共查询到20条相似文献,搜索用时 31 毫秒
1.
XuXiaomei 《电子科学学刊(英文版)》2002,19(3):311-314
An anti-aliasing filter for ΣΔ ADCs using a combination of active RC and analog FIR filters is presented in this letter. The
first order active RC filter is set at 100kHz to minimize the die size and variations of linear phase and gain in 0–4kHz passband.
The 2-tap FIR filter provides more than −53dB attenuation at 2MHz ±4kHz frequency range. The proposed filter achieved more
than −76dB attenuation at sampling frequency with ±0.01° phase linearity and ±0.02dB gain variation within 0–4kHz bandwidth.
The active die area of the fully differential filter is 0.17mm2 in 0.5μm CMOS technology. The experimental and simulation results have been obtained and the feasibility of the proposed
method is shown.
Supported by Foundation for University Key Teacher by the Ministry of Education of China 相似文献
2.
We report periodical rocking long period gratings (PR-LPGs) in PANDA fibers fabricated with CO2 laser. The PR-LPGs achieve very high coupling efficiency of 19 dB with 12 periods and a 3.5° twist angle in just one scanning cycle, which is much more effective than the conventional CO2 laser fabrication technique. This type of LPGs exhibits polarization-selective resonance dips which demonstrate different sensitivities to environmental parameters. The high temperature and external refractive index sensitivities are measured simultaneously, so it can be used as a wavelength-selective polarization filter and sensor. This work has been supported by the National Natural Science Foundation of China (No.61605168), the Natural Science Foundation of Hebei Province (No.F2016203392), the College and University Natural Science Foundation of Hebei Province (No.QN2016078), the Science and Technology Project of Qinhuangdao City (No.201601B050), and the Intramural Doctoral Foundation of Yanshan Universtiy (No.B1011). E-mail:jinwa@ysu.edu.cn 相似文献
3.
Xu Xiaomei 《电子科学学刊(英文版)》2002,19(3)
An anti-aliasing filter for ∑△ ADCs using a combination of active RC and analog FIR filters is presented in this letter. The first order active RC filter is set at 100kHz to minimize the die size and variations of linear phase and gain in 0-4kHz passband. The 2-tap FIR filter provides more than -53dB attenuation at 2MHz ±4kHz frequency range. The proposed filter achieved more than -76dB attenuation at sampling frequency with ±0.01° phase linearity and ±0.02dB gain variation within 0-4kHz bandwidth. The active die area of the fully differential filter is 0.17mm2 in 0.5μm CMOS technology. The experimental and simulation results have been obtained and the feasibility of the proposed method is shown. 相似文献
4.
A tunable metamaterial filter is designed based on split-ring resonators (SRRs) in this paper. The metamaterial filter has a compact size of 15 mm×20 mm, and miniaturization is realized by using the SRRs. By loading tunable devices, the continuous operation of the filter is realized at X band (from 10.7 GHz to 12 GHz), the bandwidth is about 13%, the minimum return loss is 35 dB, and the maximum insertion loss is 0.37 dB. The results illustrate that the metamaterial filter shows the compact size, wide bandwidth and good band pass characteristics. This work has been supported by the Key Laboratory Foundation of China Electronics Technology Group Corporation (No.ZX15ZS391), the National Fund for International Cooperation in Science and Technology (No.2014DFR10020), and the Natural Science Foundation of Shanxi Province (Nos.2014021020-1 and 2015021083). E-mail:798710363@qq.com 相似文献
5.
6.
This paper proposes a new current-mode current-controlled single-input multiple-output type universal filter using non-inverting
and inverting second generation current-controlled conveyors (CCCII(±)s). The proposed circuit employs four CCCII(±)s and
two grounded capacitors, and it can simultaneously realize lowpass, bandpass, highpass, bandstop and allpass filter outputs.
The circuit offers an independent electronic control of the natural angular frequency (ω
0) and quality factor (Q) by means of adjusting the bias current of the CCCII(±)s. The parameter sensitivities are all very low. Moreover, a high
Q-value filter can be easily obtained by adjusting the ratio of two bias currents. PSPICE simulation results at the natural
frequency of 1.27 MHz are given to demonstrate the advantages of the proposed circuit.
This work was supported by National Natural Science Foundation of China under No.60676021. 相似文献
7.
A new multiple-taps and flat microwave photonic filter, which is composed of fiber Bragg grating, M-Z modulator and erbium-doped fiber, is put forward. The flat band-pass or flat band-stop response can be realized by adjusting the coupler's factor and the reflectivity of the fiber Bragg grating or the gain of the erbium-doped fiber. The free spectral range of the filter can be tuned by controlling the length of the erbium-doped fiber. The potential and feasibility of the proposed filtering structures have been demonstrated by simulation. 相似文献
8.
