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Objective.Sjögren’s syndrome (SS) is an inflammatory autoimmune disease. We investigated important factors associated with the expression of inflammation-related molecules in minor salivary gland (MSG) mononuclear cells in patients with SS.Methods.Thirty-four patients with SS with a MSG biopsy grading of either grade III (10 patients) or grade IV (24 patients) were enrolled. The age, sex, autoantibodies, cell infiltration, and intercellular adhesion molecule-1 (ICAM-1), matrix metalloproteinase-3 (MMP-3), tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), or CXCR3 expression were also analyzed.Results.Ten of the 34 patients with SS were diagnosed with secondary SS; in these patients, the diagnosis of rheumatoid arthritis was confirmed in 8 and systemic lupus erythematosus in 2. TRAIL and ICAM-1 were overexpressed in patients with antinuclear antibodies (ANA) > 1:160, compared to those with titer < 1:160 (45.1 ± 4.4 vs 41.2 ± 3.9, p = 0.021, and 15.2 ± 5.7 vs 10.8 ± 3.3, p = 0.018, respectively). Higher erythrocyte sedimentation rate (ESR; ≥ 20) was associated with higher TRAIL expression and CD20 cell infiltration in contrast to lower ESR (< 20; p < 0.05). ICAM-1, TRAIL, and MMP-3 were expressed more predominantly in anti-SSA-positive than in anti-SSA-negative patients with SS. There was a significant difference in CD20 cell infiltration and MMP-3 expression between primary SS and secondary SS. Biopsy of a grade IV showed a significantly increased expression of TRAIL (44.9 ± 4.5 vs 40.8 ± 3.6, p = 0.013) and MMP-3 (62.7 ± 6.3 vs 54.4 ± 7.3, p = 0.003) in mononuclear cells as compared to those of grade III.Conclusion.In our study, pathologic grading with a higher grade (grade IV) and the presence of SSA or a higher titer of ANA were significantly associated with the overexpression of TRAIL, MMP-3, or ICAM-1 in the salivary gland mononuclear cells in patients with SS.

The study of biomarkers in spondyloarthropathy (SpA) has emerged to be a very important field of research. This is particularly because the two commonly used biomarkers, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), are of very low sensitivity and specificity. The second reason is, with advances in the treatment of SpA by the very expensive tumor necrosis factor-α (TNF-α) blockers, for cost-effectiveness, clinicians need to be much more accurate in predicting disease progression, evaluating disease activity and monitoring therapeutic efficacy. This review focuses on several biomarkers of promise: matrix metalloproteinases 3 (MMP-3), Type II collagen neoepitope (C2C and C1-2C), C-propeptide of Type II collagen (CPII), aggrecan 846 epitope, macrophage colony stimulating factor (M-CSF), serum amyloid A (SAA) and Interleukin-6 (IL-6). The results summarized in Table 1 call for a co-ordinated effort for systematic studies of existing biomarkers and for search for new candidates.

The reflection and radiation characteristics of a planar dielectric antenna with arbitrary geometrical configuration are analyzed numerically. A variational equation is first established based on the partial variational principle (PVP), and then solved by the finite element method coupled with the frontal solution technique. The radiation and boundary conditions are incorporated by combining the modal expansion method and the Green's function approach for exterior field representation. The reflection coefficients, the radiation patterns, and the directive and power gains of several antennas with linearized structures are studied and compared. >

Hemolytic uremic syndrome (HUS) consists of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. Autoimmune diseases have seldom been reported to be the etiology of HUS. Primary Sjogren’s syndrome (pSS) is a systemic autoimmune disease affecting primarily the exocrine glands. Symptomatic pericarditis and pulmonary hemorrhage are rare manifestations in pSS patients. We describe the unusual case of a pSS patient with the initial presentation of HUS and pericarditis and a fatal progression of pulmonary hemorrhage. A renal biopsy established the diagnosis of HUS with histologically proven arterial thrombotic microangiopathy and glomerular and tubular ischemic necrosis. The relationships between HUS and pericarditis and pSS will be discussed in this report.

