A 2×2 SOI mach-zehnder thermo-optical switch based on strongly guided paired multimode interference couplers

A silicon-on-insulator 2×2 Mach-Zehnder thermo-optical switch is developed based on strongly guided paired multi-mode interference couplers. The multimode-interference couplers were etched deeply for improving coupler characteristicssuch as self-imaging quality, uniformity and fabrication tolerance. The proposed switch achieves good performances,including a low insertion loss of –11.0dB, a fiber-waveguide coupling loss of –4.3dB and a fast response speed measuredto be 3.5 and 8.8 μs for raise and fall switching time, respectively.     

A novel loss compensation technique analysis and design for 60 GHz CMOS SPDT switch

A novel loss compensation technique for a series-shunt single-pole double-throw (SPDT) switch is presented operating in the 60 GHz. The feed-forward compensation network which is composed of an NMOS, a couple capacitance and a shunt inductance can reduce the impact of the feed forward capacitance to reduce the insertion loss and improve the isolation of the SPDT switch. The measured insertion loss and isolation characteristics of the switch somewhat deviating from the 60 GHz are analyzed revealing that the inaccuracy of the MOS model can greatly degrade the performance of the switch. The switch is implemented in TSMC 90-nm CMOS process and exhibits an isolation of above 27 dB at transmitter mode, and the insertion loss of 1.8-3 dB at 30-65 GHz by layout simulation. The measured insertion loss is 2.45 dB at 52 GHz and keeps<4 dB at 30-64 GHz. The measured isolation is better than 25 dB at 30-64 GHz and the measured return loss is better than 10 dB at 30-65 GHz. A measured input 1 dB gain compression point of the switch is 13 dBm at 52 GHz and 15 dBm at 60 GHz. The simulated switching speed with rise time and fall time are 720 and 520 ps, respectively. The active chip size of the proposed switch is 0.5×0.95 mm².     

基于手机应用的集成无源器件滤波器的线性180纳米绝缘体硅天线开关模组

A broadband monolithic linear single pole, eight throw （SP8T） switch has been fabricated in 180 nm thin film silicon-on-insulator （SOI） CMOS technology with a quad-band GSM harmonic filter in integrated passive devices （IPD） technology, which is developed for cellular applications. The antenna switch module （ASM） features 1.2 dB insertion loss with filter on 2G bands and 0.4 dB insertion loss in 3G bands, less than -45 dB isolation and maximum -103 dB intermodulation distortion for mobile front ends by applying distributed architecture and adaptive supply voltage generator.     

A DESIGN OF 0.25μm CMOS SWITCH

Single-Pole Double-Throw （SPDT） broadband switch has been designed in a 0.25gm Complementary Metal Oxide Semiconductor （CMOS） process. To optimize the performance of isolation and insertion loss, based on normal design, the effects of Gate Series Resistances （GSR） on insertion loss and switching time are analyzed for the first time. The compatible GSRs are chosen by the analyses. The fabricated chips were tested and the results show the switch isolation from DC （Direct Current） to 1GHz exhibits 55dB and insertion loss lower than 2.1 dB.     

Design of a 24–40 GHz balanced low noise amplifier using Lange couplers

A wide band （24–40 GHz） fully integrated balanced low noise amplifier （LNA） using Lange couplers was designed and fabricated with a 0.15 μm pseudomorphic HEMT （pHEMT） technology. A new method to design a low-loss and high-coupling Lange coupler for wide band application in microwave frequency was also presented. This Lange coupler has a minimum loss of 0.09 dB and a maximum loss of 0.2 dB over the bandwidth from 20 to 45 GHz. The measured results show that the realized four-stage balanced LNA using this Lange coupler exhibites a noise figure （NF） of less than 2.7 dB and the maximum gain of 30 dB; moreover, a noticeably improved reflection performance is achieved. The input VSWR and the output VSWR are respectively less than 1.45 and 1.35 dB across the 24–40 GHz frequency range.     

