A small, low power boost regulator optimized for energy harvesting applications

A small, low power bootstrapped boost regulator is introduced that can start up with an input voltage of 240 mV and achieve a maximum efficiency of 97 %. The proposed circuit uses two separate control schemes for startup and steady-state operation. A fixed-frequency oscillator is used to initially start up the circuit and raise the output voltage. Once the output voltage has reached a level adequate to bias the internal circuitry, a constant-on-time style hysteretic control scheme is used, which helps increase system efficiency compared to using a conventional pulse-width-modulated control scheme. While maintaining a high efficiency, the proposed circuit only requires three external components: two capacitors (input and output) and an inductor. The effectiveness of this approach is shown through Spectre simulation results.     

直管谐振式低频压电声能量回收系统

为了高效回收环境中的声能,基于阵列式压电换能器、直管谐振腔以及能量回收电路提出了一种声能量回收系统.当声波进入直管谐振腔,管中产生谐振驻波作用于压电换能器,将声能转换为电能.本文设计了能量回收电路并且进行理论、仿真分析实验研究了压电振子数量、声波频率、声压级对输出电压的影响,分析了负载电阻对输出电压及功率的影响.实验结果表明,该装置可回收不同频率的声能量,在声波频率为96Hz时发电效果最优.当入射声压级为110dB时,不使用能量回收电路,输出交流电压有效值最高达12.9V,输出交流功率最高达到799μW;使用设计的能量回收电路,最高输出直流电压为64.2V,最高输出直流功率为473μW.该声能量回收系统不仅可以作为声能量采集器,还能对无线传感节点等独立工作的微型电子系统供能.     

电光调制器自适应偏振控制系统设计与实现

为了保持电光调制器(EOM)输入光偏振方向始终与其内部可传播模式偏振方向一致,使EOM获得良好的调制效果,提出了一种基于比例-积分-微分(PID)算法的EOM自适应偏振控制方法,理论分析并实验验证了该方法的可行性。实验结果表明,基于该方法设计的控制系统不仅能实时监测EOM输出光功率,而且能保持其输出光功率最大;与激光器和EOM输入端直接用保偏光纤连接时相比,PID偏振控制下EOM输出平均功率提高了3.08 dB,PD输出电压标准差由0.121 4降至1.237 510-4,稳定控制状态下偏振态矫正时间在ms量级。     

A Method for MPPT Control While Searching for Parameters Corresponding to Weather Conditions for PV Generation Systems

This paper describes a method for maximum power point tracking (MPPT) control while searching for optimal parameters corresponding to weather conditions at that time. The conventional method has problems in that it is impossible to quickly acquire the generation power at the maximum power (MP) point in low solar radiation (irradiation) regions. It is found theoretically and experimentally that the maximum output power and the optimal current, which give this maximum, have a linear relation at a constant temperature. Furthermore, it is also shown that linearity exists between the short-circuit current and the optimal current. MPPT control rules are created based on the findings from solar arrays that can respond at high speeds to variations in irradiation. The proposed MPPT control method sets the output current track on the line that gives the relation between the MP and the optimal current so as to acquire the MP that can be generated at that time by dividing the power and current characteristics into two fields. The method is based on the generated power being a binary function of the output current. Considering the experimental fact that linearity is maintained only at low irradiation below half the maximum irradiation, the proportionality coefficient (voltage coefficient) is compensated for only in regions with more than half the rated optimal current, which correspond to the maximum irradiation. At high irradiation, the voltage coefficient needed to perform the proposed MPPT control is acquired through the hill-climbing method. The effectiveness of the proposed method is verified through experiments under various weather conditions.     

