High-Output, Single- and Dual-Diode, Millimeter-Wave Frequency Doublers

A balanced, dual-diode varactor frequency doubler for 85-116 GHz is described and its performance compared to that of a single-diode device. The balanced doubler can provide a minimum of 18 mW between 85 and 116 GHz for 190-mW maximum safe input power, while the single-diode doubler using the same diode-type exhibits a minimum output power of 10 mW over the same frequency range for a maximum safe input power of 90 mW. An improved single-diode design using a higher break-down voltage diode has achieved a minimum output power of 18 mW between 97 and 116 GHz for a maximum safe input power of 150 mW. These devices have been used in cascade with a frequency tripler to implement a 6X multiplier chain to 310-350 GHz with a minimum output power in this submillimeter band of 0.6 mW.     

High-power output over 200 mW of 1.3 µm GaInAsP VIPS lasers

Maximum CW output power was investigated in GaInAsP 1.3μm V-grooved inner stripe on P-substrate (VIPS) lasers considering both cavity length and facet reflectivity. Long-cavity lasers show a strong dependence of maximum output power on front reflectivity. A CW light output over 200 mW was obtained at room temperature using a 700 μm long cavity laser with 5 and 98 percent reflectivity of the front and rear facets, respectively. The fundamental transverse mode operation was confirmed up to 170 mW. A coupled power over 110 mW into a single-mode fiber was achieved with a coupling efficiency of 58 percent. We have verified the high reliability under high power levels, as high as 75 percent of the maximum CW output powers at room temperature.     

High-power singlemode AlGaInAs/InP 14xx-nm laser for uncooled application

360 mW fibre output power and excellent wavelength stability within 0.6 nm over a temperature range from 10 to 70/spl deg/C in a grating-stabilised AlGalaAs/InP 14xx-nm pump laser is reported. A fibre output power of 300 mW was maintained from 10 to 70/spl deg/C as the driving current was increased by 36% or 1.34 dB.     

一种新的低压直流耦合1.25 Gb/s激光二极管驱动电路

文中提出一种输出结构能克服传统的激光二极管驱动电路在直流耦合方式下不支持低电源电压操作的问题。新的APC能稳定输出平均光功率和消光比分别在0.3dBm和±0.4dB(-40°C~100°C)范围内。此外,快速二分查找算法使APC初始化时间不超过0.6μs,突发开启和突发关断延时小于5ns,满足PON要求。样片采用TSMC0.8μmBiCMOS工艺实现,芯片面积为1.56mm×1.67mm,功耗为105mW。     

Dual-output switched-capacitor DC–DC converter with pseudo-three-phase swap-and-cross control and amplitude modulation mechanism

This paper presents an inductorless dual-output switched-capacitor DC–DC converter employing pseudo-three-phase swap-and-cross control (PTPSCC) and an amplitude modulation mechanism (AMM). The AMM circuit scales the amplitudes of the driving signals for the switches according to the loading conditions in order to minimize switching losses. To reduce output ripples, average charge distribution, and improve regulation, the PTPSCC circuit continuously switches power transistors to deliver enough charge to the outputs by keeping at least one flying capacitor connected to each output. The switched capacitor DC–DC converter was implemented in a standard 0.18-μm 3.3-V CMOS process. Measurements were used to verify that the proposed converter provides dual independently regulated output voltages without cross regulation. The two outputs were regulated at 2.5 and 0.8 V with input ranges of 1.7–2 V. The maximum output loading was 100 mA for both outputs. A power efficiency of 90.5% was achieved at a maximum total output power of 330 mW with a switching frequency of 500 kHz, and a maximum power efficiency of 92.1% was achieved for a total output power of 210 mW. The maximal peak-to-peak output ripple voltages for the two outputs at 100 mA load currents were suppressed to below 26 and 20 mV, respectively.     

A clocked high-pass-filter-based offset cancellation technique for high-gain biomedical amplifiers

In this article, a simple offset cancellation technique based on a clocked high-pass filter with extremely low output offset is presented. The configuration uses the on-resistance of a complementary metal oxide semiconductor (CMOS) transmission gate (X-gate) and tunes the lower 3-dB cut-off frequency with a matched pair of floating capacitors. The results compare favourably with the more complex auto-zeroing and chopper stabilisation techniques of offset cancellation in terms of power dissipation, component count and bandwidth, while reporting inferior output noise performance. The design is suitable for use in biomedical amplifier systems for applications such as ENG-recording. The system is simulated in Spectre Cadence 5.1.41 using 0.6 μm CMOS technology and the total block gain is ～83.0 dB while the phase error is <5°. The power consumption is 10.2 mW and the output offset obtained for an input monotone signal of 5 μVpp is 1.28 μV. The input-referred root mean square noise voltage between 1 and 5 kHz is 26.32 nV/√Hz.     

