用于雷达接收机检测的平面固态噪声源

设计了集成固态噪声源以测得雷达接收机的增益和噪声系数。设计采用国产噪声二极管开发平面集成固态噪声源用于接收机性能检测,包括噪声二极管集成、耦合器、驱动开关电路等。研究了平面集成固态噪声源超噪比(ENR)的测量方法,以及接收机噪声系数和增益的计算公式。固态噪声源和接收机电路无缝集成,极大减小了体积质量。设计的噪声源实现了28 dB的超噪比,较好地满足了接收机的检测要求,自检误差在可接受范围内。本设计通过了各类环境试验,并在实际产品中得到应用,取得较好的效果。     

3mm肖特基势垒二极管雪崩噪声源

介绍了3mm波段肖特基势垒二极管雪崩噪声源,其宽带超噪声比为10.5dB,它与反向电流呈线性关系。     

长波长光纤系统的改进型雪崩光电二极管

本文评述了长波长光纤系统的改进型Ge雪崩光电二极管(Ge-APD)和InGaAs/InP雪崩光电二极管(InGaAs/InP-APD)。P~ -n型和n~ -n-p~ 型锗雪崩光电二极管在1.0～1.5μm波长区比通常的n~ -p型Ge-APD的倍增噪声低。吸收区和倍增区分开的InGaAs/InP—APD在1.0～1.6μm波长区比Ge—APD有较低的暗电流和较低的倍增噪声。这种雪崩光电二极管与Ge雪崩光电二极管相比能改进3～4dB的最小可探测功率。     

雪崩光电二极管最佳工作点的确定

本文根据雪崩管的倍增噪声特性,给出在最佳工作状态下,雪崩光电二极管的倍增噪声电流谱密度与放大器的等效输入噪声电流谱密度之间的数量关系,提出按照放大器本身的噪声电压在输出总噪声电压中所占的比例来确定雪崩光电二极管的最佳工作点的方法。用这种方法确定了厚耗尽层雪崩光电二极管的工作点,用该雪崩光电二级管作激光测距仪的探测器时,使测距仪的测程比用Pin硅光电二极管时提高一倍以上,接收灵敏度提高约二十八倍。     

雪崩光电二极管在激光测距机中的应用

本文根据雪崩光电二极管的噪声特性．提出了按照噪声分配原则来确定雪崩光电二极管最佳工作点的方法。对放大器，接收光路设计和雪崩管的偏压电源等问题均进行了讨论。实验表明应用APD-1型雪崩光电二扳管，使激光测距系统的测程比用pin硅光电二极管时增加一倍以上，接收灵敏度提高27～15倍。     

Ⅲ—v族合金异质结高速雪崩光电二极管

使用GaAlAs/GaAs,GaAlSb/GaSb,GaAlAsSb/GaAseSb和InGaAsP/InP等几种Ⅲ—v族合金系已成功地制成了异质结雪崩光电二极管·这些二极管复盖电光波长从0.4um到1.8um,早期发展阶段显示出令人鼓舞的结果,并得出小于35ps的高速响应和大于95%的高量子效率。本文还将对暗电流和过分的雪崩噪声进行讨论,并对GaAlSb,GaAlAsSb和InGaAsP雪崩光电二极管直接进行比较·     

激光测距应用中雪崩光电二极管最佳工作状态的再研究

回顾了雪崩光电二极管最佳工作状态的确定方法。根据R.J.McIntyre给出的关于达通型雪崩光电二极管的噪声谱密度结果,分析了不同背景下,确定最佳工作状态的最佳噪声分配比的特性,并给出了实验结果。给出了不但能确定和保持雪崩光电二极管的最佳工作状态,而且可以保持恒定的虚警率的实用方法。     

红外探测用球形雪崩二极管

本文介绍硅和硅-锗混合晶体的球形雪崩二极管的探测特性。二极管是在自持雪崩放电区内工作的。所以通过计算自持雪崩而测定光子通量。硅雪崩二极管的光谱响应范围为0.5～1.2微米;异质结雪崩二极管的光谱响应为0.5～1.5微米。当速率计的时间常数为10秒时,在室温下、波长λ=0.75微米时,噪声等效功率NEP=4×10~(-18)瓦,而λ=1.35微米时,NEP=3×10~(-12)瓦。相应的探测率分别为:D＊=9·10~(13)“厘米·秒~(1/2)瓦~(-1)及D*=1·10~8厘米·秒~(-1/2)瓦~(-1)。通过冷却二极管到-30℃,NEP值将下降,D*值将提高10倍。     