In this work, a novel balanced-to-unbalanced (balun) diplexer is presented. By properly converting symmetric four-port balanced-to-balanced bandpass filter to a three-port device, a balun bandpass filter with high selectivity and extended stopband can be realized. Based on such a well-designed balun bandpass filter, a balun diplexer can be accomplished by combining two balun bandpass filter with two 50 matching lines. For demonstration, two fourth-order balun bandpass filters centered at 1.2 GHz and 1 GHz are employed to design and fabricate the balun diplexer. Specifically, the fabricated balun diplexer has the merits of compact size, wide stopbands, high isolation, and good common-mode rejection ratio.

Omnidirectional zero-$\overline{n}$ gaps in one-dimensional photonic crystals with a Fibonacci basis containing frequency dependent metamaterials are examined. In this study, the band structure and band gaps are determined by an explicit band-edge equation rather than by a traditional dispersion equation. We find that the present method has better numerical stability than traditional methods, especially for calculating the zero-$\overline{n}$ gap in the photonic crystals with metamaterials. We observe that the change in the width and location of the omnidirectional zero-$\overline{n}$ gap is limited for the Fibonacci photonic crystals with different generation orders. However, the width of the omnidirectional gap in the Fibonacci photonic crystals is significantly affected by the filling factor of the metamaterials. We also find that the width of the gap will be maximum at an optimum filling factor. The gap will vanish if the filling factor is greater than a critical value. Moreover, for a given filling factor and a metamaterial, it is interesting that the gap will be enlarged as the refractive index of the traditional layer increases.

Psoriasis and psoriatic arthritis (PsA) are interrelated disorders. To date, no study has compared the differences of genes between patients with PsA and psoriasis and healthy controls in a Chinese population. We conducted a retrospective study to determine the human leukocyte antigen (HLA) -A, -B, -Cw, -DR, and -DQ alleles in Chinese patients with PsA and psoriasis.HLA studies were performed using polymerase chain reaction sequence-specific oligonucleotide (PCR-SSO) genotyping methods in 91 patients with PsA and 80 with psoriasis and 75 controls. Age at disease onset, sex, disease duration, enthesitis, and uveitis were also analyzed.Among the patients with PsA and psoriasis, the frequency of HLA-B27 was significantly higher in PsA and HLA-A*30, -Cw*06, -DR*07 in psoriasis compared with controls. In contrast, HLA-B*58 was more common in controls than in PsA and psoriasis groups, and the prevalence of HLA-DR*17 was significantly higher in controls than in those with psoriasis. Comparing PsA and psoriasis, the prevalence of HLA-B*27 and HLA-Cw*12 were more common in PsA patients, while the prevalence of HLA-DR*07 was higher in those with psoriasis (p0.05). Among PsA patients, the association between HLA-B*27 and axial joint involvement and uveitis was significant (p0.05).Certain HLA alleles are found in Chinese patients with psoriasis (HLA-A*30, -Cw*06, -DR*07) and PsA (HLA-B*27). Psoriasis patients with the HLA-B*27 and/or -Cw*12 may have higher risk of developing PsA. Ours is the first study to assess the genetic role of HLA in patients with psoriasis and PsA in a Chinese population.

A perturbed-transverse electromagnetic (TEM) approach to studying the detailed current distribution and the propagation constant of a multiconductor transmission line system with imperfect conductors is discussed. The perturbed fields are derived assuming that the fields outside the conductors are TEM waves of the corresponding lossless system and those inside the conductors satisfy the transverse magnetic (TM) modal equations. These fields are then inserted into a perturbational formula to obtain the propagation constant of the lossy system. The current distribution and the propagation constant (which clearly illustrates the loss mechanism due to the skin effect and the proximity effect) of a lossy two-wire system are presented as an example. >

A study of a plane wave obliquely incident on a nonlinear slab of positive Kerr coefficient in total internal reflection (TIR) state is reported. Various bistable and multi-valued transmissions are investigated as the incident power varies. Especially, the mechanism of the resonant transmission is analyzed in detail, and an explanation of the invariance phenomenon in the first jump positions is proposed. Finally, a method for designing good bistable switchings is given.

