MX890120A Commercialization Proposal 手持式频谱分析仪MS2711B操作应用培训 2018/11/28

MX890120A Commercialization Proposal 内容 使用注意事项 仪表指标 频谱仪测量原理介绍 现场测试操作 测试注意事项 MS2711B操作面板介绍 1 2018/11/28 1

MX890120A Commercialization Proposal 使用注意事项 防静电及良好接地 输入信号不能超过烧毁电平 《 +23dBm(前置放大器关） 《 +13dBm(前置放大器开） 1 2018/11/28 1

MX890120A Commercialization Proposal 主要指标 频率 频率范围 100KHz~3GHz 参考频率 漂移 ±1ppm/一年 精度 ±2ppm 频宽 在1KHz~3GHz范围，步进为1、2、5，选择自动方式 扫描时间 全频段大于等于6.5秒；频宽为0时510ms 单边带相位噪声 -75dBc/Hz 偏离中心频率30KHz 分辨带宽 选择性 10KHz、30KHz、100KHz、1MHz 精度 ±20% 典型值 视频带宽 选择性 从100Hz到300KHz，步进为1-3序列频率： 100KHz~3GHz 分辨带宽： 1KHz~1MHz 2018/11/28

MX890120A Commercialization Proposal 主要指标 幅度 测量范围 +20dBm到--115dBm（不带选件） 最大输入电平 +23dBm ±50VDC 显示平均噪声电平 ≤-115 dBm（打开预放，≥1MHz的典型值） ≤-95 dBm（关闭预放，≥500KHz的典型值） ≤-80 dBm（关闭预放，<500KHz的典型值） 动态范围 >65 dB 整机电平精度 ±2 dB ≥500 KHz的典型值* 幅度单位 对数刻度方式 dBm/m，dBV/m，dBmV/m，dBµV/m 显示范围 2-15 dB/每格，步进1 dB，显示10格 衰减器 0-50 dB， 手动或自动， 分辨率为10 dB步进 Slide 6 Now that we understand why spectrum analyzers are important, let's take a look at the different types of analyzers available for measuring RF. There are basically two ways to make frequency domain measurements (what we call spectrum analysis): Fourier transform and swept-tuned. The Fourier analyzer basically takes a time-domain signal, digitizes it using digital sampling, and then performs the mathematics required to convert it to the frequency domain*, and display the resulting spectrum. It is as if the analyzer is looking at the entire frequency range at the same time using parallel filters measuring simultaneously. It is actually capturing the time domain information which contains all the frequency information in it. With its real-time signal analysis capability, the Fourier analyzer is able to capture periodic as well as random and transient events. It also can provide significant speed improvement over the more traditional swept analyzer and can measure phase as well as magnitude. However it does have its limitations, particularly in the areas of frequency range, sensitivity, and dynamic range. We shall discuss what these terms are and why they are important in a later section. Fourier analyzers are becoming more prevalent, as analog-to-digital converters (ADC) and digital signal processing (DSP) technologies advance. Operations that once required a lot of custom, power-hungry discrete hardware can now be performed with commercial off-the-shelf DSP chips, which get smaller and faster every year. These analyzers can offer significant performance improvements over conventional spectrum analyzers, but often with a price premium. * The frequency domain is related to the time domain by a body of knowledge generally known as Fourier theory (named for Jean Baptiste Joseph Fourier, 1768-1830). Discrete, or digitized signals can be transformed into the frequency domain using the discrete Fourier transform. 2018/11/28

MX890120A Commercialization Proposal 频谱仪构造框图说明 射频输入衰减器 中频滤波器 中频放大器 检波器 混频器 输入射频信号 Pre-Selector Or Low Pass Filter 对数放大器 视频滤波器 本地振荡器 锯齿波扫平器 Slide 9 The major components in a spectrum analyzer are the RF input attenuator, mixer, IF (Intermediate Frequency) gain, IF filter, detector, video filter, local oscillator, sweep generator, and LCD display. Before we talk about how these pieces work together, let's get a fundamental understanding of each component individually. 参考振荡器 屏幕显示 2018/11/28

MX890120A Commercialization Proposal 通过变频得到想要的信号 --混频器 fLO-fin fLO+fin fLO 3 Input signal displayed fLO - fin = fIF fif fin Range 1 fin fin LO LO Range 2 4 显示结果 2018/11/28