Capacitive Microwave MEMS Switch

A novel capacitive microwave MEMS switch with a silicon/metal/dielectric as a membrane is fabricated successfully by bonding and etching-stop process.Its principal,design,and fabricating process are described in detail.A patterned dielectric layer,Ta2O5,with dielectric constant of 24 is reached.Experiment results show this novel structure,where the switch’s dielectric layer is not prepared on the transmission line,features very low insertion loss.The insertion loss is 0.06dB at 2GHz and lower than 0.5dB in the wider range from DC up to 20GHz,especially when the transmission line metal is only 0.5μm thick.     

基于砷化镓工艺的集成式功分器

A compact lumped integrated power divider with low insertion loss using 0.5 μm GaAs pHEMT technology is presented. The proposed power divider uses the π-type LC network for transmission line equivalence and a thin film resistor for isolation tuning simultaneously. The quality factor of the inductor is analyzed and synthesized for insertion-loss influence. The measured insertion loss is less than 0.5 dB when the operating frequency is within the range of 5.15-6.15 GHz. The return loss and isolation are better than 15 dB and 20 dB, respectively. The compact dimension of the power divider is as small as 0.9 × 0.85 mm^2. The measured results agree well with the simulated ones.     

一种QFN24封装的适用于0.5GHz-3GHz应用的4X2矩阵开关

This paper presents a 4×2 switching matrix implemented in the Win 0.5 m Ga As pseudomorphic high electron mobility transistor process, it covers the 0.5–3 GHz frequency range. The switch matrix is composed of 4 SPDT switch whose two output ports can simultaneously select the input port and a 4 to 8 bit digital decoder,both the radio frequency(RF) part and the digital part are integrated into one single chip. The chip is packaged in a low cost QFN24 plastic package. On chip shunt, capacitors at the input ports are taken to compensate for the bonding wire inductance effect. The designed switch matrix shows a good measured performance: the insertion loss is less than 5.5 d B, the isolation is no worse than 30 d B, the return loss of input ports and output ports is better than –10 d B, the input 1 d B compression point is better than 25.6 d Bm, and the OIP3 is better than 37 d Bm. The chip size of the switch matrix is only 1.45×1.45 mm2.     

New Type of Y—junction Hybrid Polymer Wavequide Couplers

Optical couplers are the key components for signal distribution in optoelectronic transmitters and receivers.A new low-loss, large-angle Y-junction hybrid polymer optical coupler with an integrated microprism has been fabricated and demonstrated experimentally for use in a mixed-signal module environment.The results show that the radiation loss is small with relatively wide branching angle as compared to a conventional Y-junction coupler.     

Optimization of silicon-on-insulator based optical switch using tapered waveguides

Optimized 2×2 switches based on silicon-on-insulator (SOI) were demonstrated. In the design, single mode rib waveguidesand multimode interferences (MMIs) are connected by tapered waveguides to reduce the mode coupling loss between thetwo types of waveguides. The average insertion loss of the switches is about -16.9 dB and the excess loss of one is measuredof -1.3 dB. The worst crosstalk is larger than 25 dB. Experimental results indicate that some of the main characteristics ofoptical switches are improved in the modified design, which is according with theoretic analysis. The novel design can beused to improve the characteristics of optical switch matrixes based on 2×2 switch units.     

Design and fabrication of sub-μs silicon-on-insulator thermo-optic 4×4 switch matrix

A rearrangeable nonblocking silicon-on-insulator-based thermo-optic 4x4 switch matrix with spot size converters （SSCs） and a new driving circuit are designed and fabricated. The introduction of a spot size converter （SSC） has decreased the insertion loss to less than 10dB and the new driving circuit has improved the response speed to less than l~s.     

Thermo-optically tunable arrayed-waveguide-grating made of polymer/Si

Inthe future,optical communication systems will usemore exceptional optical fiber with high bandwidth.Dense wavelength division multiplexing(DWDM)isconsidered as a promising solution to the demand fortransportingterabits ofinformation viafibers[1].Arrayed…     

Narrow-channel-spacing 32-channel AWG multiplexer with an innovative alignment method

A 32-channel 50 GHz spaced arrayed-waveguide grating（AWG） with our innovative configuration has been designed and fabricated. The performance of the device has been fully tested by using a system that consists of a tunable laser light source （TLS）, an optical power meter and a polarization controller. The insertion loss （IS） of the device is 4.2-7.4 dB. The crosstalk is about - 28 dB. The IS uniformity is less than 3.3 dB. With our configuration,the performance of the device has been enhanced effectively and the difficulty in alignment process has been decreased obviously.     