A new full-wave analysis of coplanar waveguides is presented. The modified mapping technique of C.P. Wen (1969) is used to map the original infinite domain into a finite image domain and also to account for the singularity of fields near the conductor edges. The finite thickness of the dielectric substrate is considered together with the assumptions of lossless guides and negligible metallization thickness. The current distributions on the center signal strip as well as the tangential electric fields over the slot along the air-dielectric interface are examined. Numerical results for the frequency-dependent effective dielectric constants and characteristic impedances of coplanar waveguides are presented. Particular attention is given to the electric field distributions over the air-dielectric interface of slots and the current distributions of the signal strip. >

An improved combline bandpass filter with multiple transmission zeros is investigated in the study. To characterize the filter response, the characteristic equation of the proposed two-pole filter is derived and examined. In accordance with the derived characteristic equation, a lumped capacitor is attached between input and output ports so as to create more transmission zeros on the upper-stopband for providing the required attenuation for particular frequencies. Specifically, a multiple-notch two-pole combline filter is designed and fabricated with two transmission zeros around the passband for improved selectivity and another three on the upper-stopband for interference attenuation.

Design of a box-section filter with asymmetric frequency response would introduce non-zero diagonal elements in the coupling matrix. These non-zero diagonal elements would cause a shift of resonant frequency for each resonator and the coupling coefficients would not easily be determined accurately without heavy and complicated iteration process. In this paper, a new and simple design procedure for the asynchronous box- section filter is presented. Through the proposed design procedure, the dimensions of resonators and the coupling coefficients can be extracted systematically, and the iteration time for fine tuning can be reduced drastically. To demonstrate the benefit of proposed design procedure, a fourth-order multilayer box-section filter with one transmission zero is carefully designed, fabricated, and measured.

This paper is concerned with the design problem of the robust control for a networked control system (NCS) with time-varying communication delays. It has been known that time delays may not only degrade the system performance, but also destabilize the controlled plant. To alleviate the influence resulting from time delays while maintaining performance, a mixed fuzzy-PID/neural network compensating scheme is applied to pneumatic systems with uncertain communication delay. The experimental results verify effectiveness and superiority of our proposed approach.

The recent research efforts on microwave and millimeter-wave technologies in National Taiwan University (NTU) are presented in this paper. The scope of our researches includes passive elements, and monolithic microwave integrated circuits (MMICs), together with the device modelling, design methodology, measurement techniques, and system integrations. Major research programs at NTU will also be introduced.

The recent research efforts on microwave and millimeter-wave technologies in Taiwan are presented in this paper. The scope of our researches includes passive elements, and monolithic microwave/millimeter-wave integrated circuits (MMICs), together with the device modeling, design methodology, and measurement techniques. Also, the microwave industry is browsed to give a clearer picture of the combined efforts in promoting the microwave researches and development in Taiwan.

The purpose of this paper is to present a stable network control design with uncertain time-varying communication delays. In the typical networked control systems (NCSs), there are inherent plant delays and network delays. It has been know that time delays may not only degrade the system performance, but also destabilize the controlled plant. To alleviate the influence resulting from time delays while maintaining performance, we propose a compensating scheme which consists of two compensators-a fuzzy-PID controller and a neuron network compensator. The proposed design has also been experimentally verified to show its effectiveness and superiority.

A 60GHz six-port transceiver IC in a standard-bulk 0.13mum CMOS process is reported. This chip is composed of a VCO, a modified reflection-type I/Q modulator, a buffer amplifier, an SPDT switch, an LNA, and a six-port detector. The measured results show 4.5dB conversion gain and 4Gb/s modulation BW with 97.7mW DC power consumption.

