Ku波段固态倍频源

采用晶振－倍频链的方式研制生产了１３ＧＨＺ的微波固态频率源。在－５５￣＋８５℃温度内,输出功率优于２５０ｍＷ相位噪声为－１０２ｄＢ／１ｋ、－１１０ｄＢ。１０ｋ     

AD604超低噪声双通道可变增益放大器

特点在最大增益情况下具有超低输入噪声０．８０ｎＶ／　Ｈｚ,３．０ｐＡ／　Ｈｚ两个独立通道ｄＢ成线性可变增益放大器每个通道可编程绝对增益范围从０ｄＢ～＋４８ｄＢ（前放增益＝＋１４ｄＢ）到＋６ｄＢ～＋５４ｄＢ（前放增益＝＋２０ｄＢ）增益精度：±１．０ｄＢ－３ｄＢ带宽：４０ＭＨｚ输入电阻：３００ｋ可变增益系数：２０ｄＢ／Ｖ～４０ｄＢ／Ｖ增益对温度和电源变化保持稳定单端单极性增益控制在增益控制低端,电源待机可直接驱动Ａ／Ｄ转换器应用超声和声纳时间增益控制高性能自动增益控制（ＡＧＣ）系统信号测量ＡＤ９８０…     

PBSZT弛豫铁电陶瓷偏压压电效应的研究

研究了镧和铋掺杂的锆钛酸铅钡锶（ＰＢＳＺＴ）弛豫铁电陶瓷在不同直流偏压及温度下的介电常数ε３３、平面机电耦合系数ｋｐ 和等效横向压电常数ｄ３１。实验表明,ＰＢＳＺＴ弛豫铁电陶瓷的ｄ３１值可由直流偏压控制且温度系数远小于ＰＭＮ－ＰＴ系陶瓷。室温下镧和铋掺杂的ＰＢＳＺＴ陶瓷在１０ ｋＶ／ｃｍ 的偏压下｜ｄ３１｜分别为２１０ ｐＣ／Ｎ和２２０ ｐＣ／Ｎ。     

β—BBO晶体压电应变系数的测量

用干涉法和准静态ｄ３３测量仪相结合测量了β－ＢａＢ２Ｏ４（β－ＢＢＯ）晶体的全部电压变变系数，结果为：ｄ３３＝１．０×１０＾－１２Ｃ／Ｎ，ｄ３１＝－０．８３×１０＾－１２Ｃ／Ｎ，ｄ２２＝２．２×１０＾－１２Ｃ／Ｎ，ｄ１５＝２１．２×１０＾－１２Ｃ／Ｎ。     

锁相介质振荡器

锁相介质振荡器采用锁柏稳频技术将介质振荡器的频率稳定在参考频率上。研制的一种Ｘ波段锁相介质振荡器,得到的性能指标如下：频率８．４４８ＧＨｚ;相位噪声≤ －８０ｄＢＣ／Ｈｚ＠１００ｋＨｚ、≤－１１０ｄＢ／Ｈｚ＠１００ｋＨｚ;输出功率≥１０ｄＢｍ;杂波≤－７５ｄＢｃ、谐波≤－３０ｄＢｃ。     

β－BBO晶体压电应变系数的测量

用干涉法和准静态ｄ_（３３）测量仪相结合测量了β－ＢａＢ_２Ｏ_４（β－ＢＢＯ）晶体的全部压电应变系数，结果为：ｄ_（３３）＝１．０×１０~（１２）Ｃ／Ｎ，ｄ_（３１）＝－０．８３×１０~（１２）Ｃ／Ｎ，ｄ_（２２）＝２．２×１０~（１２）Ｃ／Ｎ，ｄ_（１５）＝２１．２×１０~（１２）Ｃ／Ｎ。     

S波段频率综合技术研究

本文论述的Ｓ波段频率综合器，频率范围是２．６１￣３．９６ＧＨｚ，频率步进为２．５ＭＨｚ，相位噪声指标〈－（８８￣９３）ｄＢｃ／Ｈｚ，长期频率稳定度为１×１０＾－９／日，杂散抑制优于５５ｄＢ，谐波抑制优于５０ｄＢ，输出功率大于１４ｄＢｍ。     

2.5～4.4Gb／s光纤无中继传输实验系统

本文报导在４×６２２Ｍｂ／ｓ）×１６０ｋｍ等三个常规单模光纤无中继传输实验系统，以及４．３５４Ｇｂ／ｓ×２００ｋｍ常规单模光纤传输实验系统方面的研究成果．带有掺饵光纤功放的高稳定度光发射机输出功率分别＞＋４ｄＢｍ／信道（４×６２２Ｍｂ／ｓ）和１１ｄＢｍ（单路２．５Ｇｂ／ｓ），频率稳定度分别优于６×１０－６和４．１×１０－６．带有掺铒光纤前放的四路光接收机灵敏度达到－４６．８ｄＢｍ（６２２Ｍｂ／ｓ，ＮＲＺ２２３－１ＰＲＢＳ）和－３９．５ｄＢｍ（４×２．５Ｇｂ／ｓ，ＮＲＺ２２３－１ＰＲＢＳ）．系统各信道误码率分别优于４×１０－１２～４×１０－１５．     

