60 GHz compact integrated cross-coupled SIR-MH bandpass filter on bulk CMOS

A new 60 GHz fourth-order cross-coupled bandpass filter using a step- impedance-resonator (SIR) miniaturised open-loop resonator and the miniaturised-hairpin (MH) resonator was designed and fabricated on 0.13 mum bulk CMOS. It has 8.5 GHz (58-66.5 GHz) bandwidth, 5.9 dB insertion loss, and better than 10 dB return loss over the whole passband, and exhibits high selectivity and a compact size of 714.9 times 484 mum (0.346 mm ). This filter is the first reported cross-coupled filter above 40 GHz on CMOS.     

Compact Thermally Tunable Silicon Wavelength Switch: Modeling and Characterization

A wavelength-selective photonic switch is developed based on a Si microring resonator using thermooptic effect. The 10-mum-diameter microring resonator uses single-mode strip Si waveguides of dimension 0.25 mum times 0.45 mum operating at 1.5 mum. Full-width at half-maximum are in the range 0.1-0.2 nm. The ultrawide tunable range (>6.4 nm) and wide free spectral range (~18 nm) of the switch element enables wavelength reconflgurable multichannel matrix switch by wavelength multiplexing/demultiplexing. Average rise delay time of 14 mus with low switching power of 3.15 mW has been achieved with 0.2-nm wavelength tuning and 78 mus, 104 mW for 6.4-nm tuning. Fall delay times are usually less than 10 mus. Thermal simulations show 10%-20% agreement with the measurements up to 3.2-nm tuning. The compact size of the switch shows its potential as an active element in photonic integrated circuits.     

Compact gap coupled resonator using negative refractive index microstrip line

A compact gap coupled resonator implemented with a negative refractive index microstrip line section is presented. The resonator offers harmonic suppression and an 86% size reduction compared to a conventional gap coupled resonator operating at 1.2 GHz. The resonator should have many applications in the design of filters and oscillators.     

40 GHz compact TFMS meander-line bandpass filter on silicon substrate

Presented is a compact millimetre-wave bandpass filter using a thin-film microstrip meander line on standard 0.18 mum CMOS silicon substrate without any post-processing step yet still reducing the substrate loss and crosstalk to a large extent. To miniaturize overall circuit size, a half-wavelength resonator is constructed in meander-line configuration and its resonant frequency is designed to be 40 GHz. The prototype single-resonator bandpass filter occupies a circuit area of 210 times 210 mum on silicon. Measured insertion loss is 2.5 dB, which agrees well with the design value in the simulations.     

Driving Characteristics of a High-Efficacy AC PDP With an Auxiliary Electrode

A new driving waveform was proposed in order to stabilize the driving characteristics of a high-efficacy AC plasma-display panel (PDP) with a coplanar gap of 200 mum and an auxiliary electrode. To stabilize the reset and address discharge, an erase pulse was applied to the auxiliary electrode instead of the sustain electrode after the sustain period. The write pulse was applied to the scan electrode, and a reset discharge was induced between the scan and auxiliary electrodes. As a result, the minimum address voltage could be reduced to a level similar to that achieved with a conventional ac PDP with a coplanar gap of 80 mum. Furthermore, the address-discharge time lag of the ac PDP with a coplanar gap of 200 mum was improved to a level that is comparable with that of the ac PDP with a coplanar gap of 80 mum.     

A 3.3 mW K-Band 0.18-μ m 1P6M CMOS Active Bandpass Filter Using Complementary Current-Reuse Pair

