers the average noise figure by 15.2 dB and increases maximum gain by 4.19 dB. Full article
(This article belongs to the Special Issue Advanced Packaging for Microsystem Applications, 3rd Edition)
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14 pages, 7513 KB  
Article
A Multilayered GaAs IPD Resonator with Five Airbridges for Sensor System Application
by Xiao-Yu Zhang, Zhi-Ji Wang, Jian Chen, Eun-Seong Kim, Nam-Young Kim and Jong-Chul Lee
Micromachines 2024, 15(3), 367; https://doi.org/10.3390/mi15030367 - 8 Mar 2024
Viewed by 2070
Abstract
This work proposes a microwave resonator built from gallium arsenide using integrated passive device (IPD) technology. It consists of a three-layered interlaced spiral structure with airbridges and inner interdigital structures. For integrated systems, IPD technology demonstrated outstanding performance, robustness, and a tiny size [...] Read more.
This work proposes a microwave resonator built from gallium arsenide using integrated passive device (IPD) technology. It consists of a three-layered interlaced spiral structure with airbridges and inner interdigital structures. For integrated systems, IPD technology demonstrated outstanding performance, robustness, and a tiny size at a low cost. The airbridges were made more compact, with overall dimensions of 1590 × 800 µm2 (0.038 × 0.019 λg2). The designed microwave resonator operated at 1.99 GHz with a return loss of 39 dB, an insertion loss of 0.07 dB, and a quality factor of 1.15. Additionally, an experiment was conducted on the properties of the airbridge and how they affected resistance, inductance, and S-parameters in the construction of the resonator. To investigate the impact of airbridges on the structure, E- and H-field distributions of the resonator were simulated. Furthermore, its use in sensing applications was explored. Various concentrations of glucose solutions were used in the experiment. The proposed device featured a minimum detectable concentration of 0.2 mg/mL; high sensitivity, namely, 14.58 MHz/mg·mL−1, with a linear response; and a short response time. Thus, this work proposes a structure that exhibits potential in integrated systems and real-time sensing systems with high sensitivity. Full article
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10 pages, 2743 KB  
Communication
n77 Radio Frequency Power Amplifier Module for 5G New-Radio High-Power User Equipment Mobile Handset Applications
by Ji-Seon Paek
Electronics 2024, 13(5), 908; https://doi.org/10.3390/electronics13050908 - 27 Feb 2024
Cited by 1 | Viewed by 2763
Abstract
This paper presents a highly efficient 5G New-Radio (NR) RF power amplifier module (PAM). The n77 PAM consists of a high-voltage differential-topology 2 μm GaAs HBT power amplifier, a CMOS controller, a silicon-on-insulator (SOI) switch, an integrated passive device (IPD) bandpass filter, a [...] Read more.
This paper presents a highly efficient 5G New-Radio (NR) RF power amplifier module (PAM). The n77 PAM consists of a high-voltage differential-topology 2 μm GaAs HBT power amplifier, a CMOS controller, a silicon-on-insulator (SOI) switch, an integrated passive device (IPD) bandpass filter, a low-noise amplifier (LNA), and a bi-directional coupler. This PAM generates a saturation output power of 32.7 dBm including the loss of the SOI switch and output filter. The designed n77 PAM is tested with a commercial envelope tracker IC (ET-IC). The designed PAM with an ET-IC achieves an ACLR of −37 dBc at a 27 dBm output power with a DFT-s-OFDM QPSK 100 MHz NR signal and saves a dc power consumption of 950 mW compared to the APT mode. For the CP-OFDM 256QAM with the most stringent EVM requirements, it achieves an EVM of 1.22% at 23 dBm and saves 640 mW compared to the APT mode. Full article
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20 pages, 14090 KB  
Article
Enhanced Volts-per-Hertz Sensorless Starting of Permanent Magnet Motor with Heavy Loads in Long-Cable Subsea Applications
by Virendra Singh, Goutham Selvaraj and Kaushik Rajashekara
Energies 2024, 17(4), 957; https://doi.org/10.3390/en17040957 - 19 Feb 2024
Cited by 1 | Viewed by 2205
Abstract
Permanent magnet (PM) motors are gaining prominence in subsea applications such as drilling, pumping, and boosting for oil and natural gas extraction. These motors are gradually replacing traditional induction motors. However, starting and operating PM motors at low speeds under heavy loads poses [...] Read more.