声表面波大带宽滤波器的设计

报道在Ｙ旋１２７．８６°Ｘ传ＬｉＮｂＯ＿３基片上采用１／８λ＿０，５／８λ＿０结构的切指加权换能器的声表面波滤波器，成功地研制了中心频率为４０ＭＨｚ，３ｄＢ带宽为２０ＭＨｚ，矩形系数（Δｆ＿４０ｄＢ／Δｆ＿３ｄＢ）为１．４８，带内波动＜１．２ｄＢ，带外抑制＞４０ｄＢ．插入损耗＜３８ｄＢ，相对带宽（Δｆ＿－３ｄＢ／ｆ＿０）大于５０％的滤波器。     

L波段数字锁相环频率合成器的研究

本文介绍了一种Ｌ波段锁相环频率合成器，频率范围１．１－１．６ＧＨＺ，频率步进为１ＭＨＺ，相位噪声为ε（１０ｋＨｚ）〈－９０ｄＢｃ／Ｈｚ杂散抑制优于５５ｄＢ，输出功率≥０ｄＢｍ。     

Novel transition between different configurations of planartransmission lines

New designs of coplanar waveguide (CPW)-microstrip, CPW-stripline, conductor backed CPW (CBCPW)-microstrip, and CBCPW-stripline transitions are presented. Simulation using the high frequency structures simulator (HFSS) shows that the return loss of the CPW-microstrip transition is less than -25 dB up to 11 GHz. Similarly is the CPW-stripline transition. In the case of two back to back CBCPW-stripline transitions, the return loss is less than -22 dB up to 9 GHz. Experimentally, the S ₁₁ of two back to back CBCPW-microstrip transitions on an alumina substrate is less than -15 dB up to 25 GHz     

High frequency saturated CMOS floating resistor for fully-differential analogue signal processors

A floating resistor on a current source technique is introduced. All the transistors are saturated leading to higher frequency response than previously proposed techniques. Simulated results, using HSPICE level 3, for a 214 k Omega floating resistor have shown a -3 dB frequency of the order of 1 GHz. Its total harmonic distortion at 10.7 MHz and including 2% worst case transistor mismatches is less than -62 dB for fully differential applied signals up to 2 V peak to peak.<>     

A wideband 2.4-GHz delta-sigma fractional-NPLL with 1-Mb/s in-loop modulation

A phase noise cancellation technique and a charge pump linearization technique, both of which are insensitive to component errors, are presented and demonstrated as enabling components in a wideband CMOS delta-sigma fractional-N phase-locked loop (PLL). The PLL has a loop bandwidth of 460 kHz and is capable of 1-Mb/s in- loop FSK modulation at center frequencies of 2402 + k MHz for k = 0, 1, 2, ..., 78. For each frequency, measured results indicate that the peak spot phase noise reduction achieved by the phase noise cancellation technique is 16 dB or better, and the minimum suppression of fractional spurious tones achieved by the charge pump linearization technique is 8 dB or better. With both techniques enabled, the PLL achieves a worst-case phase noise of -121 dBc/Hz at 3-MHz offsets, and a worst-case in-band noise floor of -96 dBc/Hz. The PLL circuitry consumes 34.4 mA from 1.8-2.2-V supplies. The IC is realized in a 0.18-/spl mu/m mixed-signal CMOS process, and has a die size of 2.72 mm /spl times/ 2.47 mm.     

Implementation of perfect-magnetic-coupling ultralow-loss transformer in RFCMOS technology

In this letter, we propose a single-turn multiple-layer interlaced stacked transformer structure with nearly perfect magnetic-coupling factor (k/sub IM//spl sim/1) using standard mixed-signal/RF CMOS (or BiCMOS) technology. A single-turn six-layer interlaced stacked transformer was implemented to demonstrate the proposed structure. Temperature dependence (from -25/spl deg/C to 175/spl deg/C) of the quality-factor (Q-factor), k/sub Im/, resistive-coupling factor (k/sub Re/), maximum available power gain (G/sub Amax/), and minimum noise figure (NF/sub min/) performances of the transformer are reported. State-of-the-art G/sub Amax/ of 0.762 and 0.904 (i.e., NF/sub min/ of 1.181 dB and 0.437 dB) have been achieved at 5.2 and 8 GHz, respectively, at room temperature, mainly due to the perfect magnetic-coupling factor and the high resistive-coupling factor. The present analysis is helpful for RF engineers to design ultralow-voltage high-performance transformer-feedback low-noise amplifiers and voltage-controlled oscillators, and other radio frequency integrated circuits which include transformers.     

