A 5.4mW and 6.1% efficiency fixed-tuned 214GHz frequency doubler with Schottky barrier diodes

A Y-band frequency doubler is analyzed and designed with GaAs planar Schottky diode, which is flip-chip solded into a 50 μm thick quartz substrate. Diode embedding impedance is found by full- wave analysis with lumped port to model the nonlinear junction for impedance matching without the need of diode equivalent circuit model. All the matching circuit is designed ＂on-chip＂ and the mul- tiplier is self-biasing. To the doubler, a conversion efficiency of 6.1% and output power of 5.4mW are measured at 214GHz with input power of 88mW, and the typical measured efficiency is 4.5% in 200 - 225 GHz.

The ultimate strength of doubler plate reinforced Y-joints under compression loading

It is common practice in the offshore industry to solve the punching shear problem due to compression by using doubler plate. The finite-element method is a useful tool for studying this problem. The aim of this paper is to study the static strength of doubler plate reinforced Y-joints subjected to compression loading. The finite-element method is adopted in numerical parametric studies. The individual influences of the geometric parameters βand τd （doubler plate to chord wall thickness ratio） and ld/d1（dubler plate length to brace diameter ratio） on the ultimate strength are made clear. The results show the size of plate may have important effects on the strength of reinforced joints. It is found that the ultimate strength of Y-joints reinforced with appropriately proportioned doubler plates can be greatly improved nearly up tothree times to un-reinforced Y-joints.

基于dikson charge pump的voltage doubler设计

随着集成电路工艺的发展,电源电压不断降低,使得charge pump在芯片上的地位更加重要。传统的voltage doubler基于开关的实现方法,由于MOS管阈值电压的影响,使得voltagedoubler的输出电压与2VDD电平相差甚远。在分析dikson charge pump工作原理的基础上,提出了一种新型的基于dikson charge pump的voltage doubler,通过外加电容的方法,可以实现对diksoncharge pump的输出电压进行微调,从而得到所需要的2VDD的电平。采用smic0.35μm工艺仿真后发现当VDD=5V时,传统的voltage doubler输出电平为8.54V,而dikson voltage doubler的输出电平为理想的10V。

Generation of self-oscillations from a singly resonant periodically poled potassium titanyl phosphate crystal frequency doubler

We report on the generation of self-oscillations from a continuously pumped singly resonant frequency doubler based on a periodically poled potassium titanyl phosphate crystal （PPKTP）. The sustained square-wave and staircase curve of self-oscillations are obtained when the incident pump powers are below and above the threshold of subharmonic-pumped parametric oscillation （SPO）, respectively. The self-oscillations can be explained by the competition between the phase shifts induced by cascading nonlinearity and thermal effect, and the influence of fundamental nonlinear phase shift by the generation of SPO. The simulation results are in good agreement with the experiment data.

连续波输出功率111.27 mW的G波段四端口平衡式倍频器

利用新颖的四端口平衡式二倍频原型,开发了215~230 GHz频段的肖特基变容管倍频器,并具备更加优秀的变频效率和功率容量。同时,所提出的倍频架构能够实现奇次谐波和四次谐波的本征抑制,并且其中采用的二极管管结数量相对于传统平衡倍频结构提升了两倍。因此,这种四端口倍频电路可以实现更好的转换效率和双倍的功率处理能力。在室温下,当输入功率为196~340 mW时,该倍频器具有约39.5%的峰值转换效率(@218 GHz),即使在较高的频率下,该倍频器也被证明是高功率太赫兹波信号产生的理想解决方案。

基于改进开关可调电容的宽调谐太赫兹频率源设计

针对太赫兹频率源调谐范围窄的问题,基于普通PMOS可变电容设计了一种改进的开关可调电容,实现了电容变化的单调性,并基于该电容结合衬底调谐方式设计了一种宽调谐范围、高输出功率的压控振荡器(Voltage-controlled oscillator, VCO)。将设计的VCO结合二倍频器实现了一种工作在太赫兹频段的,具有较宽调谐范围及较高输出功率的太赫兹频率源。使用40 nm CMOS工艺设计的太赫兹频率源输出频率为146.3~168.5 GHz,调谐范围14.1%,并同时具有最高1.3 dBm的输出功率,其在10 MHz频偏处的相位噪声最优为-105.52 dBc/Hz。

低纹波空间可调高压电源设计

为了满足空间探测载荷(如质谱仪和能量粒子探测器等)对高压电源输出纹波的要求,设计一款小功率、低纹波、最大输出电压为10 kV的可调高压直流电源。设计中使用罗耶架构的逆变器和倍压整流电路,利用反馈回路,使纹波电压峰峰值小于2 V;使用51系列单片机控制电源输出电压,监测电源的工作状态。除在原理设计方面降低输出电压纹波外,还提出其他降低输出电压纹波的措施。测试结果表明,所设计的高压电源具有输出电压稳定可调、纹波低的特点,可以满足空间探测载荷对高压电源的基本性能要求。