激光测距应用中雪崩光电二极管最佳工作状态的再研究

回顾了雪崩光电二极管最佳工作状态的确定方法。根据 R.J.McIntyre给出的关于达通型雪崩光电二极管的噪声谱密度结果,分析了不同背景下,确定最佳工作状态的最佳噪声分配比的特性,并给出了实验结果。给出了不但能确定和保持雪崩光电二极管的最佳工作状态,而且可以保持恒定的虚警率的实用方法。     

采用扩散技术制造的高倍增增益In_(0.53)Ga_(0.47)As/InP异质结构雪崩光电二极管(HAPD)

用液相外延和锌扩散技术成功地制造了具有 In_(0·53)Ga_(0·47)As 光吸收层和 InP 雪崩倍增层的异质结构雪崩光电二极管(HAPD)。这种 HAPD的雪崩增益已经高达1.6×10~4,暗电流密度在0.9V_B 下低至1×10~(-5)A/cm~2。     

High-speed photodiode signal enhancement at avalanche breakdown voltage

It has previously been found that when photons are injected into a photodiode biased to the avalanche region, that there is a multiplication of the signal over the usual bias-voltage signal level. This multiplication is due to the created electron-hole pairs colliding with the lattice and creating more electron-hole pairs under the influence of the large biasing field. This paper presents a circuit analysis of this effect when using a high-speed silicon (Si) P-I-N photodiode and shows what the SNR bandwidth and Noise Equivalent Power (NEP) are under both normal bias conditions and avalanche bias conditions. It is shown that there is a substantial improvement in the NEP and SNR ratio at high frequencies when operating at avalanche so that the device may be made nearly shot noise limited if the multiplication factorMis sufficiently large. Microwave measurements on such a high-speed diode gave gains greater than 30 dB with a SNR improvement of 13 dB at 1.45 Gc/s. The effect was observed at frequencies as high as 2.54 Gc/s and appeared to follow a linear 1/M law with bias voltage in the avalanche region with some deviation at large values ofM. The device SNR ratio at moderately high light levels is determined by the signal-to-shot noise ratio. A high modulation depth is found to be essential to reduce shot noise. Analysis of the diode circuit reveals that the detected signal power bandwidth product is a constant. The NEP is found to vary directly with the bandwidth in a pulse type system. Avalanche operation increases the signal power by M²and decreases the NEP byMat high frequencies. The photodiode appears to nearly provide the solid-state analog of the photomultiplier tube.     

Noise in solid-state devices and lasers

A survey is given of the most important noise problems in solid-state devices. Section II discusses shot noise in metal-semiconductor diodes, p-n junctions, and transistors at low injection; noise due to recombination and generation in the junction space-charge region; high-level injection effects; noise in photodiodes, avalanche diodes, and diode particle detectors, and shot noise in the leakage currents in field-effect transistors (FETs). Section III discusses thermal noise and induced gate noise in FETs; generation-recombination noise in FETs and transistors at low temperatures; noise due to recombination centers in the space-charge region(s) of FETs, and noise in space-charge-limited solid-state diodes. Section IV attempts to give a unified account of 1/f noise in solid-state devices in terms of the fluctuating occupancy of traps in the surface oxide; discusses the kinetics of these traps; applies this to flicker noise in junction diodes, transistors, and FETs, and briefly discusses flicker noise in Gunn diodes and burst noise in junction diodes and transistors. Section V discusses shot noise in the light emission of luminescent diodes and lasers, and noise in optical heterodyning. Section VI discusses circuit applications. It deals with the noise figure of negative conductance amplifiers (tunnel diodes and parametric amplifiers), and of FET, transistor, and mixer circuits. In the latter discussion capacitive up-converters, and diode, FET, and transistor mixers are dealt with.     

Experimental Evaluation of Noise Parameters in Gunn and Avalanche Oscillators

Equations are presented that express noise-to-carrier ratio and rms frequency deviation of a negative-resistance oscillator with a multiple-resonant circuit in terms of effective available noise power densities of both 1/f and white-noise sources, an effective saturation factor, and an appropriate Q/sub L/ of the oscillator. Experimental evaluation of the noise parameters in Gunn and avalanche oscillators by use of these equations is described. AM and FM noise measurements have been made on X-band Gunn oscillators and Si and GaAs avalanche oscillators for frequency off carriers extending from 1 kHz to 10 MHz. Both 1/f and white noise have been observed in these oscillators. The validity of the above equations has been verified for Gunn oscillators from the dependence of the noise spectra on Q/sub L/. For Gunn oscillators and Si and GaAs avalanche oscillators, the effective noise-temperature ratio for white noise, N/kT/sub 0/, has been found to be 23~29, 41~51, and 38~44 dB, and the effective saturation factor to be 2~2.9, 0.5~2.4, and 2, respectively. An increase of N/kT/sub 0/ with the RF voltage across the diode has been observed in Si avalanche oscillators. Parameters for 1/f noise have also been evaluated approximately.     

