Four-channel wavelength division multiplexers and bandpass filtersbased on elliptical Bragg reflectors

Four-channel multiplexers and four-wavelength bandpass filters based on elliptical Bragg reflectors (EBRs) are discussed. The channel spacing is 50 Å near 1.56 μm. The EBRs are narrowband elliptical mirrors that can refocus light from an input waveguide to any one of a number of output waveguides. Spectrally, they perform similarly to Bragg reflectors. The devices were fabricated on silicon using silica-based waveguide technology. The elliptical gratings with 0.53-μm periods were patterned using deep UV spatial frequency doubling photolithography. Multiplexers with single filtering and double filtering were demonstrated. With single filtering, the fiber-to-fiber insertion loss was 3.0±0.5 dB, and the crosstalk was -20 dB; with double filtering, the insertion loss was 4.0±0.5 dB, and the crosstalk was -30 dB. About 2 dB of this loss was due to coupling between the fibers and the waveguide. The additive loss associated with the EBR, including propagation, Bragg reflection, and coupling between input and output waveguides, was about 1 dB     

一种高线性度非对称单刀双掷开关的设计

介绍了一种用于射频收发系统的16 GHz、低损耗、高隔离度、高线性度的非对称型单刀双掷开关。针对串联和并联晶体管尺寸对插入损耗及隔离度的影响、对称型和非对称型两种结构各自的特点,以及选择非对称结构的原因进行了分析。采用90 nm CMOS工艺实现,设计中采用深N阱MOS管,并在必要的节点加入交流悬浮偏置,提高开关整体性能。测试表明,Rx模式下,插损为0.77 dB,隔离度为22.9 dB,输入1 dB压缩点为9 dBm;Tx模式下,插损为2.14 dB,隔离度为20.2 dB,输入1 dB压缩点大于15 dBm。     

Influence of water sorption on acrylic polymer waveguide loss

The influence of water sorption on acrylic polymer waveguides was studied by measuring the loss changes in the atmosphere at 13 to 98% RH. The absorption peak at 1.41 μm increased from 0.5 to 2 dB/cm due to water sorption. This peak resulted in a small loss change of 0.03 dB/cm at 1.3 μm, which was successfully measured using a 57 cm waveguide with a loss of around 0.1 dB/cm. Relationships between loss change and water sorption were also revealed by measuring the water content of the polymers     

An Integrated-Circuit Balanced Mixer, Image and Sum Enhanced

GaAs Schotty-barrier diodes with a zero-bias cutoff frequency of 800 GHz have been used in an integrated-circuit balanced diode mixer operating with a signal frequency centered at 9.3 GHz and a local-oscillator (LO) frequency at 7.8 GHz. For an instantaneous bandwidth of 1.0 GHz, the conversion loss (including all circuits and connector losses) was under 3.15 dB. Over the center 0.5 GHz of the band, the conversion loss was less than or equal to 2.8 dB. The conversion loss at the image-band edges was greater than 25 dB; the loss at the center of the image band was greater than 35 dB.     

A long InGaAsP/InP waveguide section with small dimensions

A spirally folded InGaAsP/InP ridge-type waveguide with 12.4 mm length, corresponding to 4-cm free-space length, on a device area of 1 mm×1 mm, was realized. Insertion loss was measured to be 4 dB for TE-polarization and 4.5 dB for TM-polarization, most of which is caused by normal propagation loss (2 dB/cm for straight waveguides). Excess bending loss is estimated to be 1.5 dB for TE and 2 dB for TM-polarization     

Low-loss laser diode module using a molded aspheric glass lens

The fabrication and characteristics of a 1.3-μm laser diode (LD) module for single-mode fiber using a molded aspheric glass lens is discussed. An average coupling loss of 2.2 dB with a standard deviation of less than 0.5 dB after thermal heat cycling tests was achieved. The average assembly loss was 0.24 dB. The LD module demonstrated stability during thermal and heat cycling tests from -10 to 60°C     

Fluorinated polyimide waveguides with low polarization-dependentloss and their applications to thermooptic switches

Fluorinated polyimide waveguides with low polarization dependent loss (PDL) and thermooptic (TO) switches made from them were demonstrated. The waveguides showed loss of less than 0.3 dB/cm at the wavelength of 1.3 μm and 0.6 dB/cm at 1.55 μm for both TE and TM polarizations. The PDL's were less than 0.1 dB/cm. Extinction ratios of Y-branching-type TO switches fabricated from these waveguides were larger than 20 dB when over 160 mW of electric power was applied at 1.3 μm, and over 150 mW at 1.55 μm. The switching speed was faster than 8 ms     