170GHz二倍频器2路功率合成技术研究

文章研究并实现了基于170GHz二倍频器2路的功率合成。采用三维电磁场仿真设计并实现了E面T型功分/功合器。功率分配器采用WR10标准波导,80GHz~95GHz频带内,插入损耗在0.2dB左右,端口2和端口3之间隔离度在6dB左右。输出功率合成器采用WR5标准波导,160GHz~185GHz频带内,插入损耗在0.4dB左右,端口2和端口3之间隔离度在6dB左右。采用GaAs肖特基二极管单片集成技术设计并制备单路二倍频器,以满足一致性要求;基于170GHz二倍频器2路功率合成的测试结果表明,输入功率在600mW~800mW之间,163GHz~178GHz的输出功率在110mW~264mW,合成效率在80%以上。在171GHz的频点下,峰值输出功率可达264mW,峰值合成效率达到92%。

W-band push–push monolithic frequency doubler in 1-μm InP DHBT technology

A W-band frequency doubler MMIC is designed and fabricated using 1-μm InP DHBT technology. Ac tive halun is employed to transform the single-ended signal into differential output. Push-push configuration loaded with harmonic resonant network is utilized to acquire the second harmonic frequency. A multi-stage differential structure improves the conversion gain and suppresses the fundamental frequency. The MMIC occupies an area of 0.55 x 0.5 mm2 with 18 DHBTs integrated. Measurements show that the output power is above 5.8 dBm with the suppression of fundamental frequency below -16 dBc and the conversion Rain above 4.7 dB over 75-80 GHz.

Nanoindentation on the doubler plane of KDP single crystal

The nanohardness is from 1.44 to 2.61 GPa,the Vickers hardness is from 127 to 252 Vickers,and elastic modulus is from 52 to 123 GPa by the nanoindentation experiments on the doubler plane of KDP crystal. An indentation size effect is observed on the doubler plane in the test as the nanohardness and elastic modulus decreases with the increase of the maximum load.Slippage is identified as the major mode of plastic deformation, and pop-in events are attributed to the initiation of slippage.And the variation of unloading curve end is the result of stick effects between the indenter and the contact surface.The depth of the elastic deformation,which is between 40 and 75 nm,is responsible for the elastic deformation.The doubler plane of KDP crystal has anisotropy,and the relative anisotropy of nanohardness is 8.2%and the relative anisotropy of elastic modulus is 8.0%.

Frequency-stabilized semimonolithic frequency doubler with high output power

We present a semimonolithic frequency-doubler from 1080 to 540 nm with 80% doubling efficiency and up to 849-mW output power of green light. A frequency-stabilized laser diode (LD) pumped continuous wave (CW) Nd:YAP laser is used as the pump source of the doubler consisting of an α-cut KTP crystal and an input mirror. The frequency stabilities of the output second harmonic wave are better than ±246 kHz and ±2.3 MHz in 1 and 30 minutes, respectively, and the intensity fluctuation is less than ±0.65%.

Well-balanced ambipolar diketopyrrolopyrrole-based copolymers for OFETs,inverters and frequency doublers

Conjugated polymers with well-balanced ambipolar charge transport is essential for organic circuits at low cost and large area with simplified fabrication techniques.Aiming at this point,herein,a novel asymmetric thiophene/pyridine-flanked diketopyrrolopyrrole-based copolymer(PPyTDPP-2FBT)is designed and synthesized.Due to the effect of incorporating F atoms on molecular energy alignment and conjugation conformation,the PPyTDPP-2FBT copolymer exhibits typical V-shaped ambipolar field-effect transfer characteristics with well-balanced hole and electron mobilities of 0.64 and 0.46 cm^(2)V^(−1)s^(−1),respectively.Furthermore,organic digital and analog circuits such as inverters and frequency doublers are successfully constructed based on solution-processed films of the PPyTDPP-2FBT copolymers which show a typical circuit operating mode with a high gain of 133 due to the well-balanced electrical properties.In addition,PPyTDPP-2FBT-based devices also demonstrate good stability and batch repeatability,suggesting their great potential applications in organic integrated electronic circuits.

A broadband GaAs MMIC frequency doubler on left-handed nonlinear transmission lines

A broadband frequency doubler using left-handed nonlinear transmission lines（LH NLTLs） based on MMIC technology is reported for the first time.The second harmonic generation on LH NLTLs was analyzed theoretically. A four-section LH NLTL which has a layout of 5.4×0.8 mm^2 was fabricated on GaAs semi-insulating substrate. With 20-dBm input power,the doubler obtained 6.33 dBm peak output power at 26.8 GHz with 24-43 GHz—6 dBm bandwidth.The experimental results were quite consistent with the simulated results.The compactness and the broad band characteristics of the circuit make it well suit for GaAs RF/MMIC application.

W-band high output power Schottky diode doublers with quartz substrate

W-band quartz based high output power fix-tuned doublers are analyzed and designed with planar Schot- tky diodes. Full-wave analysis is carried out to find diode embedding impedances with a lumped port to model the nonlinear junction. Passive networks of the circuit, such as the low pass filter, the E-plane waveguide to strip transitions, input and output matching networks, and passive diode parts are analyzed by using electromagnetic simulators, and the different parts are then combined and optimized together. The exported S-parameters of the doubler circuit are used for multiply efficiency analysis. The highest measured output power is 29.5 mW at 80 GHz and higher than 15 mW in 76-94 GHz. The highest measured efficiency is 11.5% at 92.5 GHz, and the typical value is 6.0% in 70-100 GHz.

