相对带宽

给出了工作在C波段、相对带宽为5%的1-40的大型功分馈电网络的具体实现过程。

In this paper a C-band feeding circuit with 5 % relative bandwidth is realized .

由于相对带宽很大，与窄带系统相比，宽带SAR系统误差对成像的影响更严重。

On account of the wide relative bandwidth , compared with the narrow-band system , large-band SAR system errors impose more severe effect on imaging quality .

本文报道了对时带宽积为160，相对带宽为3%的幂级数调频SAW色散线的研究结果。

In this article some results about the study of a SAW power series FM DL ( PFM DL ) with time bandwidth product of 160 and fractional bandwidth of 32 % are presented .

穿透叶簇的VHF/UHF超宽带（UWB）SAR具有相对带宽很宽，积累角大的特点，能同时获得距离、方位两个方向的高分辨能力，用于探测地面隐蔽人造目标。

Foliage penetrating ( FOPEN ) VHF / UHF SAR can image hidden man-made targets with wide-angle and ultra-wideband to achieve both range and azimuth with high resolutions .

经过众多研究人员的不懈努力，微带天线的相对带宽已经从最初的7%扩展到60%-70%，许多UWB天线的相对带宽已经可以超过100%。

Through the efforts of many researchers , the bandwidth of the microstrip antenna has been expanded from 7 % to 60 % or 70 % .

首先给出双截止组合型、F-P型、多半波型等几种膜系结构，归纳了相对带宽估算公式。

Several film structures such as double cut-off structure , F-P structure , multi-half-wave structure are given , and their bandwidth estimation formulas are concluded .

滤波器基于镀有双面YBCO超导薄膜的蓝宝石基片设计，尺寸为47.54mm×18.12mm，中心频率为1940MHz，相对带宽为0.5%。

The filter with a 0.5 % fractional bandwidth at 1940 MHz was designed on a 2-inch sapphire substrate which was double side coated with YBCO thin films .

提出了基于HHT的数字调制通信信号识别方法，提出了经验模式分解（EMD）主分量能量方差和希尔伯特边际谱相对带宽这两个特征参数。

A digital modulation signal classification method based on the Hilbert-Huang transform is presented . Two characteristic parameters , the energy variance of the EMD 's main component and the relative bandwidth of the Hilbert marginal spectrum are proposed .

在外电路匹配条件下，插损4dB，相对带宽0.06%左右。

On condition of outer matched circuit , the filter is featured with insertion loss of 4 dB , fractional bandwidth of about 0.06 % .

实测结果表明：在2.4GHz频段上，1和2天线分别获得了12.24%和16.33%的相对带宽（VSWR≤2）。

Measured results show that the 1 # antenna has a bandwidth of 12.24 % centered at 2.4GHz ( VSWR ≤ 2 ), and the 2 # 16.33 % respectively .

利用微波仿真软件HFSS进行仿真，结果表明天线2个端口的驻波比小于2的相对带宽均达到12.5%；在工作频带内其双端口隔离度S21高于48dB；

The HFSS results show that the bandwidths of VSWR < 2 reaches 12.5 % in both ports , and the isolation between the excitation ports is greater than 48 dB over this frequency range .

在中高信噪比、快拍数较多、相对带宽小于5%时，MDL算法可以很好地估计信源的个数。

When the number of snapshots is enough and the relative bandwidth of the signals are all less than 5 % , MDL algorithm can accurately estimate the number of sources at moderate or high signal-to-noise ratio ( SNR ) .

扩频接收机中带通滤波器最优相对带宽分析

Analysis of the Band-pass Filter 's Optimum Relative Bandwidth in Spread-Spectrum Receivers

说明了相对带宽对光子晶体设计的重要性。

The importance of relative bandwidth to the design of photonic crystal is described .

不同的脉冲对系统允许发射的最大功率、系统的抗多径衰落性能等有很大的影响。本文研究了脉冲的带宽和相对带宽对系统的抗多径衰落性能的影响。

The influence of the bandwidth and fractional bandwidth of baseband pulse on multi-path fading was simulated .

这种天线驻波比小于2.5的相对带宽超过100%；

The relative bandwidth of the antenna with input voltage standing wave ratio less than 2.5 exceeds 100 % .