改进型3IDT-LCR结构的低损耗小矩形系数SAW滤波器

通过理论仿真,该文研制了一种改进型的3IDT-LCR结构,并基于该结构在42°Y-X LiTaO₃压电基片上研制出一种低损耗、小矩形系数的SAW滤波器。滤波器标称频率为253.75 MHz,实测插入损耗1.05 dB,低端带外抑制接近80 dB,高端带外抑制接近65 dB,-1 dB带宽10.52 MHz,-3 dB带宽12.54 MHz,-40 dB带宽16.68 MHz,矩形系数1.33。实测结果表明,该改进型3IDT-LCR结构的SAW滤波器具备低插入损耗、小矩形系数和高带外抑制的特点。     

Y branching silica waveguide 1*8 splitter module

Silica waveguide Y branching 1*8 splitters were fabricated and found to be highly reliable after housing. The silica waveguide has a splitting excess loss of 0.57 dB. The packaged device has a housing excess loss of 0.89 dB. The measured return loss was over 50 dB above room temperature. The loss deviation under heat cycle testing was 0.46 dB in the temperature range -20-+70 degrees C.<>     

A novel type of waveguide polarizer with large cross-polarbandwidth

A wideband quarter-wave polarizer is presented having a rectangular cross-section, where all four walls are loaded with a dielectric or artificial dielectric. A much larger bandwidth compared to existing polarizers can be obtained without increasing the insertion loss. A polarizer so constructed was fabricated and measured. The polarizer had a differential phase shift within 90°±0.7° corresponding to 44 dB isolation, insertion loss below 0.06 dB, and return loss below -24 dB (VSWR <1.13) over the frequency band 10.95 to 14.50 GHz     

一种小型化射频MEMS电子校准件设计

通过短路-开路-负载-直通(SOLT)校准原理与MEMS开关结合,设计了一种小型化多功能电子校准件.仿真结果表明,在0.1～20 GHz频段内,该电子校准件的双端口校准仅需2步;直通状态插入损耗≤0.9 dB,开路状态回波损耗≤0.48 dB,短路状态回波损耗≤0.39 dB.整体尺寸为2.5 mm×1.2 mm×0....     

Monolithic integrated wavelength demultiplexer based on a waveguideRowland circle grating in InGaAsP/lnP

We present detailed modeling and experimental results for an improved design of an InGaAsP-InP wavelength demultiplexer based on a monolithically integrated Rowland circle grating. The design incorporated ten wavelength channels at 1.55 μm with a uniform spacing of 2 nm. The total on-chip loss was about 10 dB and the crosstalk between adjacent channels was as low as -25 dB. It was shown that low-loss etched turning mirrors can reduce the total on-chip loss by about 4 dB compared to traditional 90° curved multimode waveguides. By replacing standard flat grating facets with retro-reflecting V-shaped facets in the echelle grating, the loss was further reduced by 4 dB. Polarization independent operation within a passband of 0.5 nm was achieved by using multimode output waveguides. The potential sources producing the crosstalk have been analyzed and fabrication modifications for further improvement are suggested     

宽阻带超宽带带通滤波器的设计

针对某些传统滤波器阻带较窄,抑制谐波性能差的缺点,对传统的阶梯阻抗谐振器( SIR)进行了改进,使之通带内回波损耗降低,频带增宽,同时利用缺陷接地结构(DGS)制谐波特性来增加阻带宽度,得到一款低插损滤波器,最后使用HFSS建模仿真.结果表明:该滤波器具有良好的通带效果,通带内插入损耗小于l dB,回波损耗大于10 d...     

SOI基PLC型阵列波导光栅与可调光衰减器单片集成

制作了基于绝缘体上硅(Silicon on Insulator,SOI)材料的8×16通道的阵列波导光栅(Arrayed Waveguide Grating,AWG)与电吸收型可调光衰减器(Variable OpticalAttenuator,VOA)的单片集成器件,其信道间隔为200 GHz.该集成器件采用脊形波导结构,其截面尺寸为亚微米级,整体尺寸为2.9 mm×1 mm.该VMUX器件的片上损耗为9.324～10.048 dB,串扰为6.5～8.2 dB;在20 dB衰减下,单通道最大功耗为87.98 mW;最大信道偏振相关损耗(Polarization Dependent Loss,PDL)为0.461 dB,16通道的衰减一致性为0.245 dB.该器件能够实现良好的波分复用/解复用及信道功率均衡的功能.     