半导体抽运Nd:YAG激光器强度噪声抑制的研究

为了降低半导体抽运固体激光器的弛豫振荡噪声,提高其输出功率的稳定性,采用光电负反馈的方法来抑制半导体抽运的固体激光器的强度噪声,并对激光器强度噪声的理论特性进行了分析。根据理论分析结果设计了比例-积分-微分反馈控制电路,通过运用该反馈电路对激光器进行强度噪声抑制实验,得到了比较理想的实验数据,即当抽运功率为700mW、弛豫振荡峰频率为300kHz时,弛豫振荡峰值处和低频区域强度噪声分别降低了45dB和15dB;当抽运功率为550mW、弛豫振荡峰值为250kHz时,弛豫振荡峰值处和低频区域强度噪声分别降低了40dB和10dB。结果表明,该反馈控制电路能够有效地降低半导体抽运固体激光器的强度噪声,提高激光器输出功率的稳定性。     

Noise theory for the read type avalanche diode

An analysis is presented for the noise current spectrum of an avalanche diode under assumed conditions of ideal uniform avalanche behavior in a zone which is thin compared with the total high-field depletion zone. The result is applied to the Read diode amplifier. For a typical set of operating parameters, the theory predicts a noise figure on the order of 40 dB. Depending upon particular device parameters, lower noise figures may be possible.     

An Improved Solid-State Noise Source (Short Papers)

An improved solid-state noise source is discussed. By implementing such modifications as 1) heat sinking of a silicon avalanche noise diode, 2) proper dc RF decoupling, and 3) impedance matching, the stability of the National Bureau of Standards (NBS) solid-state noise source is improved significantly over that of typical commercial solid-state noise sources. These modifications, how they are implemented, and the resulting improvement in stability are described.     

Effect of tunneling current on the noise characteristics of a 4H-SiC Read Avalanche diode

Noise characteristics of a Read Avalanche diode are analyzed by incorporating the tunneling mechanism of the electron into the avalanche mechanism.Analytical expressions are presented for the mean square noise voltage and noise measure in MITATT(mixed tunneling and avalanche transit time) mode operation.A wide band gap semiconductor(4H-SiC) based MITATT diode is considered to study the effect of tunneling on the noise characteristics and negative conductance.While exhibiting enough potential for 4H-SiC to be used as a terahertz source of power in the MITATT mode,our results record a noise measure of 35.18 dB at a frequency of 1.5 THz.     

宽带单片低噪声放大器

由电路和噪声基本定义出发,导出了二端口网络的噪声相关矩阵的转移表示式和导纳表示式.并推导了两个二端口网络的级联和并联后的噪声相关矩阵.然后在此基础上得出了并联反馈放大器的噪声参数(R_n,NF_min和Y_opt)和其S参数表达式.由此设计和制造了1~7GHz两级单片低噪声放大器.在工作频率1~7GHz内,测得增益G＞20dB,带内增益波动ΔG≤±0.75dB,噪声系数NF≤2.5dB,输入输出驻波VSWR≤2.0,1分贝压缩点输出功率P_1dB≥15dBm.测试结果验证了设计的正确性.     

一种单光子探测器前置超宽带低噪声放大器的设计

为了进一步提高单光子探测器的性能,设计并研制了利用高电子迁移率晶体管基于混合集成负反馈结构的低成本、超宽带、低噪声前置放大器,并利用ADS软件对该放大器进行了优化和仿真。该放大器工作频段5MHz～6GHz,功率增益19.5±0.61dB,噪声系数小于2.6dB,输入电压驻波比和输出电压驻波比均小于1.8,仿真和实验结果表明该放大器可以将雪崩光电二极管上产生的亚纳秒级雪崩信号幅度放大10倍,满足单光子探测器日益提高的探测频率需求。     

宽带高增益输出平衡CMOS低噪声放大器的设计

设计了一种带片内变压器、适用于0.05～2.5 GHz频段的宽带低噪声放大器(LNA).电路设计采用了并行的共栅共源放大结构,将从天线接收到的单端输入信号转换为一对差分信号输出给后级链路.针对变压器结构的LNA噪声系数不够低和输出不平衡的问题,采用了缩放技术、噪声消除技术以及两级的全差分放大器作为输出缓冲级,来有效降低电路的噪声系数,提高增益和输出平衡度.电路采用TSMC 0.18μm 1P6M RF CMOS工艺设计仿真和流片,测试结果表明:在0.05 ～ 2.5 GHz频带范围内,该LNA的最高功率增益达24.5 dB,全频段内噪声系数为2.6～4 dB,输入反射系数小于-10 dB,输出差分信号幅度和相位差分别低于0.6dB和1.8°.