A high-speed low-voltage double-switch optical crossconnect using stress-induced bending micromirrors

A high-speed low-voltage double-switch electrostatically actuated optical crossconnect (OXC) is demonstrated using stress-induced bending micromirrors. A curved polysilicon seesaw structure substantially lowers the electrostatic operating voltage of the OXC and provides a double-switch option. Large mirror deflection angles of 13/spl deg/ (mirror elevation of 290 /spl mu/m high) and 5/spl deg/ (cantilever deflection of 90 /spl mu/m high), corresponding to low operating voltages of 25 and 18 V, could be obtained. A submillisecond switching time (<850 /spl mu/s), a low optical insertion loss (0.65 dB), and a small polarization-dependent loss (<0.08 dB) are achieved.     

Polarization-insensitive InP-based MQW digital optical switch

A polarization-insensitive InP-based p-i-n multiple-quantum-well switch is demonstrated for the first time. Polarization-insensitive switching and loss are achieved. Crosstalk and loss measurements across a wavelength range of 20 nm centered at 1.55 μm are reported. A crosstalk of better than -13 dB is achieved for both TE and TM polarizations across the 1.54-1.56-μm wavelength range with a switching voltage of -7 V. A low on-chip loss of less than 3 dB is achieved for both TE and TM across the above wavelength range, with a compact switch structure which is 3 mm long     

A 2×2 crosspoint switch fabricated on the passive activeresonant coupler (PARC) platform

We demonstrate the fabrication of a 2×2 crosspoint switch monolithically fabricated on the passive active resonant coupler (PARC) platform by utilizing vertical resonant coupling over a taper between an active and a passive waveguide. The coupling taper was 100 μm long with less than 0.15 dB coupling loss. By pushing the mode up and down as and when required, we are able to integrate passive waveguides and electroabsorption modulators on one chip. The static performance of the switch has been tested, and a modulation depth of 30 dB has been achieved at the wavelength of 1.57 μm for an applied bias of 2.5 V     

A high-speed 4×4 Ti:LiNbO3 integrated optic switchat 1.5 μm

The operation of a fully packaged and pigtailed polarization dependent Ti:LiNbO₃ 4×4 integrated optic switch with an operating wavelength of 1.5 μm is demonstrated. The switching matrix is fast, with a measured 3-dB small-signal bandwidth greater than 1 GHz. Unwanted cross modulation between channels due to coupling between switching elements was measured and found to be less than -20 dB of the signal strength. The switch is composed of balanced bridge switching elements having a 17-V switching voltage, an 18 dB extinction ratio, and an excess optical loss of 0.6 dB     

Reflection-type optical waveguide switch with bow-tie electrode

Based on the total internal reflection and the plasma dispersion effect of SiGe alloy, an intersectional rib optical waveguide switch with bow-tie electrode has been proposed and fabricated for operating wavelengths of 1.3 and 1.55 μm. The thickness of the SiGe layer is 2.6 μm and the width is 9 μm. The branch angle of the switch is 2° and the bow-tie angle is 1.5°. The crosstalks are -19.6 dB for 1.3 μm and -21.8 dB for 1.55 μm. At both wavelengths, the extinction ratio is larger than 38.5 dB and the insertion loss is less than 1.70 dB. The switching time is about 180 ns     

射频微机械CPW开关的研究

本文采用聚酰亚胺牺牲层技术和二氧化硅介质隔离技术,成功地在绝缘多晶硅衬底上研制出一种射频微机械CPW开关.初步测试结果如下:开态电容为0.21pF,关态电容为6.1pF,致动电压为22V,关态下的隔离度为35dB,开态下插入损耗为3dB.该工艺完全与硅基IC工艺兼容,这为射频微机械CPW开关与IC实现单片集成化,降低体积提高可靠性打下了基础.     