A 4th order fully integrated active RC complex filter with novel automatic tuning systems

This letter introduces a 4th order active RC complex filter with 1.5MHz center frequency and 1MHz bandwidth. The total harmonic distortion of the filter is less than –60dB and the image rejection ratio is greater than 60dB. A novel technique is also proposed in this letter to automatically adjust the variation of the time constant. The advantages of the proposed method are its high precision and simplicity. Using 5bits control words, the tuning error is less than ±1.6%.     

Silica-based 71-channel arrayed waveguide grating

With the rapid increase of global information capaci-ty,all optical wavelength division multiplexing(WDM)networks are very attractive because they are capable ofprocessing broadband optical signals without convertingthem to electronic signals.Large channe…     

Flat-top silica-based arrayed waveguide grating with 40-channels

A wavelength multiplexer or demultiplexer plays ani mportant role in all wavelength division multiplexing( WDM) system.Silica-basedarrayed waveguide gratings(AWGs) offer attractive featuresinthis area due to theadvantage of large output channels and lowlo…     

Analysis of electro-optic switches with series-coupled multiple microring resonators

In terms of the coupled mode theory, microring resonance and electro-optic modulation princeple, a reasonable project is proposed for designing an electro-optic switch with the series-coupled multiple microring resonators. The simulation and optimization are performed at the resonant wavelength of 1550 nm. The results are as follows: the core size of the microring is 1.6 μm×1.6 μm, the confined layer between the core and the electrode is 1.6 μm, the thickness of the electrode is 0.15 μm, the radius of the m...     

A low voltage CMOS RF front-end for IEEE 802.11b WLAN transceiver

A low voltage CMOS RF front-end for IEEE 802.11b WLAN transceiver is presented. The problems to implement the low voltage design and the on-chip input/output impedance matching are considered, and some improved circuits are presented to overcome the problems. Especially, a single-end input, differential output double balanced mixer with an on-chip bias loop is analyzed in detail to show its advantages over other mixers. The transceiver RF front-end has been implemented in 0.18 um CMOS process, the measured results show that the Rx front-end achieves 5.23 dB noise figure, 12.7 dB power gain (50 ohm load), −18 dBm input 1 dB compression point (ICP) and −7 dBm IIP3, and the Tx front-end could output +2.1 dBm power into 50 ohm load with 23.8 dB power gain. The transceiver RF front-end draws 13.6 mA current from a supply voltage of 1.8 V in receive mode and 27.6 mA current in transmit mode. The transceiver RF front-end could satisfy the performance requirements of IEEE802.11b WLAN standard. Supported by the National Natural Science Foundation of China, No. 90407006 and No. 60475018.     

Electron effective mass in InuGa1−uPvAs1−v for 0 ≤ v ≤ 1

The electron effective mass in In_uGa_1−uP_vAs_1−v has been measured on seven samples lattice-matched to InP and evenly spaced in values of v between 0 and 1, using the temperature dependence of the amplitude of the Shubnikov-de Haas oscillations at high magnetic fields. Values of the carrier concentrations, Hall mobilities and Dingle temperatures measured on these samples are also reported. Work sponsored in part by the National Science Foundation, Grant No. ENG 76-09586, and in part by International Telephone and Telegraph Electro-Optical Products Division. Work done in part at the M.I.T. Francis Bitter National Magnet Laboratory. Funded in part by the National Science Foundation under Grant No. DMR-76-80895.     

An enhanced detection algorithm for V-BLAST system

I. Introduction It has shown that the use of Multi-Input Multi- Output (MIMO) can provide extraordinarily high spectral efficiencies in rich-scattering environment[1 In V-BLAST architecture[2,3] the streams of inde- pendent data are transmitted over different antennas thus maximizing the average data rate. The origina V-BLAST algorithm uses the iterative nulling and Decision Feedback Equalization (DFE) in decoding process, a relatively simple approach which can also result in error …