A very compact ultra-wideband (UWB) bandpass filter with both high selectivity and suppressed spurious passband is implemented in the low-temperature co-fired ceramic (LTCC) substrate. By using the optimum distributed highpass filter structure of 11th-order, an ultra-wideband filter with the bandwidth from 3.1 GHz to 10.6 GHz is realized. In this study, the semi-lumped parallel resonance circuits are adopted in conjunction with the optimum distributed highpass filter, so that two finite transmission zeros may be created to suppress the spurious passband. The implemented filter exhibits a good frequency response to meet the Federal Communication Committee's (FCC's) limit and has a very compact size of 0.22 lambdag times 0.187 lambdag times 0.0246 lambdag (4.2 mm times 3.5 mm times 0.46 mm), where lambdag is the guided wavelength of the multilayer structure at 6.85 GHz.

New dual-plane bandpass filters based on the coplanar-waveguide (CPW) square-ring resonators are proposed. In this study, the elevated metal air-bridges are used to suppress the parasitic coupled slotline mode and also to provide the shunt- capacitance perturbation. Moreover, the microstrip-to-CPW T- shaped transition is utilized as the feeding structure so that a large coupling may be achieved without using the surface-mount ceramic capacitors. By taking advantages of dual-plane layout capability, a wide bandwidth filter may be realized. Specifically, two filters with 3-dB fractional bandwidth of 20.85% and 31% are implemented and measured. Agreement between the measured and simulated results is also observed.

A novel coplanar-stripline low-pass filter using lumped-element spiral inductors and interdigital capacitors is proposed. To characterize this filter, a simple CAD equivalent-circuit model is established. The elements of this model, which consist of transmission lines, resistances, inductances, and capacitances, can all be handled by the closed-form formulas; hence this model is suitable for CAD application. In this study, results based on CAD model, full-wave simulation, and measurement are presented, and good agreement among these results validates the usefulness of the proposed CAD model. Being compact and uniplanar in structure, this coplanar-stripline low-pass filter is useful in the implementation of monolithic microwave integrated circuits (MMIC's).

The compact coupled-line bandpass filters with two capacitive cross-couplings to create four transmission zeros are proposed. The locations of transmission zeros can be adjusted by varying the values of cross-coupled capacitances so as to improve the filter selectivity. To demonstrate the concept of multiple cross-couplings, a 4th-order microstrip coupled-line bandpass filter with four transmission zeros is implemented and examined. To further improve the stopband response, the coupled sections are shortened so that the spurious response may be suppressed. Specifically, another 4th-order microstrip coupled-line bandpass filter with spurious suppression around triple the center frequency (3f0) is also implemented.

A compact bandpass filter using both microstrip and coplanar waveguide (CPW) quarter- wavelength resonators is proposed. By combining the merits of two-layer layout and stepped-impedance resonators, a filter with various degree of couplings and reduced size may be realized. Moreover, due to the higher spurious resonant frequencies of stepped- impedance CPW resonators, the filter with wide stopband may be achieved. In this study, a compact fourth-order filter composed of two microstrip and two CPW quarter-wavelength resonators is demonstrated and fabricated on the FR4 substrate.

In this paper, the miniaturized microstrip interlocked-coupled bandpass filters are proposed. With the proper utilization of folded quarter-wavelength stepped-impedance resonators, the occupied area of coupled-resonator pair may be reduced. In order to introduce two transmission zeros near the passband, an additional open-stub section is inserted between the low- and high-impedance lines of the resonators to facilitate the generation of cross- coupled path. Making good use of folded quarter-wavelength stepped-impedance resonators, the filters with reduced size and sharp passband selectivity are fabricated and carefully examined. Good agreement between measured and simulated results is observed.