9.
10.
A wavelength multiplexer or demultiplexer plays ani mportant role in all wavelength division multiplexing( WDM) system.Silica-basedarrayed waveguide gratings(AWGs) offer attractive featuresinthis area due to theadvantage of large output channels and lowlo… 相似文献
11.
A fifth/seventh order dual-mode OTA-C complex filter for global navigation satellite system receivers is implemented in a 0.18 fxm CMOS process. This filter can be configured as the narrow mode of a 4.4 MHz bandwidth center at 4.1 MHz or the wide mode of a 22 MHz bandwidth center at 15.42 MHz. A fully differential OTA with source degeneration is used to provide sufficient linearity. Furthermore, a ring CCO based frequency tuning scheme is proposed to reduce frequency variation. The measured results show that in narrow-band mode the image rejection ratio (IMRR) is 35 dB, the filter dissipates 0.8 mA from the 1.8 V power supply, and the out-of-band rejection is 50 dB at 6 MHz offset. In wide-band mode, IMRR is 28 dB and the filter dissipates 3.2 mA. The frequency tuning error is less than ±2%. 相似文献
12.
LIYun-tao YUJin-zhong CHENShao-wu LIYan-ping CHENYuan-yuan 《光电子快报》2007,3(4):241-242
A rearrangeable nonblocking silicon-on-insulator-based thermo-optic 4x4 switch matrix with spot size converters (SSCs) and a new driving circuit are designed and fabricated. The introduction of a spot size converter (SSC) has decreased the insertion loss to less than 10dB and the new driving circuit has improved the response speed to less than l~s. 相似文献
13.
采用0.18μmCMOS工艺设计了一款应用在无线传网中的三阶级联有源RC复数带通滤波器,同时设计了自动频率调谐电路(AFT)。该滤波器采用的是切比雪夫逼近函数予以实现。在5比特数字控制码开关电容阵列的控制下,AFT电路即可完成对主体滤波器电路频率变化的校正。仿真结果显示,滤波器的中心频率稳定在2MHz,通带带宽为2MHz,镜像抑制比大于34dB,相邻信道阻带衰减大于34dB,通带纹波小于1dB,消耗电流为2.3mA,工作电源电压为1.8V。 相似文献
14.
15.
16.
JIA Da-gong JING Wen-cai ZHANG Yi-mo ZHOU Ge ZHANG Jin TANG Feng 《光电子快报》2005,1(3):221-223
A low-loss fiber optic rotary joint (FORJ) has been designed by using two kinds of C-lens collimators. Its insertion loss and insertion loss variation due to rotation with single-mode fiber collimator is less than 1.76 dB and 0.43 dB respectively. The maximum insertion loss and coupling variation due to rotation with multi-mode fiber collimator is 1.71 dB and 0.29 dB, respectively. This kind of FORJ features low insertion loss, small coupling variation due to rotation and low cost. 相似文献
17.
YANG Di WANG Yi-quan LV Mi CHEN Shao-wu YU Jin-zhong 《光电子快报》2007,3(5):334-336
A silicon-on-insulator 2× 2 Mach-Zehnder thermo-optical switch is developed based on strongly guided paired multimode interference couplers. The multimode-interference couplers were etched deeply for improving coupler characteristics such as self-imaging quality, uniformity and fabrication toierance. The proposed switch achieves good performances, including a low insertion loss of -11.0dB, a fiber-waveguide coupling loss of-4.3dB and a fast response speed measured to be 3.5 and 8.8 μs for raise and fall switching time, respectively. 相似文献
18.
CHI Hao ZHANG Xian-min SHEN Lin-fang 《光电子快报》2006,2(1):1-4
Photonic crystal fibers (PCFs) have attracted greatattentionin recent years due to their interesting proper-ties ,such as endless single-mode operation,unique dis-persion and nonlinear characteristics[1 ,2].It has been re-ported that PCFs offer a wide range of potential applica-tions ,such as 2Rregenerators ,optical parametric ampli-fiers ,dispersioncompensationandsuper-continuumgen-eration[3].Also called holey fibers or microstructure fi-bers ,PCFs are optical fibers possessing periodic a… 相似文献
19.
一种基于ADS的电调谐滤波器的新设计 总被引:1,自引:0,他引:1
设计了一种用于跳频通信系统接收机射频前端的UHF频段电调谐滤波器。使用安捷伦公司的
微波仿真软件ADS对电调谐滤波器进行结构设计和参数优化。对制成品的实际测试表明,该
调谐滤波器工作频段为225~400 MHz,3 dB带宽6.5~15 MHz,通带增益24~27 dB,矩形系
数小于6.2,其性能指标完全达到设计要求,在不同的频点都具有良好的电参数指标。所提
方法对电调滤波器的设计具有指导作用。 相似文献