This letter presents a low-power active bandpass filter (BPF) at K-band fabricated by the standard 0.18 mum 1P6M CMOS technology. The proposed filter is evolved from the conventional half-wavelength resonator filter, using the complementary-conducting-strip transmission line (CCS TL) as the half-wavelength resonator. Furthermore, the complementary MOS cross-couple pair is proposed as a form of current-reuse scheme for achieving low-power consumption and high Q-factor simultaneously. The simulated results indicate that the Q-factor of the proposed half-wavelength resonator can be boosted from 9 to 513 at 25.65 GHz compared with the resonator enhanced by the nMOS cross-couple pair to Q-factor of merely 43 under the same power consumption. The proposed active BPF of order two occupies the chip area of 360 mum times 360 mum without contact pads. The measured results show that the center frequency of the active BPF is 22.70 GHz and a bandwidth of 1.68 GHz (7.39 %). The measured P_{1 dB} and noise figure at 22.70 GHz are -7.65 dBm and 14.05 dB, respectively. There is a 56.84 dB suppression between the fundamental tone and the second harmonic when the input power is -11.26 dBm. While showing 0 dB loss and some residual gain, the active BPF consumes 2.0 mA at 1.65 V supply voltage with maximum of 0.15 dB insertion loss and 9.96 dB return loss at pass band.     

Wavelength-Tunable Microring Resonator on Lithium Niobate

A wavelength-tunable microring resonator with integrated microheater on lithium niobate is presented. Ridge structure on lithium niobate is formed by a wet-etching technique for enhancing the lateral index contrast of the waveguide. The resonant wavelength of the microring resonator is tuned through thermooptic effect by injecting current into the integrated microheater. The tuning characteristics of through port and drop port are measured and the tuning rates in the microring resonator with a radius of 100 mum for transverse-magnetic and transverse-electric polarizations are 2.54 x 10^-2 nm/mA and 3.40 x 10^-3 nm/mA.     

缩短微机械圆盘谐振器缝隙的电极移动法

针对现有微机械(Micromechanical,也称MEMS)圆盘谐振器串联动态电阻过大的问题,该文提出了电极移动法,将其它MEMS器件的可调性能引入MEMS圆盘谐振器,在现有最窄缝隙工艺条件下实现了电极-圆盘缝隙的进一步缩减,降低了串联动态电阻。该文给出了悬置电极的设计方法,推导了电极移动后有效缝隙宽度的表达式,提出了可防电极接触短路的微小圆孔状凹陷设计,并给出了加入凹陷后的有效缝隙宽度表达式。通过ANSYS仿真结果可知,分别加载2.10 V和66.38 V偏置电压后,0.1 m和1 m电极-圆盘缝隙缩小为0.0016 m和0.01 m。对于0.1~1.1 m缝隙谐振器,串联动态电阻变为原来的10-8倍以下。     

Single-Facet Folded-Cavity Diode Laser With Ultrasmall Bend Radius High-Index-Contrast Oxidized AlGaAs Ridge Waveguide

AlGaAs heterostructure high-index-contrast (HIC) ridge waveguide (RWG) diode lasers incorporating a folded-cavity single-facet resonator with a folding bend radius as small as r=10 mum are demonstrated. Fabricated by a self-aligned deep dry etch (through the active region) plus nonselective O₂-enhanced wet thermal oxidization process, the low-index, insulating, and interface-passivating wet thermal oxide grown directly on the etch-exposed AlGaAs waveguide sidewalls yields a high lateral refractive index contrast of Deltan~1.7 and provides strong optical mode confinement. The HIC RWG device geometry also completely eliminates lateral current spreading, which results in an excellent overlap between the optical field and the gain region of the single InAlGaAs quantum-well graded-index separate confinement heterostructure. A threshold current of I_th=65mA is obtained for the r=10 mum device (a half-racetrack ring resonator), giving a threshold current density of Jth=1503 A/cm², 3.34 times higher than that of same-length straight lasers. At a bend radius of r=150 mum, I_th=16.6 mA, and J_th is comparable to straight cavity values, indicating that at this curvature there is negligible bending and scattering loss for the lowest-order waveguide mode     