Novel microstrip diplexer structures composed of a dual-passband filter together with two matching circuits are proposed. By using only a single dual-passband filter, the proposed diplexer may be made compact when compared with the conventional diplexer configuration which has two single- passband filters. In this study, the dual-passband filter is realized using the parallel-coupled microstrip structures, and the matching circuits are developed based on the stepped- impedance transmission-line sections along with suitable open stubs. By suitably incorporating the open stubs into the matching circuits, a 3 rd-order Chebyshev microstrip diplexer with dual center frequencies at 2.36 GHz and 5.17 GHz and an acceptable isolation is implemented.

Compact stopband-extended microstrip bandpass filters based on folded quarter-wavelength resonators are proposed. By introducing the source-load cross coupling, two transmission zeros may be created to improve the filter selectivity without degrading the passband insertion loss. In order to extend the rejection bandwidth, suitable open stubs or meander stepped-impedance resonators are adopted in the filter design. In this study, two compact microstrip filters are implemented, the first one uses open stubs to suppress the spurious response around 3f0 and the second one employs the meander quarter-wavelength stepped-impedance resonators to push the first spurious response up to 3.6 f0, where f0 is the passband center frequency. Good agreement between simulated and measured responses of these filters is demonstrated

A novel dual quarter-wavelength (lambda/4) hairpin microstrip resonator is proposed, which is composed of two lambda/4 stepped-impedance resonators (SIR's) that are coupled through a shorted stub section. In this study, the dual resonator structure is utilized to design a bandpass filter for which the filter order may be doubled and the via number required in the conventional lambda/4 filter may be reduced to half. Specifically, a four-pole quasi-elliptic microstrip filter is realized with two pairs of transmission zeros created around the passband edges so that the filter selectivity may be improved

111In-DTPA octreotide (DTPAOC) has been used for detecting somatostatin receptor positive tumor for years. In-111 DOTA-Tyr3-octreotide (DOTATOC) is newly developed for diagnostic and therapeutic purposes. In this study, we compared the biodistribution and tumor uptake ratio after injection of In-111 DTPAOC and In-111 DOTATOC in rats. Twelve rats bearing pancreatic tumors were divided into two groups: six rats were sacrificed at 4 hr after injection of 3.7 MBq of In-111 DTPAOC and another 6 rats were sacrificed at the same time after injection of 3.7 MBq of In-111 DOTATOC. Samples of various organs were obtained and counted to calculate the tissue concentration. In addition, 12 rats bearing pancreatic tumors were scanned at 4, 24, and 48 hr after injection of 37 MBq of In-111 DTPAOC or In-111 DOTATOC. The tumor uptake ratios (T/N ratio) were calculated. The biodistribution data showed that the activity in the tumor as well as in the kidney was significantly higher in the In-111 DOTATOC group than in the In-111 DTPAOC group, although both radiopharmaceuticals had the expected high affinity to the tumor. The T/N ratios in the In-111 DOTATOC group were also significantly higher than those in the In-111 DTPAOC group at 24 hr after injection. We conclude that In-111 DOTATOC showed lower clearance than In-111 DTPAOC in the rats bearing pancreatic tumors, although both of these radiopharmaceuticals showed expected high tumor uptake.