Multiple-wavelength conversion with gain by a high-repetition-rate pulsed-pump fiber OPA

The authors propose and demonstrate a novel multiple-wavelength converter with gain, based on a pulsed-pump fiber optical parametric amplifier (OPA). It generates multiple replicas of the signal, as well as spectrally inverted versions. The device is modeled by using quasi-steady-state OPA gain equations, as well as by the split-step Fourier method. Predicted conversion gains of up to 20 dB have been confirmed by experiments. A 10-Gb/s nonreturn-to-zero (NRZ) input signal was converted into several replicas, with penalties ranging from 0.26 to 1.24 dB for frequency shifts of /spl plusmn/k/spl times/100 GHz (k=1, 2, 3, 4).     

阻焊对高速PCB插损性能的影响

基于频域法利用矢量网络分析仪对3种不同基材但层叠结构完全一致的高速PCB上85Ω差分微带线在覆盖阻焊油墨前后插损的变化情况进行了研究。结果表明,以4 GHz条件下S7083基材为例,覆盖不同阻焊油墨后,微带线插损增量绝对值在0.03 dB/in至0.09 dB/in之间变化;印刷1次及2次LP-4G-G11阻焊油墨后,微带线插损绝对值增量由0.05 dB/in增加至0.07 dB/in;由较低D k与D f材料所制备的PCB,在覆盖相同的阻焊油墨之后,微带线插入损耗值增量绝对值较大。     

Quantitative analysis of 2-f.s.k. traffic detection

Two different methods of detecting signal flow in a noncoherent 2-f.s.k. channel are analysed with respect to the necessary signal/noise ratio for a certain error probability. It is found that separate detection of each frequency requires s.n.r. ?18 dB compared to about 19.5 dB for sum detection when the error probability is 10?7.     

GMSK信号的多普勒频移快捕和跟踪

GMSK信号具有良好的频谱和功率特性,特别适用于功率受限和信道存在非线性、衰落以及多普勒频移的数字卫星移动突发通信系统。本文提出了一种GMSK信号的多普勒频移快捕和跟踪方法。该方法根据突发通信时帧结构的特点,采用独特码和FFT并行处理信号能量检测、帧同步检测和多普勒频移快捕,并采用判决反馈PLL环跟踪多普勒频移的变化。仿真结果表明,多普勒频移在-Rb／2～Rb/2范围内变化时,与理论值相比,采用该方法的准相干解调器误比特率Pb 性能恶化仅为0．3dB。在信息速率Rb=9．6kbps时,多普勒频移速率可达4000Hz／s。     

Distribution and Frequency Dependence of Unintentionally Generated Man-Made VHF/UHF Noise in Metropolitan Areas. Part II-Theory

The frequency and range dependence of unintentionally generated man-made VHF/UHF noise in metropolitan areas may be interpreted by assuming that it is composed of random impulses which have been attenuated by propagation over irregular terrain. Man-made noise power per cycle of bandwidth measured for the frequency interval 150 to 500 Mc/s is shown to possess decrements of -10.4 dB/decade change in frequency and -17.9 dB/decade change in range. Theoretical computations of the frequency and range decrements based on a random impulse, irregular terrain model yield frequency and range decrements of -11.1 to -11.3 dB/frequency decade and -17.3 to -18.3 dB/range decade which are in good agreement with the measured results. Comparison of the measured VHF/UHF decrements for unintentionally generated man-made noise in urban and suburban areas with those derived from data which were predominantly of automotive ignition origin supports the conclusion that automotive ignition interference is the major source of man-made noise at these frequencies.     

Two-stage broadband high-gain W-band amplifier using 0.1-/spl mu/m metamorphic HEMT technology

We report broadband high-gain W-band monolithic microwave integrated circuit amplifiers based on 0.1-/spl mu/m InGaAs-InAlAs-GaAs metamorphic high electron mobility transistor (MHEMT) technology. The amplifiers show excellent S/sub 21/ gains greater than 10 dB in a very broad W-band frequency range of 75-100 GHz, thereby exhibiting a S/sub 21/ gain of 10.1 dB, a S/sub 11/ of -5.1 dB and a S/sub 22/ of -5.2 dB at 100 GHz, respectively. The high gain of the amplifier is mainly attributed to the performance of the MHEMTs exhibiting a maximum transconductance of 691 mS/mm, a current gain cutoff frequency of 189 GHz, and a maximum oscillation frequency of 334 GHz.