Sub-THz Four-Way Waveguide Power Combiner With Low Insertion Loss

A four-way waveguide power divider has been developed in sub-THz band. The waveguide power divider was achieved with the improved H-plane T-junction structure. By tuning the depth and width at the junction of the waveguide, the input impendence was matched and the two-way output power amplitude and phase were at the same level. The four-way power divider was realized by the concatenation of two same T-junction at the two output ports. A sub-THz four-way passive power combiner is designed, fabricated and measured. The measure results show that the measured insertion loss of the fabricated four-way passive power combiner is less than 1.2 dB whereas the input return loss is greater than 14.8 dB from 97.5 to 101.7 GHz. Experiments on the sub-THz four-way passive power combiner show that a minimum insertion loss of 1 dB has been achieved at about 99.5 GHz. The measured minimum insertion loss of the waveguide power divider is half of the insertion loss for the entire passive power combiner (0.5 dB), which corresponds to a power-combining efficiency of 89 %. The measured results agree with the simulated ones closely.     

Miniature Four-Way and Two-Way 24 GHz Wilkinson Power Dividers in 0.13 μm CMOS

This letter presents 24 GHz four-way and two-way miniature Wilkinson power dividers (PDs) in a standard CMOS technology. The chip area is significantly reduced using a lumped-element design, and the effective areas of four-way and two-way Wilkinson dividers are 0.33 times 0.33 mm² and 0.12 times 0.29 mm², respectively. The four-way Wilkinson divider results in an insertion loss <2.4 dB, an input/output return loss better 15.5 dB, and a port-to-port isolation >24.7 dB from 22 to 26 GHz. The two-way Wilkinson divider results in an insertion loss <1.4 dB, an input/output return loss better 8.9 dB, and a port-to-port isolation >14.8 dB from 22 to 26 GHz. To the author's knowledge, this is the first demonstration of 24 GHz four-way Wilkinson PD in a standard CMOS technology.     

Fused taper/filter hybrid single-mode wavelength divisionmulti/demultiplexer

A low loss and low crosstalk single-mode wavelength division multi/demultiplexer was successfully fabricated by embedding an interference filter in each output arm of a fused taper coupler. The insertion loss was around 1.5 dB at the wavelengths of 1.3 μm and 1.55 μm, and both near-end and far-end crosstalks were less than -50 dB     

Performance of Pr-doped fluoride fibre amplifier for multichannel AM-VSB transmission

The system performance of a Pr-doped fluoride fibre amplifier was examined for multichannel AM-VSB video signal transmission for the first time. For a CNR of 51 dB, a loss budget of 15.1 dB was obtained with the amplifier, and for a CNR of 46 dB, the loss budget was expanded to 20.1 dB.<>     

基于氮化铝技术的表贴型微波封装

采用氮化铝多层布线技术,运用垂直过渡方式实现微波信号从基板底部到表面的信号传输,完成表贴式微波封装设计。在DC-18GHz内,该表贴互连反射损耗小于-15dB,插入损耗小于1.0dB。采用该技术封装了6～18GHz宽带放大器,封装尺寸为5mm×5mm×1.2mm,频带内反射损耗小于-10dB,增益15dB,平坦度小于1dB;另外还封装C波段5W功率放大器,封装尺寸为8mm×8mm×1.2mm,带内增益大于25dB,反射损耗小于-10dB,饱和输出功率37dBm,效率35%。采用技术的表面贴装放大器性能上能够满足微波通信、雷达应用,可用回流焊安装,适合规模生产。     

Measurement of building penetration into medium buildings at 900and 1500 MHz

The propagation loss into ten medium-sized buildings in Schaumburg, IL, has been measured. At 900 MHz, the mean penetration loss in the lower enclosed floors at or near ground level was found to be 10.8 dB with a standard deviation of 5.8 dB. At 1500 MHz, penetration loss was found to be 10.2 dB, and the standard deviation was 5.6 dB. Data was also taken up to 12 floors (with a higher concentration of data on the first five floors) to show higher elevation trends in the penetration loss. The measured building penetration loss was combined with data from other references, and the slope of a best fit curve as a function of frequency is found to be -7.9 dB per decade