Permanent magnet (PM) motors are gaining prominence in subsea applications such as drilling, pumping, and boosting for oil and natural gas extraction. These motors are gradually replacing traditional induction motors. However, starting and operating PM motors at low speeds under heavy loads poses significant challenges. This is because of unknown initial rotor positions and resistive voltage drops due to the presence of a sinewave filter, transformer, and long cable. An unknown rotor position may result in temporary reverse speed, which may cause a loss of synchronism; therefore, initial rotor position estimation is preferable. Additionally, addressing the voltage drop issue requires careful voltage compensation to avoid transformer core saturation. In this paper, an enhanced V/Hz starting of a PM motor is proposed with initial position detection (IPD) and voltage compensation to start the motor reliably with a heavy load. The proposed control method is verified with controller hardware in the loop (C-HIL) real-time simulation using a Typhoon HIL-604 emulator and a Texas Instruments TMS320F28335 digital signal processor (DSP) control card. Full article
(This article belongs to the Section F3: Power Electronics)
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15 pages, 8547 KB  
Article
High-Efficiency and Cost-Effective 10 W Broadband Continuous Class-J Mode Quasi-MMIC Power Amplifier Design Utilizing 0.25 μm GaN/SiC and GaAs IPD Technology for 5G NR n77 and n78 Bands
by Hwann-Kaeo Chiou, Hsin-Chieh Lin and Da-Chiang Chang
Electronics 2023, 12(16), 3494; https://doi.org/10.3390/electronics12163494 - 17 Aug 2023
Cited by 3 | Viewed by 2582
Abstract
This paper presents two power amplifiers designed for 5G NR n77 and n78 bands. These power amplifiers were fabricated using WINTM Semiconductors’ 0.25 μm GaN/SiC technology and GaAs IPD technology. To achieve a reduction in costs, GaAs IPD technology was incorporated in [...] Read more.
This paper presents two power amplifiers designed for 5G NR n77 and n78 bands. These power amplifiers were fabricated using WINTM Semiconductors’ 0.25 μm GaN/SiC technology and GaAs IPD technology. To achieve a reduction in costs, GaAs IPD technology was incorporated in the design, leading to the realization of a quasi-monolithic microwave integrated circuit design. To ensure high power, high efficiency, and broadband operation, a continuous Class-J mode output matching network was utilized. The power amplifier with split chip-on-board wire-bond assembly had a power gain of 21.7 dB, a 3 dB power bandwidth ranging from 2.85 GHz to 4.48 GHz, a saturation power of 40.3 dBm, and a peak power-added efficiency of 39.5%. On the other hand, the power amplifier with stack chip-on-board wire-bond assembly had a power gain of 21.7 dB, a 3 dB power bandwidth ranging from 2.84 GHz to 4.47 GHz, a saturation power of 40 dBm, and a peak power-added efficiency of 36.5%. For a 5G NR FR1 256-QAM 100-MHz bandwidth modulated signal with a frequency range of 3.3 GHz to 4.2 GHz, both the split and stack chip-on-board wire-bond assembly power amplifiers achieved average output powers of 29.6 dBm and 28.3 dBm, respectively. These output powers were measured under an error vector magnitude requirement of 3.5%. Full article
(This article belongs to the Special Issue Microwave/Millimeter-Wave Power Amplifiers)
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27 pages, 3814 KB  
Article
Volatile Profiles of Vidal Grapes in the Shangri-La High-Altitude Region during On-Vine Non-Destructive Dehydration
by Qing-Fang Xu, Liang Fan, Kai-Xiang Lu, Dong-Mei Zhao, Ming-Xia Zhang and Jian Cai
Horticulturae 2022, 8(11), 1029; https://doi.org/10.3390/horticulturae8111029 - 3 Nov 2022
Cited by 1 | Viewed by 2342
Abstract
Both free and glycosidically bound forms of volatile compounds in Vidal grapes from the Shangri-La high-altitude region during the on-vine non-destructive dehydration process were investigated by headspace solid-phase micro-extraction (HS-SPME) combined with gas chromatography–mass spectrometry (GC-MS), following which the data were processed by [...] Read more.
Both free and glycosidically bound forms of volatile compounds in Vidal grapes from the Shangri-La high-altitude region during the on-vine non-destructive dehydration process were investigated by headspace solid-phase micro-extraction (HS-SPME) combined with gas chromatography–mass spectrometry (GC-MS), following which the data were processed by multivariate statistical analysis. Fatty-acid-derived volatiles (FADs), amino-acid-derived volatiles (AADs), and isoprene-derived volatiles (IPDs), which occurred mainly in bound forms, were the three major volatiles in dehydrated Vidal grapes. Water-loss concentration, biosynthesis, and biodegradation all occurred during dehydration, eventually modifying some volatiles significantly, especially some powerful odorants such as hexanal, trans-2-hexenal, 2-phenethyl acetate, β-myrcene, linalool, geraniol, cis-rose oxide, and β-damascenone. 1-Octen-3-ol was relatively stable during the non-destructive on-vine dehydration process and its content in grape juice was mainly determined by the concentration effect. 2,4-Di-tert-butylphenol, 2-phenethyl acetate, 2-methyl-1-propanol, and hexanol were screened as some of the most important metabolic markers to discriminate grapes at different dehydration degrees. Our study also highlights the fundamental importance of the expression of volatile content in the metabolomic study of grape berries. Full article
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13 pages, 5753 KB  
Article
Design and Micro-Nano Fabrication of a GaAs-Based On-Chip Miniaturized Bandpass Filter with Intertwined Inductors and Circinate Capacitor Using Integrated Passive Device Technology
by Jian Chen, Bao-Hua Zhu, Shan Yang, Wei Yue, Dong-Min Lee, Eun-Seong Kim and Nam-Young Kim
Nanomaterials 2022, 12(3), 347; https://doi.org/10.3390/nano12030347 - 21 Jan 2022
Cited by 4 | Viewed by 3373
Abstract
In this study, we propose a miniaturized bandpass filter (BPF) developed by combining an approximate circular (36-gon) winding inductor, a circinate capacitor, and five air-bridge structures fabricated on a gallium arsenide (GaAs) substrate using an integrated passive device (IPD) technology. We introduced air-bridge [...] Read more.