Pulmonary arterial hypertension (PAH), a serious complication of autoimmune diseases, has rarely been reported in Taiwan.Nineteen patients with various autoimmune diseases diagnosed with PAH at Taipei Veterans General Hospital from 2002 to 2004 were enrolled; the underlying autoimmune diseases included systemic lupus erythematosus (n = 6), primary Sjögren's syndrome (n = 5), systemic sclerosis (n = 4), adult-onset Still's disease (n = 2), and mixed connective tissue disease (n = 2). The characteristic manifestations of underlying autoimmune diseases and the clinical features of PAH were analyzed.There were 16 female and 3 male patients. The median age at onset of PAH was 44 years and the mean right ventricular systolic pressure (RVSP) was 67.9 mm Hg. Patients without pneumonitis had a significantly higher RVSP value than those with pneumonitis (77.5 +/- 24.3 vs 54.8 +/- 18.4 mm Hg, p=0.041). Four out of 7 patients (57.1%) with RVSPor=80 mm Hg and 1 out of 12 patients (8.3%) with RVSP80 mm Hg died. In all of the 19 patients, the severity of RVSP was significantly correlated with serum uric acid (UA) level (r = 0.686, p=0.001). Among the PAH patients without pneumonitis, the severity of RVSP inversely correlated with the diffusion capacity of the lung for carbon monoxide (DLCO) [r = -0.856, p=0.003]. The characteristic manifestations of underlying autoimmune diseases included a high incidence of Raynaud's phenomenon (15/19, 78.9%), a high titer of antinuclear antibody (13/17, 76.5%), positive anti-ribonucleoprotein antibody (8/15, 53.3%), hypergammaglobulinemia (15/19, 78.9%), hyperuricemia (13/19, 68.4%), and less renal involvement.PAH in autoimmune diseases could be potentially fatal with characteristic manifestations. Moreover, RVSP correlated directly with serum UA level and inversely with DLCO.

A novel parallel coupled-line microstrip bandpass filter with multiple transmission zeros is proposed. This filter exhibits low in-band insertion loss and good stopband rejection with the spurious passbands pushed to the higher frequencies. Specifically, a microstrip filter, with the center frequency designed at f/sub 0/ = 2GHz, having 16.3% 3-dB bandwidth, and a rejection band extended up to 6 f/sub 0/, is implemented and carefully examined.

Highly selective microstrip bandpass filters for UWB applications are proposed, by using the optimum distributed highpass filter structure of 11th-order to achieve a wide bandwidth from 3.1 to 10.6GHz as well as good selectivity. In addition, suitable filter layout is adopted to reduce the filter size and the number of vias required. Specifically, two compact 11th-order UWB microstrip bandpass filters with good selectivity are implemented and carefully examined.

Novel compact parallel-coupled bandpass filters are proposed, by using additional lumped-element capacitor as J-inverter between short-ended coupled-line sections to achieve an equivalent to the quarter-wavelength resonator filters. As a result, the filter order can be doubled without increasing the circuit area, and no repeated passband at twice the center frequency is observed. In addition, lower power loss is obtained compared to the previous works based on open-ended coupled-line sections. By introducing an inductive cross-coupling effect, two transmission zeros at upper and lower stopbands may also be created. The locations of the transmission zeros may be simply adjusted by varying the cross-coupling inductance. Simple equivalent-circuit models along with design equations are also established, from which the proposed parallel-coupled bandpass filters with lumped-element J-inverter may be designed and investigated. Specifically, several compact 2nd-order microstrip bandpass filters with good selectivity are implemented and carefully examined.

This article describes the successful experiences of National Taiwan University Hospital (NTUH) in moving from IBM Mainframe to connected networking computer systems. We use multi-tier architecture and HL7 standard to implement our new outpatient Hospital Information System (HIS). The NTUH HIS is a complex environment with several operating systems, databases, and information systems. We adopt Service- Oriented Architecture (SOA) to reduce the complex relations between systems and solve data consistency problems among databases. We also show that the distributed architecture can provide us stable and reasonable system performances. Our main contribution is proving that the distributed environment with HL7 standard and SOA can sustain in a highly demanding environment.

A 60GHz SiGe HBT transmitter IC with integrated antenna in a standard-bulk 0.18mum SiGe BiCMOS process is reported. This chip is composed of a VCO, a sub-harmonic mixer, a PA, and a tapered-slot antenna, all with differential designs. The measured results show 15.8dBm output power and 20.2dB conversion gain with 281mWdc power consumption

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Middle lobe syndrome - recurrent atelectasis and/or bronchiectasis involving the right middle lobe and/or lingula - has, up to now, not been reported as the pulmonary manifestation of primary Sjogren's syndrome. We describe a patient in whom lymphocytic bronchiolitis in the atelectatic lobes was proved histologically from two separate transbronchial biopsies. The atelectasis responded well to glucocorticoid treatment, suggesting that the peribronchiolar lymphocytic infiltrates may have played an important role in the development of middle lobe syndrome in this patient.