超宽带信号是就信号的相对带宽而言，当信号的带宽与中心频率之比大于25%时称为超宽带信号。

A signal is called an Ultra-band signal ( UWB ) if its ratio of bandwidth to center-frequency exceeds 25 % .

结果表明，增大相对带宽是提高散射中心类型参数估计精度的有效手段；

Results show that increasing relative bandwidth is the most effective way to improve the estimation accuracy of the type parameter .

文中用该方法设计了一个中心频率为10.37GHz，相对带宽21.7%的宽带微带天线，得到了较好的参数。

Paper designs a microstrip antenna whose centric frequency is 10.37 GHz and relative bandwidth is 20.7 % , have received better parameter .

由于在设计过程中耦合器的带宽是相对带宽，因此根据归一化频率选择的不同，基本上能实现任意频率范围的耦合器。

Because of the related bandwidth in the design process , coupler with arbitrary frequency domain can be designed according to the different choice of normalizing frequency .

针对多半波结构，提出了间隔层膜料和光学厚度的选择、采用等效膜、调整膜层折射率等相对带宽调整的方法。

Relative bandwidth adjustment methods are put forward , such as using interval layer material , selecting optical thickness , using equivalent film , adjusting film refractive index .

当发射端滤波器相对带宽大于等于0.8时，接收端滤波器最优相对带宽与发射端滤波器相对带宽无关。

When the filter relative bandwidth of the transmitters is not less than 0.8 , the optimum relative bandwidth in the receivers is independent of the band-pass filter 's bandwidth of transmitters .

文章列举了几组滤波器的实测结果，其中一组在不加任何特别措施的情况下，相对带宽作到了27%，另有一组具有明显的带外衰减极点。

Some experimental results for the filters are given , one has bandwidth of 27 % without special measure employed , and another has two evident attenuation poles on either side of the passband .

若透射率在1%以下为光子晶体禁带，则禁带波长范围从331.2~350.4nm，相对带宽5.63%。

If transmissivity is below 1 % , it is photonic crystal forbidden band , the wavelength range of the forbidden band is 331.2 ~ 350.4 nm , the relative bandwidth is 5.63 % .

最优相对带宽与输入载噪比、中心频率及相关积分时间无关，但受收发两端滤波器类型影响；

The optimum relative bandwidth is independent of the input carrier-to-noise ratio , center frequency and correlative integral time . But it is affected by the filter ′ s type in both transmitters and receivers .

研究结果表明，接收端带通滤波器存在最优相对带宽使得检波前信噪比最大，并且最优带宽不等于信号带宽；

Through numerical analysis , it is proved that there is an optimum relative bandwidth of this bandpass filter which maximizes the SNR before detection and which is not equal to the bandwidth of the signal .

特别是第一级带通滤波电路为新颖的紧凑型结构设计，其相对带宽小于8%，带内插损小，并有对称的可调传输零点对，可有效抑制谐波并减小电路尺寸。

A novel compact structure of band pass filter is specially introduced . The relative bandwidth is less than 8 % , low insertion loss in pass band and symmetric couple of transmission zeros achieved high selectivity .

其驻波比小于2的相对带宽超过51%，充分显示了此类单极子天线良好的宽频带特性。

The simulated and experimental results have demonstrated that the proposed monopole can achieve more than 51 % frequency band with the VSWR less than 2 . The relative bandwidth shows the good electrical characteristics of this kind of monopole .

仿真结果表明，该天线在驻波比小于2时的相对带宽可达75.5%，在整个频带内的平均增益为7.31dBi，而且，方向图和增益随频率变化较平稳。

It is indicated that the bandwidth ( VSWR ≤ 2 ) of the antenna reaches 75.5 % and the average gain over the whole bandwidth is 7.31 dBi . Moreover , the antenna has the characteristics of stable variation of the gain and radiation patterns .

以梳状线带通滤波器为例，通过计算几个典型的归一化杆径和归一化间距，绘制出分别以相对带宽为横坐标，归一化杆径和归一化间距为纵坐标的快速简便的设计曲线。

Taking pectinate bandpass filter for example , by calculating some typical normalized diameters and spaces between of poles , a fast and simple design curves is obtained in which , X-coordinate is for relative wideband , Y-coordinate is for normalized diameter and space between of pole respectively .