A self-powered piezoelectric energy harvesting interface circuit with efficiency-enhanced P-SSHI rectifier

The key to self-powered technique is initiative to harvest energy from the surrounding environment.Harvesting energy from an ambient vibration source utilizing piezoelectrics emerged as a popular method.Efficient interface circuits become the main limitations of existing energy harvesting techniques.In this paper,an interface circuit for piezoelectric energy harvesting is presented.An active full bridge rectifier is adopted to improve the power efficiency by reducing the conduction loss on the rectifying path.A parallel synchronized switch harvesting on inductor (P-SSHI) technique is used to improve the power extraction capability from piezoelectric harvester,thereby trying to reach the theoretical maximum output power.An intermittent power management unit (IPMU) and an output capacitor-less low drop regulator (LDO) are also introduced.Active diodes (AD) instead of traditional passive ones are used to reduce the voltage loss over the rectifier,which results in a good power efficiency.The IPMU with hysteresis comparator ensures the interface circuit has a large transient output power by limiting the output voltage ranges from 2.2 to 2 V.The design is fabricated in a SMIC 0.18μm CMOS technology.Simulation results show that the flipping efficiency of the P-SSHI circuit is over 80％ with an off-chip inductor value of 820 μH.The output power the proposed rectifier can obtain is 44.4μW,which is 6.7× improvement compared to the maximum output power of a traditional rectifier.Both the active diodes and the P-SSHI help to improve the output power of the proposed rectifier.LDO outputs a voltage of 1.8 V with the maximum 90％ power efficiency.The proposed P-SSHI rectifier interface circuit can be self-powered without the need for additional power supply.     

Stacked-Chip Implementation of On-Chip Buck Converter for Distributed Power Supply System in SiPs

An on-chip buck converter which is implemented by stacking chips and suitable for on-chip distributed power supply systems is proposed. The operation of the converter with 3-D chip stacking is experimentally verified for the first time. The manufactured converter achieves a maximum power efficiency of 62% for an output current of 70 mA and a voltage conversion ratio of 0.7 with a switching frequency of 200 MHz and a 2 times2 mm on-chip LC output filter. The active part and the passive LC output filter are implemented on separate chips fabricated in 0.35-mum CMOS and connected with metal bumps. The use of glass epoxy interposer to increase the maximum power efficiency up to 71.3% is also discussed.     

一种提高垂直腔面发射激光器性能的新工艺

采用一种新的工艺方法提高了垂直腔面发射激光器的输出功率.采用开环分布孔代替环形沟槽,使器件的输出功率提高了0.34倍.14μm孔径的器件输出功率超过10mW,工作电流为29.6mA时,最大输出功率达到12.48mW.而且,这些开环分布孔为电注入提供了便捷的桥通道,很好地解决了电极易过沟断线问题.器件表现了良好的高温工作特性,当温度高达60℃时输出功率仍可达到8mW.     

A predistortion linearizer using envelope-feedback technique withsimplified carrier cancellation scheme for class-A and class-AB poweramplifiers

A predistortion linearization method using an envelope-feedback technique is proposed and implemented in this paper. This linearizer compensates the gain and phase nonlinearity of power amplifier (PA) simultaneously by controlling both variable attenuator and phase shifter with the feedback of only the difference signal between input and output envelopes. A new carrier cancellation scheme composed of a minimization circuit, log detector, and vector modulator is also presented. This circuit achieves adaptive control of the linearizer by enabling direct measurement of out-of-band power. It is well suited to a multichannel system where the allocated channels are time variant. The principle of the proposed linearizer is described and simple AM-AM distortion analysis is presented analytically and graphically based on the conceptual schematic diagram. A two-tone test for a class-A PA at 1.855 GHz with frequency spacing of 1 MHz showed intermodulation-distortion reduction of maximum 16 dB and stable operation over 5-dB output power variation up to 4-dB backoff from the saturation power level. The proposed linearizer is also applicable to class-AB PA's without further special adjustments. The adaptation circuit is fully implemented with analog integrated circuits, which can further extend its applicability with the integration technology     

A 200-mA, 93% peak power efficiency, single-inductor, dual-output DC–DC buck converter

A single-inductor dual-output (SIDO) DC–DC buck converter is presented. The circuit uses only one (external) inductor to provide two independent output voltages ranging from 1.2 V to the power supply (2.6–5 V) with a maximum total output current of 200 mA. The proposed converter has been fabricated in a 0.35-μm p-substrate CMOS technology. Measurement results demonstrate that a peak power efficiency as high as 93.3% can be achieved. An automatic substrate bias switch technique, that cancels the body effect of the p-channel output power transistors, improves the converter power efficiency performance.     