Compact coplanar-waveguide (CPW) bandpass filters are proposed, by introducing additional lumped inductor and capacitors to realize K-inverters in the conventional CPW parallel-coupled filter structure for achieving an equivalent to the quarter-wavelength resonator filters. As a result, the filter size may be reduced by about half. In addition, by introducing the cross-coupled effect, two transmission zeros at upper and lower stopbands may be created. Simple equivalent-circuit models are also established as effective design tools. Specifically, two CPW bandpass filters centered at about 40GHz with compact sizes and good selectivity are implemented and carefully examined.

Microstrip bandpass filters with an extended rejection bandwidth are proposed, using dissimilar resonators for spurious suppression. The combination of dissimilar resonator structures with same fundamental frequency but with different spurious frequencies may improve the stopband rejection of a bandpass filter by the partially mutual cancellation of spurious responses. Specifically, a 4th-order coupled-resonator microstrip bandpass filter, centered at f/sub 0/=1.97GHz, with better than 21.48 dB stopband rejection up to 9.72 GHz (4.93f/sub 0/) is implemented and investigated.

Compact microstrip bandpass filter with two transmission zeros is proposed based on one-eighth wavelength (/spl lambda//8) coupled-line sections. The proposed filter occupies only half of the circuit area of conventional parallel coupled-line bandpass filter, and exhibits good stopband rejection with no repeated passband at twice center frequency. By introducing a cross-coupled shunt inductor, two transmission zeros at upper and lower stopbands may be created without increasing the circuit area. The desired locations of transmission zeros can be adjusted by varying the value of cross-coupled inductance. Specifically, a microstrip coupled-line bandpass filter centered at 2.45 GHz with a 3dB bandwidth of 9.6% and two transmission zeros is implemented.

A compact coupled-line bandpass filter with two capacitively cross-coupled paths to create multiple transmission zeros is proposed. The locations of transmission zeros can be adjusted by varying the values of cross-coupled capacitances so as to improve the filter selectivity. Specifically, a 4th-order microstrip coupled-line bandpass filter centered at 4.9 GHz with a 3-dB bandwidth of 6% and six transmission zeros is implemented and examined.

Novel miniature parallel-coupled bandpass filters are proposed, by using additional lumped capacitors to reduce the lengths of coupled-line sections. With the lumped-element K-inverters at the input/output and between coupled-line sections, the proposed filter may be equivalent to the quarter-wavelength resonator filter such that no repeated passband at twice the center frequency is observed. In addition, by introducing the capacitive cross-coupling effect, two transmission zeros can be achieved. The locations of the transmission zeros may be simply adjusted by varying the cross-coupling capacitance. Simple equivalent-circuit models along with design formulas are also established, from which the proposed parallel-coupled bandpass filters based on lumped-distributed coupled-line sections may be designed and investigated. Specifically, a miniature 4th-order microstrip bandpass filter with good selectivity and stopband rejection is implemented and carefully examined.

A microstrip coupled-line bandpass filter with good stopband rejection is proposed. By introducing an additional shunt inductance to the conventional coupled-line filter, along with the capacitively coupled gap between coupled-line sections, two attenuation poles at upper and lower stopbands may be achieved without increasing the circuit area. The proposed filter exhibits good stopband rejection with no repeated passband at twice the center frequency as compared to the conventional coupled-line filters. Specifically, a microstrip coupled-line bandpass filter centered at 2.4 GHz with 5.4% 3-dB bandwidth and two attenuation poles is implemented.

