Δ-∑A／D转换器中数字下变频解调器的设计与实现

从集成电路设计技术的角度，介绍了Δ-∑A／D转换器中数字下变频解调器的原理和集成实现方法。釆用CSD码，用CIC滤波器、半带滤波器，实现了16位Δ-∑A／D转换器中的抽取器。对所设计的HDL代码进行了综合及仿真。结果表明，设计达到了精度要求，且具有速度快、面积小的特点。     

一种16位音频∑△ A/D转换器

提出了一种16位立体声音频新型稳定的5阶∑△A/D转换器.该转换器由开关电容∑△调制器、抽取滤波器和带隙基准电路构成.提出了一种新的稳定高阶调制器的方法和一种新的梳状滤波器.采用0.5μm 5V CMOS工艺实现∑△A/D转换器.∑△A/D转换器可以得到96dB的峰值SNR,动态范围为96dB.整个芯片面积只有4.1mm×2.4mm,功耗为90mW.     

Σ-Δ模数转换器工作原理及简单分析

∑-ΔA/D转换器是一种高精度的模数转换器,它和传统的A/D转换器不同,具有高分辨率、高集成度、造价低和使用方便的特点,并且越来越广泛地使用在一些高精度仪器仪表和测量设备中。文章从信号的过采样、噪声整形、数字抽取滤波等方面分析了∑-ΔA/D转换器的工作原理,对人们全面了解∑-ΔA/D转换器有一定的帮助。     

一种稳定的高阶∑—△模／数转换器

文章提出了一种稳定的高阶∑-△模数转换器的设计方法。结合实例，简要说明了多级数字抽取滤波器的设计，并讨论了调制器基内零点优化的方法。设计的∑-△A/D转换器可以满足无线通信应用中大动态范围A/D转换的要求。     

一种Σ-Δ A/D转换器抽取滤波器的设计

设计了一种Σ-ΔA/D转换器中的数字抽取滤波器。该滤波器应用于音频范围,采用多级多采样率的结构,由梳状滤波器、补偿滤波器以及两个半带滤波器组成。滤波器系数用标准符号编码实现,减少了乘法单元的使用。采用Simulink模拟过采样128倍的4位调制器输出;用Verilog编写用于测试的滤波器代码。在Matlab中分析滤波器输出码流,得到的信噪比为101 dB,能够满足高端音频A/D转换器的要求。     

A 16 bit Stereo Audio ΣΔ A/D Converter

提出了一种16位立体声音频新型稳定的5阶∑△A/D转换器.该转换器由开关电容∑△调制器、抽取滤波器和带隙基准电路构成.提出了一种新的稳定高阶调制器的方法和一种新的梳状滤波器.采用0.5μm 5V CMOS工艺实现∑△A/D转换器.∑△A/D转换器可以得到96dB的峰值SNR,动态范围为96dB.整个芯片面积只有4.1mm×2.4mm,功耗为90mW.     

一种稳定的高阶Σ-Δ模/数转换器

文章提出了一种稳定的高阶Σ-Δ模数转换器的设计方法.结合实例,简要说明了多级数字抽取滤波器的设计, 并讨论了调制器基带内零点优化的方法.设计的Σ-Δ A/D转换器可以满足无线通信应用中大动态范围A/D转换的要求.     

△-∑A/D转换器中数字下变频解调器的设计与实现

从集成电路设计技术的角度,介绍了△-∑A／D转换器中数字下变频解调器的原理和集 成实现方法。采用CSD码,用CIC滤波器、半带滤波器,实现了16位△-∑A／D转换器中的抽取器。 对所设计的HDL代码进行了综合及仿真。结果表明,设计达到了精度要求,且具有速度快、面积小 的特点。     

一种单环5阶高精度音频△-∑ A/D转换器

采用英飞凌0.11 μm CMOS工艺,实现了一种用于音频范围的高精度△-∑ A/D转换器.调制器采用1位量化的5阶单环前馈结构,ADC过采样率为256.A/D转换器模拟调制器工作于5V电压,数字滤波器工作于1.2V电压,整体功耗为20.52 mW,版图面积3.1 mm2.仿真结果显示,设计的A/D转换器在20 kHz信号带宽内达到108.9 dB的信噪失真比,有效位数为18位.     

一种用于过采样Σ-Δ A/D转换器的抽取滤波器

采用0.8 μm CMOS工艺,实现了一种用于过采样Σ-Δ A/D转换器的数字抽取滤波器.该滤波器采用多级结构,梳状滤波器作为首级,用最佳一致逼近算法设计的FIR滤波器作为末级,并通过位串行算法硬件实现.芯片测试表明,该滤波器对128倍过采样率、2阶Σ-Δ调制器的输出码流进行处理得到的信噪比为75 dB.     