Design of 20-44 GHz broadband doubler MMIC

This paper presents the design and performance of a broadband millimeter-wave frequency doubler MMIC using active 0.15 μm GaAs PHEMT and operating at output frequencies from 20 to 44 GHz. This chip is composed of a single ended-into differential-out active Balun, balanced FETs in push-push configuration, and a distributed amplifier. The MMIC doubler exhibits more than 4 dB conversion gain with 12 dBm of output power, and the fundamental frequency suppression is typically -20 dBc up to 44 GHz. The MMIC works at VDD = 3.5 V, Vss = -3.5 V, Id = 200 mA and the chip size is 1.5× 1.8 mm^2.

一种高增益耦合电感交错组合Boost-Zeta变换器

为提升Boost变换器的电压增益,本文提出结合耦合电感和倍压单元的交错组合DC-DC变换器。该变换器由Boost和Zeta变换器组合并引入耦合电感倍压技术而得到,并利用无源钳位支路吸收漏感能量,开关管采用交错控制,降低了开关管的电压尖峰,实现开关管低电压应力,在无需极限占空比和高匝比的情况下可获得更高的电压增益。本文深入讨论了所提拓扑的工作原理及特点,对比了不同变换器的电气性能;对实验参数进行设计,最后通过实验对变换器的理论分析进行验证。

High frequency doubling efficiency THz GaAs Schottky barrier diode based on inverted trapezoidal epitaxial cross-section structure

A high-performance terahertz Schottky barrier diode(SBD)with an inverted trapezoidal epitaxial cross-sectional structure featuring high varactor characteristics and reverse breakdown characteristics is reported in this paper.Inductively coupled plasma dry etching and dissolution wet etching are used to define the profile of the epitaxial layer,by which the voltage-dependent variation trend of the thickness of the metal-semiconductor contact depletion layer is modified.The simulation of the inverted trapezoidal epitaxial cross-section SBD is also conducted to explain the physical mechanism of the electric field and space charge region area.Compared with the normal structure,the grading coefficient M increases from 0.47 to 0.52,and the capacitance modulation ratio(C^(max)/C_(min))increases from 6.70 to 7.61.The inverted trapezoidal epitaxial cross-section structure is a promising approach to improve the variable-capacity ratio by eliminating the accumulation of charge at the Schottky electrode edge.A 190 GHz frequency doubler based on the inverted trapezoidal epitaxial cross-section SBD also shows a doubling efficiency of 35%compared to that 30%of a normal SBD.

一种包板加强T型管节点的简化算法

包板在海洋工程结构中有着广泛的应用,限于其复杂的受力特性,对其力学性能一直没有可量化的计算方法。利用有限元分析方法对包板加强的T型管节点,分别在轴向受压﹑轴向受拉和受弯曲工况下的承载能力进行研究,在宽幅值包板极限承载力公式的基础上,结合API RP2A中简单节点的计算方法,给出了可量化的适用于工程实践中的窄幅值包板加强T型节点校核计算公式,并给出包板与弦杆连接角焊缝选择方法。分析结果表明,该简化计算方法能够有效体现出垫板各参数对承载能力的影响,对包板设计起到指导作用,能够有效简化包板设计的计算过程。

340 GHz GaN大功率固态倍频链

随着太赫兹技术的应用和发展,对大功率太赫兹固态源的需求愈加迫切。文中基于GaN肖特基二极管(SBD)工艺设计并制造了具有高功率输出的170 GHz和340 GHz太赫兹倍频器,实现了340 GHz大功率太赫兹固态倍频链。采用多管芯GaN SBD提高器件功率承载能力,综合开展电路优化设计提升倍频性能,通过仿真研究和实验测试,验证了倍频器设计的有效性和先进性。170 GHz倍频器的实测峰值输出功率达到580 mW,倍频效率为14.5%。340 GHz倍频器的实测峰值输出功率为66 mW,倍频效率为12.5%。该太赫兹固态倍频链性能优良,在太赫兹系统中具有重要的应用价值。

基于单片集成电路的180 GHz大功率倍频器

随着工作频率的提升,太赫兹倍频链路对第一级倍频器的输出功率要求越来越高,提升其功率承受能力是解决该问题的主要途径之一。设计并制作出高击穿的氮化镓肖特基势垒二极管,并与砷化镓二极管进行了对比。氮化镓二极管大的电容调制能力弥补了高电阻导致的低效率,使其具有与砷化镓倍频器相当的转换效率。针对传统混合集成电路结构的氮化镓倍频器连续波功率低的问题,研制出基于高热导率碳化硅单片集成电路形式的180 GHz氮化镓大功率倍频器,并与砷化镓倍频器进行了性能对比。在600 mW输入功率下,两种倍频器的转换效率均大于20%,输出功率大于120 mW。氮化镓二极管的高击穿特性和碳化硅衬底的高导热性使得氮化镓倍频器在大功率输入下具有更好的性能。