Operating delay time in the solenoid valves is common in the practical electro-hydraulic servo systems. This may sometimes cause closed-loop instability if it wasn't treated carefully in the control system designs. We propose a non-model-based design approach for hydraulic actuating systems based on a new time-delay compensation scheme. In the proposed system, two types of controllers are combined; one is a fuzzy-PID controller used to ensure tracking performance, the other one is an adaptable wavelet compensator used to compensate for the time delay resulting from the control valve. Performance of the proposed design is widely verified on a newly developed simulation platform to show its effectiveness.

A miniaturized uniplanar GaAs MMIC HEMT mixer is proposed based on a compact multifunction transition structure. By the independence nature of the coplanar-waveguide (CPW) mode and the coplanar-stripline (CPS) mode, a compact transition which converts the CPW mode into the CPS mode is realized. This transition structure also has the functions of 180/spl deg/ hybrid, RF and LO diplexer, and bandpass filter. Thus the size of the proposed mixer may be drastically reduced, and the LO-to-IF and LO-to-RF isolations and RF conversion gain are excellent. This mixer is designed to operate with RF frequency from 35 to 40 GHz, IF frequency from 0.5 to 6 GHz, and LO frequency at 35 GHz. The lower sideband conversion gain is about 5 dB, the single-sideband (SSB) noise figure is 6.5 dB, the isolations are all better than 30 dB, and the size of the mixer is much compact than those of the conventional mixers.

A uniplanar coplanar waveguide-fed dual exponentially tapered slot antenna is proposed, using a lumped-element impedance-transforming coplanar waveguide-to-slotline transition as the antenna feeding structure. The proposed antenna features a compact size, wide impedance bandwidth, and consistent radiation patterns over the low-band of the ultra-wideband (UWB) spectrum. The characteristics of the proposed antenna, in both the frequency and time domains, are carefully investigated. It is demonstrated that minimum distortion to the UWB input pulse can be expected.

This paper presents a complete portfolio of silicon integrated RF power MOS using 0.18/spl mu/m CMOS technology in the first time. The proposed structure of power MOS promises high breakdown voltage, and presents excellent RF characteristics. To guarantee the production level, a complete qualification testing is also included.

A new coplanar-waveguide coupled structure is proposed by incorporating a backed conductor on the other side of the substrate. For this new coupled structure, the effective dielectric constants as well as the characteristic impedances of the odd and even modes are calculated by the spectral-domain method. In this study, the proposed coupled structure is characterized by carefully examining the related coupling coefficient and the associated field distributions.

Novel reduced-size lumped-element coplanar waveguide-to-slotline transitions are proposed, using planar parallel LC circuits to replace the /spl lambda//4 transformer structure. A simple equivalent-circuit model is also established, from which various lumped-element transition structures are carefully examined. Specifically, a "ring-type L" lumped element transition with a 1.8:1 bandwidth and 1/12 the size of conventional ones is achieved.

This paper proposes a new flip chip structure which uses resonating dual bumps to achieve best transition. By simply changing the distance between the two bumps, we can control the band of minimum reflection in the desired frequency band. The bandwidth over which the return loss is smaller than -20 dB is 20-30%. The corresponding insertion loss in this band is less than -1.5 dB. All, results presented are simulated with the FDTD method combined with PML.

A uniplanar GaAs MMIC diode mixer is fabricated for Q-band applications using the lumped-element coplanar waveguide-to-slotline transition to implement the required 180/spl deg/ hybrid. By adopting the lumped-element transition, the mixer chip size can be largely reduced with an excellent RF-to-IF isolation. This mixer is designed to operate with RF frequency from 34.5 to 43 GHz, IF frequency from 0.5 to 9 GHz, and LO frequency at 34 GHz. The lower sideband conversion loss is about 7 dB, and the isolations are all better than 20 dB. To our best knowledge, it is the first MMIC with such transition topology in Q-band.