频率覆盖

本文介绍用权电容编码方法展宽普通LC压控振荡器频率覆盖的原理和技术。

This paper describes the principle and method of expanding LC VCO frequency coverage by weighted capacitor-coding method .

通过VHF超宽频带CMOSLCVCO的具体设计表明，新电路结构可以获得突破性的频率覆盖。

The design example of a VHF CMOS LC VCO demonstrates that the new schematic can get a breakthrough in the tuning range performance .

其中输出杂散较大和频率覆盖带宽小一直是制约传统DDS进一步发展及应用的主要因素，单一的DDS合成技术无法同时满足带宽大和杂散小的要求。

These are the main factors that restraint the further development and application of the traditional DDS ' s. Single DDS synthesis technology can not satisfy the requirements of large bandwidth and small spurious .

由于天文和深空探测的需求，决定了VLBI的发展方向为实时性、高灵敏度、高可靠性和更宽的频率覆盖，这对VLBI设备提出了新的要求。

With the further development on the Astronomy and navigation of interplanetary spacecraft , the incremental improvements are expected on the VLBI that is real-time , high sensitivity , reliability and more frequency coverage .

任意波形的频率覆盖范围为1Hz~500KHz。

SWIFT waveform frequency ranged for 1Hz ~ 500 KHz .

频率覆盖范围0.1~20kHz。

It covers frequency range 0.1 ~ 20 kHz .

四色问题反例研究与民航空域频率覆盖

Research on Counterexamples of 4-colored Problem and Frequency Covering on Civil Aviation 's Airspace

高速、低电压、宽的频率覆盖范围是本设计的难点所在。

High speed , low supply voltage and wide frequency range are difficult problems in this design .

因此，接收机通常要求具有较宽的频率覆盖范围、实时信号处理能力、同时到达信号精确检测等性能。

So receiver with perfect performances is required , such as wider frequency covering domain , real time signal processing , exact detecting for simultaneous arriving signals , and so on .

在雷达侦察接收机的设计中，一般要具有瞬时宽带频率覆盖、高的灵敏度和动态范围、检测同时到达信号，以及高的测频精度和频率分辨率等性能要求。

In the design of radar reconnaissance receiver , generally have the characteristics including broadband instantaneous frequency coverage , good sensitivity and dynamic range , simultaneous signal detection , and fine frequency measurement .

对于全圆周天线而言，与Y形天线阵结构相比，在同样的空间频率覆盖范围内，全圆周天线阵使天线单元数达到了最优。

For the full-circle case , the array can be thinned up to the least redundant number , which can never be reached by the most popular Y shaped array configuration under same spatial frequency coverage constraint .

增大子孔径的直径可以增大空间频率覆盖程度，但子孔径直径过大时又会产生空间频率冗余度和增加制造成本。

The bigger the diameter of sub-aperture is , the more complete the spatial frequency covers . But when the ratio exceeds some extent , the spatial frequencies will be redundant and cost of system construction will increase .

其次给出了当发射或者接收信号频率覆盖范围较宽时，阵列采用移相器移相加权所带来的问题，进行了仿真实验并对仿真结果进行了分析。

Secondly , analyzed some problems of using phase-shifter for controlling the array , under the condition that the transmit signals and receive signals with wide frequency coverage , at last conducted some simulation experiments and given analysis of simulation results . 2 .

正弦波输出，失真小，稳定性好，频率范围覆盖整个音频范围。

Sine wave output , low distortion and high stability , frequency range over with whole audio range .

电子除垢是产生一个快速变化的电流，其变化频率范围覆盖了估计的水的固有频率。

Electronic descaler is one that creates a rapidly alternating current in a frequency range that exceeds the best estimate of the internal natural frequency of water .

结合现场实际情况，采用波谱能量分析方法和频率特性覆盖方法，确定了系统的加权函数阵；

Based on the features of oilfield , the spectrum energy analysis and frequency property coverage methods were used to determine the weight function matrix of the system .

现代战争环境中，信号频率的覆盖范围广（0-18GHz），信号参数多变，信号形式也日益复杂，有频率捷变，脉冲压缩，跳频扩频等多种信号形式。

In modern warfare environment , the signal frequency coverage becomes wider ( from2GHz to18GHz ) and the signal parameters and forms change more complex ( frequency agility , pulse compression , frequency hopping and spread spectrum ) .

文章着重分析了2.4GHz频段WLAN在热点地区应用时所特别涉及的无线网络规划问题，包括频率规划、覆盖范围、功率选择、干扰避免和小区复用等问题。

This paper focuses on the wireless network planning of WLAN at 2.4 GHz at hot spots , and including frequency planning , coverage planning , power planning , interference avoidance and cell multiplexing .

结果表明：我国冰害事故具有持续时间长、发生频率高、覆盖面积大等特点；

The results show that the ice accidents occurring in China have such characteristics as long duration , high frequency of occurrences , large coverage area and great loss to national economy , etc.

汉语存在句主要用于表达人类对存在认知的成果，描摹客观世界，使用频率高，覆盖范围广，是现代汉语的一种重要句型。

Chinese existential construction is mainly used to express the existence of human cognitive achievements , describe the objective world , the use of high frequency , covering a wide range of modern Chinese an important sentence .

LEO卫星通信网络具有高带宽、低链路损耗、较小的星地时延、频率复用以及全球覆盖等优点。

LEO satellite communications network has the advantages of high bandwidth , low link loss , short delay , global coverage and frequency-mutiple .

它能产生所有频率的声音，覆盖了整个人类的听力范围。

The unit generates noise at all frequencies across the human hearing range .

但是DDS采用全数字化结构，使其输出频率较低，绝对频率覆盖小，输出杂散较大。

However , DDS is a full digital structure , which leads to low frequency , narrow absolute frequency coverage , and large spurious with its output .

数字辅助的频率校准电路能够使滤波器的截止频率保持恒定，覆盖了芯片由于工艺、电压、温度变化而造成的频率偏差。

The digital-assisted frequency tuning scheme can remain the cutoff frequency constant with the variation of process , voltage and temperature .

实践证明，它频率稳定度高，其数量级与晶振相同，频率覆盖范围大，超过了倍频程，频率切换迅速，转换时间达微秒级。

Its hardware shows that the level of its frequency stability is the same as that of crystal oscillator , its frequency range covers over double frequency course and the time of frequency conversion is fast and is on the level of μ s.

本文首先说明了战场频率分配的重要性，并描述了战场的频率环境，在覆盖预测中加入了地形、地貌所产生的影响，使其适用于战场通信网络。

The intelligent optimization algorithms were given to solve battlefield frequency planning in this paper . First , this thesis describes the importance of the battlefield frequency allocation and frequency environment that joined the impact of terrain in the coverage prediction .