CDMA系统用高性能高温超导滤波器的研制

本文研制了用于CDMA移动通信系统的高性能高温超导滤波器。该滤波器中心频率为832MHz,带宽为6MHz（相对带宽为0.72%）。为了实现结构紧凑的滤波器,采用了线条宽度和间距均为80μm的双螺旋形谐振器,在MgO基片上实现的12节滤波器尺寸仅为41.4mm×14mm。对滤波器的敏感度分析结果表明,该滤波器的频率响应特性对基片参数和仿真Cell尺寸的变化不敏感,具有较高仿真准确度。滤波器制备采用了高精度光刻和离子束刻蚀工艺,实际测试结果与仿真结果吻合得很好,并且无需调谐即表现出良好性能,插入损耗小于0.36dB,反射损耗大于15.6dB,带外抑制大于100dB。     

Integration of microwave phase shifter with BST varactor onto TiO/sub 2//Si wafer

A BST ferroelectric thin-film microwave phase shifter with interdigital capacitors on TiO₂/Si substrate is presented. The interdigital capacitors have 230 mum signal width, 100 mum signal to ground gap, and 10 mum finger gap. The device, with phase shifts of 142deg and FoM of 107.3deg/dB applied voltage of 50 V at 16 GHz, has been realised. The TiO₂ buffer layer grown by ALD enables successful integration of BST-based microwave tunable devices with Si wafer.     

Dielectric ring-gap resonator for application in MMIC's

A dielectric resonator, the dielectric ring-gap resonator, is introduced and analyzed. The dielectric ring-gap resonator is obtained by sawing a narrow gap into a dielectric resonator. Resonant frequencies and unloaded Q-factors of quasi-TE_0pq mode in the ring-gap resonator have been calculated by an appropriate equivalent circuit starting from the resonant frequencies and the field distributions of the TE_0pq modes in the ring resonator. The calculated resonant frequencies of the fundamental quasi-TE₀₁₁ mode show an accuracy of <1% compared with the experimental results. Coupling techniques to couple the ring-gap resonator to a microstrip line on a thin substrate, using the electric fringing field near the gap, have been experimentally investigated. A rigorous method for determining resonant frequencies and field distributions of TE modes in a multicomposite multilayered cylindrical resonator is presented. This resonator consists of numbers of cylinders that are arbitrarily layered in the axial direction     

Miniature high gain slot-fed rectangular dielectric resonator antenna for IoT RF energy harvesting

Radio-frequency (RF) energy harvesting is a promising candidate for alternative power source that can reduce the dependencies on batteries. However, its power density is very low which makes it crucial to have a high gain antenna to increase the power received by the system. This study presents the design of miniature high gain dielectric resonator antenna for RF energy harvesting application with high figure of merit to increase the power received. Numerical approximation is used to assist the antenna design and modelling. The design focused on three parameters which are the width, length, and height of the dielectric resonator. The performance, electric field density, and the radiation patterns of the dielectric resonator antenna have been observed by varying the design parameters. The effect of air gap to the performance is investigated and it is found that 8.11–13% gain improvement and up to 36% improvement in impedance matching is achieved through incorporating thin air gap between the dielectric resonator. Soda-lime glass with relative permittivity 7.75 is used which allows miniaturization and transparency. Experimental results show reasonable agreement to the simulations. The work shows highest antenna gain with smallest size with high FOM at 5 GHz ISM band compared to previous works.     

Monolithic CMOS MEMS Oscillator Circuit for Sensing in the Attogram Range

This letter presents the design, fabrication, and demonstration of a CMOS/microelectromechanical system (MEMS) electrostatically self-excited resonator based on a submicrometer-scale cantilever with ~1 ag/Hz mass sensitivity. The mechanical resonator is the frequency-determining element of an oscillator circuit monolithically integrated and implemented in a commercial 0.35 mum CMOS process. The oscillator is based on a Pierce topology adapted for the MEMS resonator that presents a mechanical resonance frequency of ~6 MHz, a relative low quality factor of 100, and a large motional resistance of ~25 M. The MEMS oscillator has a frequency stability of ~1.6 Hz resulting in a mass resolution of ~1 ag (1 ag = 10^-18 g in air conditions.     