Improved Millimeter Wave Noise Source on BWO

The operation peculiarities and performance of new millimetric noise source on BWO are described. To increase the interaction efficiency and to extend the operation frequency band the modified vane-type slow-wave structure is proposed to use. Packaged K _a-band source provides noise with power spectrum width controlled within 10 - 300 MHz, electronic tunability of the frequency of 10-12% and has the output power up to 18W and electronic efficiency of 5.5%. Electronic tuning of noise frequency has a discontinuities, but the operation frequency band is almost fully covered. To have a possibility to tune the noise power spectrum maximum to the desired frequency both the electronic tuning and mechanical one can be used. Application of the magnet system with focusing magnetic field magnitude up to 4300 G allows to increase output power level and electronic efficiency up to 32 W and 7% respectively.     

Characterization of ion-implanted IMPATT oscillators

Recent experimental results on impact avalanche transit-time diode oscillators fabricated by ion implantation are presented. The technique and problems involved are given. The diodes gave CW X-band power output up to 1.4 watts with efficiencies up to 8 percent. AM sideband noise measurements indicate that the load admittance for minimum noise is not coincidental with that load for maximum power output, and that a reduction of 20 dB in noise may be achieved with a reduction of only 0.5 to 3.0 dB in power output from the maximum power point by the proper choice of the load. AM sideband noise as low as 130 dB below the carrier in a 1-kHz bandwidth and at a sideband of 50 kHz from the carrier has been measured utilizing this technique.     

射频激励“Z”折叠部分波导CO2 激光器研究

文中研究了射频激励“Z”折叠部分波导CO2激光器，比较了普通波导折叠与部分波导折叠的结构特点。采用等效的第二类波导谐振腔，在总增益长度129cm，230W注入功率情况下，获得了最高23．5W的基模激光输出。     

射频激励“Z”折叠部分波导CO2 激光器研究

文中研究了射频激励“Z”折叠部分波导CO2 激光器,比较了普通波导折叠与部分波导 折叠的结构特点。采用等效的第二类波导谐振腔,在总增益长度129cm ,230W 注入功率情况下,获得了最高23. 5W 的基模激光输出。     

A VSWR-protected silicon bipolar RF power amplifier with soft-slope power control

This paper presents the design and measured performance of a 1.8-GHz power amplifier featuring load mismatch protection and soft-slope power control. Load-mismatch-induced breakdown can be avoided by attenuating the RF power to the final stage during overvoltage conditions. This was accomplished by means of a feedback control system, which detects the peak voltage at the output collector node and clamps its value to a given threshold by varying the circuit gain. The issue of output power control has been addressed as well. To this end, a temperature-compensated bias network is proposed, which allows a moderate power control slope (dB/V) to be achieved by varying the circuit quiescent current according to an exponential law. The nonlinear power amplifier was fabricated using a low-cost silicon bipolar process with a 6.4-V breakdown voltage. It delivers a 33.5-dBm saturated output power with 46% maximum power-added efficiency and 36-dB gain at a nominal 3.5-V supply voltage. The device is able to tolerate a 10:1 load standing-wave ratio up to a 5.1-V supply voltage. Power control slope is lower than 80 dB/V between -15 dBm and the saturated output power level.     