High-isolation CPW MEMS shunt switches. 2. Design

For pt.1 see ibid., vol.48, no.6, p.1045-1052 (2000). In this paper, the second of two parts, the equivalent RLC model of the shunt switch is used in the design of tuned two- and four-bridge “cross” switches from 10 to 40 GHz. The cross switch attained an insertion loss of less than 0.3-0.6 dB, a return loss below -20 dB from 22 to 38 GHz in the up state, and a down-state isolation of 45-50 dB with only 1.5 pF of down-state capacitance (C_d). Also, an X-band microelectromechanical system (MEMS) switch with an insertion loss of less than 0.2 dB and an isolation of 35 dB is presented. This is done by inductively tuning the LC series resonance of the shunt switch. The MEMS bridge height is 1.5-2.5 μm, resulting in a pull-down voltage of 15-25 V. Application areas are in low-loss high-isolation communication and radar     

Free-space fiber-optic switches based on MEMS vertical torsionmirrors

This paper reports on the design, fabrication, and performance of a novel MEMS (micro-electro-mechanical-system) fiber-optic switch based on surface-micromachined vertical torsion mirrors. The vertical torsion mirror itself can be used as a 1×2 or an ON-OFF switch. A 2×2 MEMS fiber-optic switch with four vertical torsion mirrors has also been fabricated. The switching voltage is measured to be 80 V for switching angles of 45°. We have achieved a switching time of less than 400 μs (fall time) and an optical insertion loss of 1.25 dB for single-mode fibers. In addition, a bulk-micromachined silicon submount has been developed to package the switch with microball lenses and multimode fibers with passive alignment. With the micromachined switch chip and the hybrid-packaging scheme, the size, weight, and potentially the cost of the fiber-optic switches can be dramatically reduced     

1 × 2 MOEMS switch based on silicon-on-insulator andpolymeric waveguides

A new planar optical switch concept based on a silicon-on-insulator microelectromechanical system (MEMS) structure with post-processed polymeric waveguides is reported. The actuation voltage is 20 to 50 V, and the switching time as low as 30 μs. A crosstalk of -32 dB has been measured     

The SCC BJT: a high-performance bipolar transistor compatible withhigh-density deep-submicrometer BiCMOS SRAM technologies

We present the process development and device characterization of the Selectively Compensated Collector (SCC) BJT specifically designed for high-density deep-submicrometer BiCMOS SRAM technologies. This double-poly BJT takes advantage of the self-aligned polysilicon layers of the SRAM bit cell to obtain high performance without adding excessive process complexity. Furthermore, although an NPN device, the SCC BJT is formed in a lightly doped p-well in which the collector is formed with a single 370 keV phosphorus implant to minimize parasitic junction capacitances without the use of trench isolation or recessed oxides. The suitability of this bipolar structure outside of its original FSRAM intent is proven with its potential for bipolar logic and mixed-mode RF applications. ECL delays of 50 ps at 200 μA and a CML power-delay product of 4.5 fJ at 1.1 V supply were obtained. A 900 MHz noise figure as low as 0.54 dB at 0.5 mA with an associated gain of 14.7 dB was demonstrated as well as a dual modulus ÷4/5 prescaler operating up to 3.3 GHz for a switch current of 200 μA     

Optimisation of LiNbO/sub 3/ BOA waveguide switches operating at 1.3 mu m

The optimisation of X-cut LiNbO/sub 3/ BOA switches for low voltage, low insertion loss operation is described. An LiNbO/sub 3/ waveguide switch operating at 1.3 mu m with an insertion loss of 4.3 dB, switching voltage of 4.7 V and extinction ratio of 21 dB is reported.<>     

2×2 optical waveguide switch with bow-tie electrode based oncarrier-injection total internal reflection in SiGe alloy

Based on the total internal reflection and the plasma dispersion effect of SiGe alloy, a 2×2 intersectional rib optical waveguide switch with bow-tie electrode has been proposed and fabricated for the wavelength of 1.3-μm operation. The thickness of the SiGe layer is 2.6 μm and the width is 9 μm. The branch angle of the switch is 2° and the bow-tie angle is 1.5°. The on-state crosstalk is -19.6 dB, the off-state extinction ratio is 38.5 dB and the off-state insertion loss is less than 1.70 dB. The switching time is about 180 ns     