基于F-P干涉技术的通信波段可调谐激光器

根据F-P干涉原理设计制作了楔型F-P滤波器,使用这种滤波器进行可调谐掺铒光纤激光器实验,980nmLD泵浦功率为25mW时获得了稳定的单纵模激光输出,输出功率约0．6mW,线宽低于0．06nm,在34．2nm波长调谐范围内功率变化不超过0．5dB,边模抑制比大于35dB。     

DC-Coupled Burst-Mode Laser Diode Driver with Automatic Power Control for 1.25Gbit/s PON System

An integrated burst-mode laser diode driver is presented for PON application. The bias current range and modulation current range are 1–75 mA and 5–80 mA respectively. The DC-coupled interface between the driver and the laser diode can tolerate the output transient voltage as low as 0.6v. The novel digital APC loop can stabilize the output average optical power and extinction ratio respectively within ± 0.3 dBm and ± 0.4 dB (−40 to 100^∘C) with less than 0.6 μs initialization time and infinite bias current and modulation current hold time. Moreover, the fast burst response is achieved with burst on/off time less than 5 ns. The chip is implemented in a TSMC 0.35-μm SiGe BiCMOS technology and occupies an area of 1.56 × 1.67 mm² with power consumption of 105 mW from a supply voltage of 2.5 v.     

InP depletion-mode microwave MISFET's

Depletion-mode aligned-gate InP MISFET's with gate lengths of 1.5-1 µm have given output power of 1.26-W/mm gate width and power-added efficiencies of up to 40 percent at 4 GHz. At 12 GHz, 0.75-W/mm gate width with 22-percent power-added efficiency was obtained. At 18 GHz, a power output of 331 mW (0.59 W/mm) with 3.1 dB of gain and 15.7-percent power-added efficiency was measured. An output power of 245 mW (0.44 W/mm) with 3-dB gain and 10.7-percent efficiency was obtained at 20 GHz.     

0.6 μm CMOS分布式放大器设计

采用了国内0.6μm标准CMOS工艺设计实现了一种单片集成的分布式放大器。放大器采用四级级联结构,单元电路采用管联(cascode)结构以提高隔离度。在输入输出端50Ω匹配情况下,测试得到的频带宽度为0.1~4.0 GHz,增益为5.0±1.0 dB,输入输出的回波损耗分别小于-10 dB和-7 dB。在5 V供电下功耗约为110 mW。     

Nonlinear difference-frequency generation in the mid-infrared spectral range in waveguides with a modulated permittivity profile

A method for implementing quasi-phase matching for nonlinear difference-frequency generation in planar waveguides with a modulated permittivity profile is analyzed. For a pump wave power equal to 10 W, the difference-frequency wave power in the 11–24 μm wavelength range can be as high as 0.6 μW for edge output and 0.12 mW/mm² for vertical output.     

An all solid-state 330 GHz frequency multiplying Chain for 664 GHz radiometers application

An all solid-state 330 GHz ×6 × 2 × 2 frequency multiplying chain is constructed and tested and it is used as a local oscillator (LO) in 664 GHz radiometers for cirrus clouds and cloud ice detecting. The frequency multiplying chain consists of a W-band sextupler, followed by a power-combined amplifier which delivers 460–540 mW output power, and two cascaded 165 GHz and 330 GHz balanced frequency doublers. The 165 GHz two-ways power-combined doubler applies four three-anode in series GaAs Schottky diodes to generate 50–63 mW output power in the frequency range 160–176 GHz, and its tested typical efficiency is 11.5%. The cascaded 330 GHz doubler uses a four-anode in anti-series arranged GaAs diode to generate 2.5–4.5 mW output power in the frequency range 320–352 GHz, and its tested typical efficiency is 6.0% and the maximum value is 8.0% at 328 GHz. The output power of the multiplying chain is high enough to pump the 664 GHz heterodyne radiometer for space application.     

VCSELs based on arrays of sub-monolayer InGaAs quantum dots

Vertical-cavity surface-emitting lasers (VCSELs) with an active region based on sub-monolayer InGaAs quantum dots and doped AlGaAs/GaAs distributed Bragg reflectors were grown by MBE. VCSELs with current aperture of 3 μm in diameter demonstrate single-mode lasing in 980-nm range with the threshold current of 0.6 mA, maximum output power up to 4 mW, and external differential efficiency of 68%. Multimode VCSELs with a (10–12)-μm aperture demonstrate ultralow internal optical loss of 0.09% per pass, which compares favorably with the best results obtained in similar lasers with undoped distributed Bragg reflectors. Original Russian Text ? S.A. Blokhin, N.A. Maleev, A.G. Kuz’menkov, Yu. M. Shernyakov, I.I. Novikov, N.Yu. Gordeev, V.V. Dyudelev, G.S. Sokolovskiĭ, V.I. Kuchinskiĭi, M.M. Kulagina, M.V. Maximov, V.M. Ustinov, A.R. Kovsh, S.S. Mikhrin, N.N. Ledentsov, 2006, published in Fizika i Tekhnika Poluprovodnikov, 2006, Vol. 40, No. 5, pp. 633–638.     