In this study, we propose a miniaturized bandpass filter (BPF) developed by combining an approximate circular (36-gon) winding inductor, a circinate capacitor, and five air-bridge structures fabricated on a gallium arsenide (GaAs) substrate using an integrated passive device (IPD) technology. We introduced air-bridge structures into the outer metal wire to improve the capacitance per unit volume while utilizing a miniaturized chip with dimensions 1538 μm × 800 μm (0.029 λ0 × 0.015 λ0) for the BPF. The pattern was designed and optimized by simulating different dimensional parameters, and the group delay and current density are presented. The equivalent circuit was modeled to analysis various parasitic effect. Additionally, we described the GaAs-based micro-nano scale fabrication process to elucidate the proposed IPD technology and the physical structure of the BPF. Measurements were conducted with a center frequency of 1.53 GHz (insertion loss of 0.53 dB) and a 3-dB fractional bandwidth (FBW) of 70.59%. The transmission zero was located at 4.16 GHz with restraint of 35.86 dB. Owing to the benefits from its miniaturized chip size and high performance, the proposed GaAs-based IPD BPF was verified as an excellent device for various S-band applications, such as satellite communication, keyless vehicle locks, wireless headphones, and radar. Full article
(This article belongs to the Special Issue Transport and Noise Behavior of Nanoelectronic Devices)
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8 pages, 2004 KB  
Article
Compact, Reflectionless Band-Pass Filter: Based on GaAs IPD Process for Highly Reliable Communication
by Xiaozhen Li, Mengjiang Xing, Gan Liu, Xiaodong Yang, Chuanxiang Dai and Ming Hou
Electronics 2021, 10(23), 2998; https://doi.org/10.3390/electronics10232998 - 1 Dec 2021
Cited by 8 | Viewed by 3063
Abstract
For highly reliable and compact communication of front-end modules, a miniaturized reflectionless band-pass filter, based on the GaAs integrated passive device (IPD) process, is proposed in this work. The stop-band signal absorption rate of the filter can reach more than 90% and greatly [...] Read more.
For highly reliable and compact communication of front-end modules, a miniaturized reflectionless band-pass filter, based on the GaAs integrated passive device (IPD) process, is proposed in this work. The stop-band signal absorption rate of the filter can reach more than 90% and greatly reduce the influence of electromagnetic interference for sensitive devices. First, a circuit topology of reflectionless filter is proposed. Then, the miniaturized reflectionless band-pass filter is designed and fabricated based on GaAs IPD process with a compact size of only 0.85 mm × 1.33 mm × 0.09 mm (0.011λ × 0.018λ × 0.001λ). The filter operates at frequency ranging from 3.3 GHz to 4.5 GHz for 5G communication, the insertion loss (S21) is less than 3 dB, the return loss in the passband (S11) is over 15 dB, the stopband return loss (S11) is over 10 dB, and the out-of-band suppression (S21) reached 19 dB. All the measured results are in good agreement with the simulated results. It shows great potential in the process of designing highly reliable and compact monolithic integrated wireless modules and wearable electronics. Full article
(This article belongs to the Section Microwave and Wireless Communications)
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13 pages, 6443 KB  
Article
The Internal Residual Gas and Effective Release Energy of a Spark-Ignition Engine with Various Inlet Port–Bore Ratios and Full Load Condition
by Nguyen Xuan Khoa and Ocktaeck Lim
Energies 2021, 14(13), 3773; https://doi.org/10.3390/en14133773 - 23 Jun 2021
Cited by 8 | Viewed by 2091
Abstract
This paper presents the effect of inlet port diameter–bore ratios (IPD/B) on the effective release energy and internal exhaust residual gas of a spark-ignition engine. To investigate the exhaust residual gas in the combustion chamber, a simulation model is setup based on AVL-boost [...] Read more.