Polarisation-independent LiNbO3 4×4 matrix switch

The first polarisation independent LiNbO₃ strictly non-blocking 4×4 matrix switch has been developed. This matrix switch has a 4-6 dB insertion loss at any incident polarisation with 1.3 μm wavelength and about 30 V switching voltage     

High power DPDT antenna switch MMIC for digital cellular systems

In this paper, we propose two new types of dual-pole double-throw (DPDT) switch GaAs JFET monolithic microwave integrated circuits (MMICs) for digital cellular handsets. These ICs have the excellent characteristics of low insertion loss and high power handling capability, even with a low control voltage by stacking three JFETs with shallow V_p and using a novel bias circuit using p-n junction diodes. One DPDT switch IC has two shunt FET blocks and can achieve high isolation without external parts. An insertion loss less than 0.6 dB and isolation over 25 dB up to 2 GHz were achieved. P_1dB was about 35 dBm even with a control voltage of 0/3 V. Another DPDT switch IC utilizes parallel resonance of external inductors and parasitic capacitance between the drain and the source of the OFF-state FETs. By attaching 15 nH inductors, for example, the IC exhibited an insertion loss as low as 0.4 dB, an isolation of better than 40 dB at 1.5 GHz, a bandwidth of about 400 MHz for 20 dB isolation, and P_1dB of about 34 dBm with the 0/3 V control     

A 23-ns 4-Mb CMOS SRAM with 0.2-μA standby current

A 4-Mb CMOS SRAM having 0.2-μA standby current at a supply voltage of 3 V has been developed. Current-mirror/PMOS cross-coupled cascade sense-amplifier circuits have achieved the fast address access time of 23 ns. A new noise-immune data-latch circuit has attained power-reduction characteristics at a low operating cycle time without access delay. A 0.5-μm CMOS, four-level poly, two-level metal technology with a polysilicon PMOS load memory cell, yielded a small cell area of 17 μm² and the very small standby current. A quadruple-array, word-decoder architecture allowed a small chip area of 122 mm²     

High threshold uniformity, millimeter-wavep+-GaInAs/n-AlInAs/GaInAs JHEMTs

High threshold voltage uniformity p⁺-GaInAs/n-AlInAs/GaInAs millimeter-wave junction-modulated HEMT's are reported. Devices with 0.2 μm gatelength exhibit a standard deviation in threshold voltage of 13.7 mV across a 1×1.5 in² wafer. The uniformity is achieved in devices which exhibit high DC transconductance (520 mS/mm), high unity-gain cut-off frequencies: f_T (105 GHz) and f_max (exceeding 200 GHz), and low minimum noise figure (0.45 dB) with high associated gain (14.5 dB) at 12 GHz     

Rearrangeably nonblocking 8×8 guided wave optical switch

The design and construction of a lithium niobate 8×8 optical switch with a rearrangeably nonblocking architecture is described. The design is compared with the more familiar strictly nonblocking architecture. The switch has 28 elements, a switching voltage of 26 V and a loss of 5.5 dB at 1.3 μm wavelength     

Ti:LiNbO3 interferometric activated X-switch forhigh-speed applications: IAX

High-speed switching is accomplished by using a balanced bridge interferometric switch with X-switches as electro-optic tunable 3 dB couplers. A device with a 3-dB bandwidth of 6·5 GHz at a switching voltage of 7·0 V and an insertion loss of 4 dB has been realised for λ=1·3 μm     

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     

2 GHz controlled current conveyor in standard 0.8 μm BiCMOStechnology

A new controlled current conveyor operating in class A and implemented using a low-cost industrial BiCMOS 0.8 μm process is described. Its electrical characteristics (voltage and current transfers, parasitic impedances) have been measured. With a bias current of 500 μA and supplied under ±2.2 V, the measurement results show that the circuit exhibits very large -3 dB bandwidths: from DC to 4.5 GHz for the voltage transfer (between Y and X) and from DC to 2 GHz for the current transfer (between X and Z)