局部遮挡条件下的光伏阵列最大功率点跟踪

针对局部遮挡条件下光伏阵列存在多个局部峰值的问题,以准确跟踪到光伏阵列的全局最大功率点为目标,提出一种新型的局部遮挡条件下光伏阵列最大功率点跟踪方法。首先深入分析了局部遮挡条件下的光伏阵列输出特性,并构建了相应的数学模型,然后采用改进扰动观察法搜索到全局最优的光伏阵列最大功率点,防止陷入局部最优点难题,最后采用Matlab 2014仿真软件对其性能进行分析。结果表明,本文方法可以快速、准确找到光伏阵列最大功率点,提高了光伏阵列的输出效率。     

采用实时功率反馈的半导体激光器幅度调制方法

针对现有半导体激光器（Laser Diode,LD）幅度调制电路具有调制幅度不稳定、调制波形存在非线性失真的缺点,提出采用实时功率反馈的幅度调制方法。通过光电二极管（Photodiode,PD）实时监测LD的输出功率,再根据LD的输出功率自动调整LD工作电流,使其输出功率随调制信号线性变化。最后根据提出的调制方法设计并实现了调制电路,实验结果表明:在温度20~40℃范围内,调制电路的-3 dB带宽达到20 MHz,调制功率的幅度稳定度优于4%,最大非线性误差为0.1%。该调制方法提高了半导体激光器的输出功率稳定性,减少了调制波形的非线性失真,拓宽了半导体激光器的线性工作范围。     

A 15 Gbps-NRZ,30 Gbps-PAM4,120 mA laser diode driver implemented in 0.15-an GaAs E-mode pHEMT technology

This paper presents the design and testing of a 15 Gbps non-return-to-zero (NRZ),30 Gbps 4-level pulse amplitude modulation (PAM4) configurable laser diode driver (LDD) implemented in 0.15-μm GaAs E-mode pHEMT technology.The driver bandwidth is enhanced by utilizing cross-coupled neutralization capacitors across the output stage.The output transmission-line back-termination,which absorbs signal reflections from the imperfectly matched load,is performed passively with on-chip 50-Ω resistors.The proposed 30 Gbps PAM4 LDD is implemented by combining two 15 Gbps-NRZ LDDs,as the high and low amplification paths,to generate PAM4 output current signal with levels of 0,40,80,and 120 mA when driving 25-Ω lasers.The high and low amplification paths can be used separately or simultaneously as a 15 Gbps-NRZ LDD.The measurement results show clear output eye diagrams at speeds of up to 15 and 30 Gbps for the NRZ and PAM4 drivers,respectively.At a maximum output current of 120 mA,the driver consumes 1.228 W from a single supply voltage of-5.2 V.The proposed driver shows a high current driving capability with a better output power to power dissipation ratio,which makes it suitable for driving high current distributed feedback (DFB) lasers.The chip occupies a total area of 0.7 × 1.3 mm2.     

单相光伏发电并网的研究

针对如何提高太阳能光伏发电系统的转化效率,对具有最大功率控制的系统进行研究,提出了一种双环控制方式。并以STM32为控制器,给出了其控制方法。通过Matlab建模设计光伏输出后的控制系统,新的控制系统实现了最大功率跟踪与功率因数校正。仿真表明,该方式具有简单、控制方便、效率高的优点。并通过实物加以验证该方法的可行性,该控制策略可应用于单极式光伏并网系统最大功率点跟踪控制,且实现了系统的高效率并网运行。     

W波段功率合成六倍频源

通过倍频方法和功率合成方法设计了W波段六倍频源,将Ku或K波段信号倍频至W波段。信号经过Ka波段二倍频、巴仑、有源放大后,输出两路信号功率约为25 dBm,以此推动变容肖特基二极管进行三倍频,并进行功率合成输出。为了抑制偶次谐波和提高输出功率,二极管使用了反向并联平衡电路结构。该六倍频源在90-115 GHz 输出范围内输出功率大于12 dBm、最大输出功率为13.8 dBm、功率平坦度为1.2 dB。该模块提出了W波段源的产生方法,为今后设计W波段TR组件发射源提供了参考价值。     

Reliability of 1.3 ?m V-grooved inner-stripe laser diodes under high-power operation

Aging tests of 1.3 ?m laser diodes were performed under extremely high power levels up to 85% of the maximum CW output powers. We have verified high reliability under high power levels as high as 75% of the maximum CW output powers at room temperature. The median lifetime is estimated to be 7×104 h at 75% of the maximum CW output power.