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经过世博会筹备期的充分准备,世博会开幕式和开园仪式活动无线电频率保障工作取得了圆满成功。近日来,针对世博园开园后的频率使用特点.无线电保障工作部频率台站组在全面做好频率审批服务的同时,还进一步加大了频率复用力度,积极推进频率资源的有效利用,大大缓解了频率资源紧张的矛盾。 相似文献
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介绍了抗干扰通信、雷达系统中采用的频率捷变频技术,并对其关键技术——频率合成技术作了讨论,重点介绍了新型频率合成器——声表面波直接频率合成器。以一种100点声表面波直接频率合成器为例,该直接频率合成器具有小于3μs的频率切换时间(跳频速率达38000跳/s),-70dBc的虚假电平抑制,在500MHz偏离载频1kHz处相位噪声为-90dBc/Hz,100个频率点等多项优异性能。最后分析了声表面波直接频率合成器的应用前景和发展方向 相似文献
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《通信业与经济市场》2004,(2):21-21
2003年,我们在原有基础上进行了无线电频率规划,编写完成了无线电频率规划英文版工作,调整1800兆无线接入频率的容量,从原来5兆扩展到现在的20兆。对全国的台站进行了一次普查,而且对数据库进行了重新跟踪,对集群频率进行了 相似文献
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基于∑△调制的频率合成器及其性能 总被引:7,自引:0,他引:7
∑△模数变换器使用内部1位置化器就能提供较高分辨率的输出,将∑△调制技术应用于频率合成器中,能较好的提高频率合成器的频率覆盖范围,相位噪声及频率分辨率,定量地分析了∑△调制频率合成器的性能,给出了实现方法。 相似文献
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本文介绍了一种信号检测的方法——频率匹配,文中详细地叙述了频率匹配算法的原理,用Matlab从理论上证明了算法的正确性,在此基础上用可综合的RTL Verilog模型描述了算法,通过对综合后网表进行仿真,验证了频率匹配算法硬件实现的可行性。最后,根据频率匹配的原理,实现了一种高精度数字频率检测器,并给出了相关的精度值。 相似文献
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(yxl)φ切压电石英谐振器振动模式分析 总被引:1,自引:0,他引:1
从压电方程,动力学方程入手,分析了(yxl)φ切石英谐振器的厚度切变振动,利用自由边界条件及串联与并联谐振时的电学条件,求出了并联谐振频率和串联振频率,讨论了实测频率与频率公式存在一定偏差的原因。 相似文献
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介绍了频率合成的原理,常用几种频率合成技术及其优缺点。选择最常用的数字频率合成技术检验其合成频率的效果,在动态系统仿真软件SystemView环境下设计构建了一个数字频率合成器.并对其进行仿真分析,仿真结果表明,在滤波器带宽和VCO的载波最大变化范围内,可产生多个频率稳定的输出信号,达到设计要求。 相似文献
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本文介绍了把LTCC 技术和频率合成技术结合起来实现的Ka 波段频率合成器,采用带小数分频的双环结构同时实现了低相位噪声和高频率分辨率,并结合LTCC 技术,在表面安装有源器件,无源器件集成在基片内部,这样可以进一步提高系统集成度,实现小型化目标。该频率合成器输出频率为34.8GHz-35.2GHz,步进2MHz, 相位噪声为-5dBc/Hz@1kHz,-80dBc/Hz@10kHz,-90dBc/Hz@100kHz,通过合理布局,该频率合成器面积仅为42mm×49mm,与文献[2]相比面积缩小了37%。 相似文献
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Kurisu M. Uemura G. Ohuchi M. Ogawa C. Takemura H. Morikawa T. Tashiro T. 《Solid-State Circuits, IEEE Journal of》1992,27(12):1799-1804
A dynamic frequency divider applying the regenerative frequency division principle has been developed. A spiral inductor on the silicon substrate used as a load is characterized, and an improved one-port model with the substrate resistance is discussed. A 1/16 frequency divider was implemented with a silicon bipolar technology with a cutoff frequency of 40 GHz. The operation frequency range was 11.8-28.1 GHz, covering the Ka band (18-26.5 GHz). The inductive load has improved the maximum operation frequency by 7%, compared with a conventional circuit. Complemented with a 21-GHz static frequency divider previously reported by the authors, the whole microwave frequency range up to 26.5 GHz has been completely covered with the silicon bipolar technology. The maximum operation frequency of a silicon MMIC has been extended to the millimeter-wave frequency region for the first time 相似文献
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A new frequency notched ultra-wideband microstrip slot antenna with a parasitic tuning stub is proposed. The antenna is similar in configuration to a conventional microstrip slot antenna; by introducing a parasitic open-circuit tuning stub, flexible frequency notched function is achieved. Several properties of the antenna, such as frequency notched function, antenna transfer function and gain, have been investigated. As is reported, the operation bandwidth of the antenna is 2.91-11.16 GHz, in which a frequency notched band of 5.10-5.85 GHz has been achieved. Furthermore, good ultra-wideband linear transmission performance over the entire operation frequency range has also been achieved. 相似文献
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I. N. Kartashov M. V. Kuzelev 《Journal of Communications Technology and Electronics》2018,63(8):922-927
The beam instability in the plasma with density slowly varying with time has been investigated using the potential approximation. It has been shown that a frequency shift occurs in the amplified signal propagating in such an electrodynamic system; analytical relations for determining the value of this shift have been obtained. It is demonstrated that the frequency is shifted most strongly as the plasma density decreases, when the Langmuir frequency of plasma electrons approaches the signal frequency and the instability increment increases with time. 相似文献
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薄膜体声波谐振器(FBAR)电极层和压电层的厚度、材料是影响谐振频率的主要因素,确定各层的厚度和材料可得到期望的谐振频率。通过推导FBAR纵向运动应力方程,得到各层厚度、材料、频率参数与角频率相关的公式;采用MATLAB对FBAR各层应力和位移的边界、连续性条件方程组的行列式进行牛顿迭代,得到各层的频率参数。将确定的各层厚度、材料参数值及由牛顿迭代得到的频率参数值代入公式,可以得出谐振频率为1.453 8GHz。采用ADS对具有与公式计算相同厚度、材料的FBAR进行纵向振动Mason模型等效电路仿真,得到仿真模型的谐振频率为1.463GHz。仿真验证结果表明,谐振频率公式计算值和模型仿真值较近,可采用频率公式计算L波段FBAR纵波谐振频率。 相似文献
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《Electronics letters》2006,42(1):9
A low-power static frequency divider using an RTD/HBT MOnostable-BIstable transition Logic Element (MOBILE) scheme is proposed for the first time and operation of the circuit is demonstrated up to 20 GHz. The divided-by-two static frequency divider has been successfully implemented in an InP-based monolithic RTD/HBT IC technology. The number of devices used in the static frequency divider has been significantly reduced by using the proposed MOBILE scheme. The fabricated frequency divider operates at a clock frequency up to 20 GHz and dissipates d.c. power of 51 mW at a power supply of 3.3 V 相似文献
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讨论了锁相式频率合成器的基本原理,设计了一种通用可编程锁相式频率合成器,介绍了其编程置型格式,提出了一种可提高程控分频器工作频率的电路设计方法,并给出了其模拟波形。该电路的最高合成频率为100MHz最小频率间隔为100Hz,在工程上具有广泛的应用前景。 相似文献