This paper presents the effect of inlet port diameter–bore ratios (IPD/B) on the effective release energy and internal exhaust residual gas of a spark-ignition engine. To investigate the exhaust residual gas in the combustion chamber, a simulation model is setup based on AVL-boost software, and to validate the simulation model an experimental model is also setup. The results of the research show that: the IPD/B ratios have a large effect on the residual gas and effective release energy. When the IPD/B ratio increases from 0.3–0.5, the residual gas increases from 0.11% to 0.14%, and the effective release energy increases from 0.33 KJ to a maximum value of 0.45 KJ, and after that decreases. The engine shows the maximum effective release energy at IPD/B ratio is 0.4. The emission of HC and CO is decreased, but the NOx is increased until a maximum value after that decreased. Full article
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9 pages, 3504 KB  
Article
A Compact Dual-Mode Bandpass Filter with High Out-of-Band Suppression Using a Stub-Loaded Resonator Based on the GaAs IPD Process
by Wei Zhang, Zhao Yao, Jie Zhang, Eun Seong Kim and Nam Young Kim
Electronics 2020, 9(5), 712; https://doi.org/10.3390/electronics9050712 - 26 Apr 2020
Cited by 2 | Viewed by 3747
Abstract
In this letter, a compact dual-mode bandpass filter (BPF) with an ultra-wide stopband that employs two folded open-loop resonators (FOLRs) and stub-loaded resonators (SLRs) is proposed. The dual-mode resonators are optimized by loading two SLRs onto the folded open-loop resonators, and this process [...] Read more.
In this letter, a compact dual-mode bandpass filter (BPF) with an ultra-wide stopband that employs two folded open-loop resonators (FOLRs) and stub-loaded resonators (SLRs) is proposed. The dual-mode resonators are optimized by loading two SLRs onto the folded open-loop resonators, and this process is analyzed using the dual-mode theory. To miniaturize the device size and increase chip performance, the proposed BPF is fabricated by a III–V compound semiconductor-fabrication process using a high-performance GaAs substrate based on the integration passivation device (IPD) fabrication process. A compact dual-mode BPF with low insertion loss and high return loss is designed and fabricated. Two extra transmission zeros (TZs) located in the high-frequency range increase the wide stopband, and the two TZs near the passband result in a higher selectivity. A resonant frequency centered at 7.45 GHz with an insertion loss of −1.21 dB and a measured return loss of higher than −23.53 dB and 3 dB fractional bandwidths of 5.8% are achieved. The stopband can be suppressed up to 20 GHz owing to the two tunable TZs resulting in higher selectivity and wideband rejection. The size of the filter was drastically optimized using a simplified architecture of two FOLRs and SLRs. Full article
(This article belongs to the Section Microwave and Wireless Communications)
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13 pages, 5584 KB  
Article
Fabrication of QFN-Packaged Miniaturized GaAs-Based Bandpass Filter with Intertwined Inductors and Dendritic Capacitor
by Jian Chen, Zhi-Ji Wang, Bao-Hua Zhu, Eun-Seong Kim and Nam-Young Kim
Materials 2020, 13(8), 1932; https://doi.org/10.3390/ma13081932 - 20 Apr 2020
Cited by 4 | Viewed by 3567
Abstract
This article presents a compact quad flat no-lead (QFN)-packaged second-order bandpass filter (BPF) with intertwined inductors, a dendritic capacitor, and four air-bridge structures, which was fabricated on a gallium arsenide (GaAs) substrate by integrated passive device (IPD) technology. Air-bridge structures were introduced into [...] Read more.
This article presents a compact quad flat no-lead (QFN)-packaged second-order bandpass filter (BPF) with intertwined inductors, a dendritic capacitor, and four air-bridge structures, which was fabricated on a gallium arsenide (GaAs) substrate by integrated passive device (IPD) technology. Air-bridge structures were introduced into an approximate octagonal outer metal track to provide a miniaturized chip size of 0.021 × 0.021 λ0 (0.8 × 0.8 mm2) for the BPF. The QFN-packaged GaAs-based bandpass filter was used to protect the device from moisture and achieve good thermal and electrical performances. An equivalent circuit was modeled to analyze the BPF. A description of the manufacturing process is presented to elucidate the physical structure of the IPD-based BPF. Measurements were performed on the proposed single band BPF using a center frequency of 2.21 GHz (return loss of 26.45 dB) and a 3-dB fractional bandwidth (FBW) of 71.94% (insertion loss of 0.38 dB). The transmission zero is located at the 6.38 GHz with a restraint of 30.55 dB. The manufactured IPD-based BPF can play an excellent role in various S-band applications, such as a repeater, satellite communication, and radar, owing to its miniaturized chip size and high performance. Full article
(This article belongs to the Special Issue Micro/Nanomechanics: From Theory to Application)
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