共查询到20条相似文献,搜索用时 687 毫秒
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通过理论仿真,该文研制了一种改进型的3IDT-LCR结构,并基于该结构在42°Y-X LiTaO3压电基片上研制出一种低损耗、小矩形系数的SAW滤波器。滤波器标称频率为253.75 MHz,实测插入损耗1.05 dB,低端带外抑制接近80 dB,高端带外抑制接近65 dB,-1 dB带宽10.52 MHz,-3 dB带宽12.54 MHz,-40 dB带宽16.68 MHz,矩形系数1.33。实测结果表明,该改进型3IDT-LCR结构的SAW滤波器具备低插入损耗、小矩形系数和高带外抑制的特点。 相似文献
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用于频率合成的声表面波滤波器 总被引:1,自引:1,他引:0
介绍了几组用于扩频系统的声表面波滤波器的设计、制作和实验结果.器件频率为95~350MHz.插入损耗为9~24dB.阻带抑制优于45dB. 相似文献
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松下电子工业有限公司研制出一种用于800-900MHz波段移动通信的低损耗声表面波(SAW)滤波器,其体积仅4.5×4.5×1.6mm。这种可用表面安装技术(SMT)的器件只有4dB的插入损耗,却有17-30MHz的带通。这种SAW滤波器的衬底为钽酸锂,其电极是以效率最佳的极精确的等效电路模型为基础。这种性能极佳的超小型器件采用陶瓷封装。本文将描述其主要的性能和特点。 相似文献
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A 5.2-GHz 11-dB gain, IP/sub 1 dB/=-17 dBm and IIP/sub 3/=-10 dBm double-quadrature Gilbert downconversion mixer with polyphase filters is demonstrated by using GaInP/GaAs heterojunction bipolar transistor (HBT) technology. The image rejection ratio is better than 40 dB when LO=5.17 GHz and intermediate frequency (IF) is in the range of 15 MHz to 40 MHz. The Gilbert downconverter has four-stage RC-CR IF polyphase filters for image rejection. Polyphase filters are also used to generate local (LO) and radio frequency (RF) quadrature signals around 5 GHz in the double-quadrature downconverter because GaAs has accurate thin film resistors and the low parasitic semi-insulating substrate. 相似文献
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针对宽带雷达线性调频信号产生,采用FPGA电路和宽带DAC电路直接产生50 MHz~550 MHz 的线性调频中频信号。将中频信号上变频到2 GHz~2. 5 GHz 的射频频段,再经过2 倍频获得4 GHz~5 GHz的宽频带线性调频信号。为进一步提高射频输出信号的幅度/相位特性,采用幅/相预失真校准方法,并精心设计信号产生系统的中频电路和射频电路,进行了实验研究与分析。对实际系统的测试结果表明,系统产生LFM信号的带外杂散优于-55 dB,带内起伏小于依2 dB,且系统稳定、可靠。 相似文献
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一些声表面波器件的市场应用及发展 总被引:3,自引:0,他引:3
简明阐述了声表面波(SAW)器件的一些应用和新发展,并例举了表贴SAW射频、中频滤波器在北美CDMA/PCS双模制式终端内的典型应用,分别对比了国内外供应商推向CDMA系统的SAW 69.99 MHz和114.99 MHz中频滤波器及终端Rx用881.5 MHz SAW射频表贴滤波器的性能指标,并提出了一些意见和看法。 相似文献
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回顾了低损耗声表面波滤波器的主要设计方法,介绍了镜像阻抗连接换能器结构中调整滤波器带宽的设计技术,给出了在960MHz高频下的两种试验结果,相对带宽分别为1%和2%,插入损耗小于5dB,阻带抑制优于50dB。 相似文献
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Weger P. Schultes G. Treitinger L. Bertagnolli E. Ehinger K. 《Electronics letters》1991,27(7):570-571
A monolithically integrated mixer based on a Gilbert cell multiplier for ultra-broadband applications has been produced in self-aligning 1 mu m silicon bipolar technology. Positive power conversion gain bandwidths for RF and LO up to 17.3 GHz and for the intermediate frequency (IF) up to 13 GHz were measured. The corresponding -3 dB frequencies are 9 GHz for RF and LO (IF=100 MHz) and 8 GHz (f/sub LO/=1 GHz) for IF.<> 相似文献
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Youngwook Kim Youngsik Kim Soonghak Lee 《Microwave and Wireless Components Letters, IEEE》2002,12(6):204-205
A predistortion technique has been proposed to reduce intermodulation distortion (IMD) generated from the conversion process of a mixer. In this technique, the IMD generated from a mixer in the IF band was cancelled by the controlled RF error signal, which is generated by a predistorter. The magnitude and phase of the RF error signal were properly adjusted through a vector modulator. This linearization technique has been verified by experiment of a down conversion mixer in the cellular band. A two tone test has been performed at the frequency of 836 MHz with 442 kHz separation. The results show that this method improves about 16 dB of IMD3 at -18 dBm IF output power in 10 MHz frequency band and increases about 3.5 dB of P1 dB of the mixer. Simple topology and good performance in linearization of IF signals renders this technique suitable for highly linear frequency conversion in communication systems 相似文献
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P. J. Sullivan B. A. Xavier W. H. Ku 《Analog Integrated Circuits and Signal Processing》1999,19(2):181-188
A CMOS doubly balanced mixer circuit is implemented with a source follower input and a cross coupled mixing quad. The circuit employs an all N-channel configuration and is suitable for high frequency applications. As a down-converter with an RF input of 2.0 GHz and an IF output of 200 MHz, the mixer demonstrates 9 dB of conversion loss with a corresponding input referred third order intercept of 0 dBm. As an up-converter with an IF input frequency of 400 MHz and an RF output of 2.4 GHz, the mixer demonstrates 14 dB of conversion loss. 相似文献
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