A time-domain digitally controlled oscillator composed of a free running ring oscillator and flying-adder

t supply voltages ranging from 0.6 to 1.2 V, and consumes 4 mW of power with 500 MHz frequency output at 1.2 V supply voltage.     

High output power single longitudinal mode graded index separateconfinement multiple quantum well InGaAs/InP distributed feedback (GRINSCH MQW DFB) lasers

A high continuous-wave (CW) output and high quantum efficiency of 1.5 μm-wavelength InGaAs/InP graded-index separate-confinement multiple-quantum-well DFB lasers were demonstrated. A threshold current of 45 mA with a maximum output power close to 100 mW and a quantum efficiency of 0.33 mW/mA was obtained. Single-frequency light output with power as high as 16 dBm (40 mW) was launched into a single-mode fiber     

Wide tuning-range CMOS VCO based on a tunable active inductor

In this paper, a wide tuning-range CMOS voltage-controlled oscillator (VCO) with high output power using an active inductor circuit is presented. In this VCO design, the coarse frequency is achieved by tuning the integrated active inductor. The circuit has been simulated using a 0.18-µm CMOS fabrication process and presents output frequency range from 100 MHz to 2.5 GHz, resulting in a tuning range of 96%. The phase noise is –85 dBc/Hz at a 1 MHz frequency offset. The output power is from –3 dBm at 2.55 GHz to +14 dBm at 167 MHz. The active inductor power dissipation is 6.5 mW and the total power consumption is 16.27 mW when operating on a 1.8 V supply voltage. By comparing this active inductor architecture VCO with general VCO topology, the result shows that this topology, which employs the proposed active inductor, produces a better performance.     

Gigabit logic operation with enhancement-mode GaAs MESFET IC's

Enhancement-mode GaAs MESFET IC's have been fabricated using electron-beam lithography. A recessed-gate structure to reduce the gate-to-source resistance and an air-bridge overlay interconnect to reduce stray capacitance were employed. A 30-ps delay time with an associated power dissipation of 1.9 mW is obtained with a 0.6 × 20-µm gate GaAs MESFET, which is the highest speed among the GaAs FET logics. Divide-by-eight counter has exhibited a 3.8-GHz maximum clock frequency with a power dissipation of 1.2 mW/gate.     

Low-threshold, high-temperature operation of 1.2 μm InGaAsvertical cavity lasers

The growth and characterisation of high performance InGaAs/GaAs quantum-well vertical cavity lasers with an emission wavelength of 1215 nm is reported. Continuous wave operation is demonstrated up to 105°C with a threshold current below 1 mA for T<80°C. For a 2.5 μm device the room temperature threshold current, output power and slope efficiency is 0.6 mA, 0.6 mW and 0.2 W/A, respectively     

0.2 THz二倍频器研究

基于六阳极结反向串联型GaAs平面肖特基二极管,设计并实现了0.2 THz大功率二倍频器。肖特基二极管倒装焊接在50m石英电路上。采用电磁场和电路联合设计仿真获得了二倍频器的倍频效率。当入射功率在100 mW时,输出频率在190~225 GHz带内效率大于5%。在小功率（Pin100 mW）和大功率（Pin300 mW）注入条件下,测试了倍频电路的输出功率和倍频效率。在100 mW驱动功率下采用自偏压测试,最大输出功率为14.5 mW@193 GHz,对应倍频效率为14%;在300 mW驱动功率下采用自偏压测试,在188~195 GHz,输出功率大于10 mW,最大输出功率为35 mW@192.8 GHz,对应倍频效率为11%。     

一种基于自偏置技术的低抖动锁相环

设计了一种环路带宽与输入频率的比值固定的自偏置锁相环。对VCO延迟单元进行改进,降低了抖动。采用SMIC 65 nm CMOS工艺,在1.2 V的工作电压下对锁相环进行仿真,输出频率范围为0.5~3.125 GHz。仿真结果表明,在输出频率1.875 GHz处的峰峰值抖动为8.7 ps,电路的核心功耗为45 mW,相位噪声为-79.7 dBc/Hz。