Implementation of higher order forced oscillations mode in shielded dielectric resonators by using slotline

The electromagnetic characteristics of the shielded hemisphere dielectric resonator in 8-mm waveband were investigated experimentally. The utilization of a slotline for the excitation of whispering gallery modes in such resonator was suggested. It has been defined that the suggested excitation technique is efficient. It provides an opportunity to excite the high Q-factor higher order modes in shielded dielectric resonator without additional energy losses. It has been proved experimentally that the unloaded Q factor achieved in the resonator under investigation may exceed the threshold values, which are limited by the dissipative losses in the dielectric resonator material, due to the shift of the resonance field in the air gap between the metal and the dielectric resonator elements. It was demonstrated that the symmetry breakdown of the investigated resonator leads to a significant deterioration of its electromagnetic characteristics.     

Photonic-crystal surface-emitting laser near 1.55 /spl mu/m on gold-coated silicon wafer

An InP/InGaAs-based photonic band-edge laser bonded on silicon operating near 1.55 mum is presented. A gold reflector positioned below the slab containing the active layer reduces the optical losses of the Bloch-mode resonator. As a result, a quality factor exceeding 8000 is obtained at transparency leading to a laser threshold as low as 3.4 muJ/cm²     

声表面波器件中非同步区域体波散射的抑制

用有限元/边界元法(FEM/BEM)研究了表面波器件中非同步区域中体波散射引起的损耗。以典型的hiccup单端对谐振器作参考结构,用结构参数缓慢变化的间隙取代其中间的自由间隙。研究发现,改变间隙参数可在保持谐振频率不变的同时,提高谐振器的品质因数值。对分布间隙和风琴间隙两种间隙结构进行对比,结果表明,前者优于后者。将传统DMS滤波器中的金属化间隙以分布间隙取代,可找到一个优化的分布间隙结构,使插损提高0.3 dB。     

A W-Band Air-Cavity Filter Integrated on a Thin-Film Substrate

In this letter, a W-band air-cavity filter has been developed on a thin-film substrate using a lossy silicon substrate as a base plate, which is suitable for a mm-wave system-on-package. The lossy silicon suppresses a parasitic substrate mode excited in a thin-film substrate, while a coupling loss between a transmission line and a resonator is minimized by etching the backside of the lossy silicon substrate underneath the coupling area. In the backside etching process, 70 mum of silicon was left for mechanical support of the thin-film substrate. The resonator was fabricated using a low-cost silicon micromachining technique and was flip-chip integrated on a thin-film substrate. The fabricated air-cavity resonator showed an unloaded Q of 851 at a resonant frequency of 94.18 GHz. Improvement in the coupling loss by the backside etching process was verified with measurement results. The fabricated filter exhibited an insertion loss of 1.75 dB and a return loss better than 14.5 dB with a 1.3% 3 dB fractional bandwidth at a center frequency of 93.8 GHz.     

Dual-mode quasi-elliptic-function bandpass filters using ringresonators with enhanced-coupling tuning stubs

A novel microwave dual-mode quasi-elliptic-function bandpass filter structure has been designed and fabricated. The filter uses L-shaped coupling arms for enhanced coupling and dual-mode excitation. The effects of varying the length of tuning stubs and gap size between tuning stubs and ring resonator have been studied. Filters using multiple cascaded ring resonators with high rejection band are presented. The new filters have been verified by simulation and measurement with good agreement     

可调谐氮化硅波导微环谐振腔滤波器研究

设计并制备了一种基于热光效应的集成可调谐氮化 硅(Si₃N₄)波导微环谐振腔滤波器,通过采用马赫-曾德干涉仪(MZI)构成的可调谐 耦合器控制耦合区耦合比,以实现滤波器消光比的调谐。设计并优化了微环谐振 腔的波导截面尺寸、弯曲半径和耦合区波导间隔等参数,并通过光刻、反应离子刻蚀(RIE )等工艺制备 了两种不同弯曲半径的Si₃N₄波导微环谐振腔。实验结果表明,本文器件在波长1550nm附近处的自由光谱 范围(FSR)为68pm,3dB带宽约为16pm,品质因子Q达到了9.68×10 4,消光比可调范围约为17dB。