DDC中的抽取滤波器设计及FPGA实现

本文介绍了在数字下变频（DDC）中的抽取滤波器系统设计方法和具体实现方案。采用CIC滤波器、HB滤波器、FIR滤波器三级级联的方式来降低采样率。通过实际验证，证明了设计的可行性。     

Inverse Ultraspherical Filters

The inverse ultraspherical filter is derived and its properties analyzed. It is shown that the inverse ultraspherical filter has smaller transition band than the inverse Chebyshev filter under certain circumstances while still maintaining the maximally flat passband characteristic. Filter pole and zero calculations are described and typical magnitude and delay responses generated. Nomographs of inverse ultraspherical filters are also provided for determining filter order and for possible magnitude response optimization.Celestino A. Corral was born in Havana, Cuba. He earned his Bachelors, Masters and Ph.D. degrees in electrical engineering from the University of Miami, Florida, in 1985, 1987, and 1993, respectively. He completed his Ph.D. program under a Patricia Roberts Harris fellowship. From 1988 to 1990 Dr. Corral was a Member of the Technical Staff at Sandia National Laboratories, Albuquerque, New Mexico, where he was involved in the analysis, modeling, and design of custom circuits for piezoelectric sensor components. In 1994, he joined Scientific-Atlanta in Atlanta, Georgia, as an Associate Staff RF Engineer and worked on communication systems and specialized microwave software. In 1997 he was Senior Design Engineer at Origin Data Systems in Boca Raton, Florida, where he had multiple roles in system, hardware, and software development for a novel asset management/RFID system. Currently, Dr. Corral is a Distinguished Member of the Technical Staff in Motorola Labs, Plantation, Florida, and is involved in ultra-wideband, wideband, and propagation research. His interests include circuit and filter theory, communication systems, numerical analysis, signal processing, and constrained optimization. He has published over twenty-five journal and conference papers, has six patents filed, and two trade secrets.Dr. Corral was principal recipient of the Myril B. Reed Best Paper Award for the 40th Midwest Symposium on Circuits and Systems in 1997. Dr. Corral is also the principal recipient of the Ambrose Fleming Premium for IEE Proceedings on Circuits, Devices, and Systems, 2000. Dr. Corral is a Senior Member of IEEE and a member of Omicron Delta Kappa, Tau Beta Pi, and Eta Kappa Nu honor societies.     

波导带通滤波器的精确设计和快速优化

介绍了采用三维微波电磁场仿真软件快速提取直接耦合波导带通滤波器耦合窗口参数的方法,并提出了优化最终模型的快速扫描技术.全波仿真及实验结果表明,该方法能满足波导带通滤波器快速精确设计的要求.     

Design of two-dimensional directional filters

A directional filter has a passband extending fully along a straight line passing through the origin. In its original form the transformation technique, a powerful tool for designing two-dimensional FIR filters, is not useful to design such a filter. In this communication we suggest a few analytical and optimisation-based methods to design directional filters using the transformation technique. The superiority of the proposed methods over existing techniques is demonstrated.     

一种基于CIC滤波器的有效锐化方法研究

介绍了对积分梳状滤波器（CIC滤波器）的有效锐化。所提出的锐化滤波器的结构由两个主要部分组成：一个梳状滤波器的级联部分和一个锐化滤波器部分。所提出的方案使得滤波器中锐化部分的工作速率比输入速率大为降低，其频谱响应特性比传统的也有所改进。通过MATLAB仿真，可看出改进锐化后的滤波器性能更优。     

Current-mode continuous-time filters using complementary current mirror pairs

A design of current-mode continuous-time filters for low voltage and high frequency applications using complementary bipolar current mirror pairs is presented. The proposed current-mode filters consist of simple bipolar current mirrors and capacitors and are quite suitable for monolithic integration. Since the filters are based on the integrator type of realization, the proposed method can be used for a wide range of applications. The frequency of the filters can easily be changed by the DC controlling current. A fifth-order Butterworth and a third-order leapfrog filter with tunable cutoff frequencies from 20 MHz to 100 MHz are designed as examples and simulated by SPICE using standard bipolar parameters.     

大功率谐波吸收式滤波器设计

介绍了大功率谐波吸收式滤波器的实现电路，这些电路满足了信号分流的技术要求。文中给出了详细的工作原理和测试数据。     

Miniaturized dielectric waveguide filters

Design techniques for a new class of integrated monolithic high-permittivity ceramic waveguide filters are presented. These filters enable a size reduction of 50% compared to air-filled transverse electromagnetic filters with the same unloaded Q-factor. Designs for Chebyshev and asymmetric generalised Chebyshev filter and a diplexer are presented with experimental results for an 1800 MHz Chebyshev filter and a 1700 MHz generalised Chebyshev filter showing excellent agreement with theory.     

二维自适应排序滤波器及其实时实现的几点考虑

本文首先提出了二维自适应排序滤波器２ＤＡＲＯＦ（ＴｗｏＤｉｍｅｎｓｉｏｎａｌＡｄａｐｔｉｖｅＲａｎｋＯｒ－ｄｅｒＦｉｌｔｅｒ）的结构和算法，然后分析了收敛系数和不同扫描方式在图像处理应用中对收敛和滤波性能的影响。考虑到实时处理的需要，本文还讨论了在实时实现时的几点考虑。最后，给出了２ＤＡＲＯＦ在图像去噪和恢复中的应用实例。     

A CMOS Monolithic Image-Reject Filter

A CMOS inductorless image-reject filter based on active RLC circuitry is discussed and designed with the emphasis on low-noise, low-power, and gigahertz-range circuits. Two -enhancement techniques are utilized to circumvent the low characteristics inherent in the simple feedback circuit. The frequency tuning is almost independent of tuning, facilitating the design of the automatic tuning circuitry. The stability and the tuning scheme of the filter are also discussed. Simulations using 0.6 m CMOS technology demonstrate the feasibility of the tunable image-reject filter for GSM wireless applications. Simulation results show 4.75 dB voltage gain, 9.5 dB noise figure, and –20 dBm IIP3 at a passband centered at 947 MHz. The image signal suppression is 60 dB at 1089 MHz and the power consumption is 27 mW.