MX890120A Commercialization Proposal 分辨率带宽RBW对信号和噪声的影响 2018/11/28

MX890120A Commercialization Proposal 实现各种模式的精确采样 --检波器 检波器 输入信号 幅度 正峰值采样: largest value in bin displayed "bins" 负峰值采样: smallest value in bin displayed Slide 12 The analyzer must covert the IF signal to a baseband or video signal so it can be digitized and then viewed on the analyzer display. This is accomplished with an envelope detector whose video output is then digitized with an analog-to-digital converter (ADC). The digitized output of the ADC is then represented as the signal’s amplitude on the Y-axis of the display. This allows for several different detector modes that dramatically affect how the signal is displayed. In positive detection mode, we take the peak value of the signal over the duration of one trace element, whereas in negative detection mode, its the minimum value. Positive detection mode is typically used when analyzing sinusoids, but is not good for displaying noise, since it will not show the true randomness of the noise. In sample detection, a random value for each bin is produced. This is best for looking at noise or noise-like signals. For burst or narrowband signals, it is not a good mode to use, as the analyzer might miss the signals of interest. When displaying both signals and noise, the best mode is the normal mode, or the rosenfell mode. This is a "smart" mode, which will dynamically change depending upon the input signal. For example, If the signal both rose and fell within a sampling bin, it assumes it is noise and will use pos & neg det alternately. If it continues to rise, it assumes a signal and uses pos peak det. 平均值采样: last value in bin displayed 2018/11/28

检波方式: Pos Peak,Neg Peak,Sample MX890120A Commercialization Proposal 检波方式: Pos Peak,Neg Peak,Sample Pos Peak Neg Peak Sample 采样点 频谱显示 2018/11/28

MX890120A Commercialization Proposal 频谱仪分辨率对测量的影响 3 dB Mixer Detector 3 dB BW 输入信号 中频滤波器/ 分辨率带宽 (RBW) LO Sweep Slide 29 One of the first things to note is that a signal cannot be displayed as an infinitely narrow line. It has some width associated with it. This shape is the analyzer's tracing of its own IF filter shape as it tunes past a signal. Thus, if we change the filter bandwidth, we change the width of the displayed response. Agilent datasheets specify the 3 dB bandwidth. Some other manufacturers specify the 6 dB bandwidth. This concept enforces the idea that it is the IF filter bandwidth and shape that determines the resolvability between signals. RBW Display . 2018/11/28

MX890120A Commercialization Proposal 频谱仪分辨率对动态范围的影响 --RBW设置与动态范围 噪声电平改变量 (dB) = 10 log(RBW新)/(RBW旧) 100 kHz RBW 10 dB 10 kHz RBW 10 dB 1 kHz RBW Slide 43 This internally generated noise in a spectrum analyzer is thermal in nature; that is, it is random and has no discrete spectral components. Also, its level is flat over a frequency range that is wide in comparison to the ranges of the RBWs. This means that the total noise reaching the detector (and displayed) is related to the RBW selected. Since the noise is random, it is added on a power basis, so the relationship between displayed noise level and RBW is a ten log basis. In other words, if the RBW is increased (or decreased) by a factor of ten, ten times more (or less) noise energy hits the detector and the displayed average noise level (DANL) increases (or decreases) by 10 dB. The relationship between displayed noise level and RBW is: noise level change (dB) = 10 log(RBWnew)/(RBWold) Therefore, changing the RBW from 100 kHz (RBWold) to 10 kHz (RBWnew) results in a change of noise level: noise level change = 10 log (10 kHz/100 kHz) = - 10 dB. Spectrum analyzer noise is specified in a specific RBW. The spectrum analyzer's lowest noise level (and slowest sweeptime) is achieved with its narrowest RBW. 减小RBW = 降低噪声 2018/11/28

MS2711B现场测试操作

MX890120A Commercialization Proposal 1、用频谱分析仪作放大器增益测试 接收机 源 Repeater 频谱仪 RF in CRT Display IF LO Repeater Slide 75 Stimulus response measurements, which are also called network measurements, is where we apply a signal to the input of our device/system and measure the response at the output. So we require a source and a receiver The transfer characteristics we can measure include frequency response, return loss, conversion loss, and gain versus frequency. There are two major instruments that are capable of making stimulus-response measurements. A network analyzer and a spectrum analyzer. You will learn about using a network analyzer in great detail in the NA Basics paper To use a spectrum analyzer for making stimulus-response measurements, a tracking generator must be used. A tracking generator is typically built into the spectrum analyzer and provides the source. It is a sinusoidal output whose frequency is the same as the analyzer's input frequency, so it follows (tracks) the tuning of the spectrum analyzer. The output of the tracking generator (source) is connected to the input of the DUT and the response is measured by the analyzer (receiver). As the analyzer sweeps, the tracking generator will always be operating at the same frequency so the transfer characteristics of your device can be measured. TG out Tracking Adjust Tracking Generator 2018/11/28

MX890120A Commercialization Proposal 1、用频谱分析仪作放大器增益测试 1、复位MS2711B，进入出厂默认值。 2、按MODE键，选择TRACKING GENERATOR，按ENTER确认。 3、用一根测试电缆连接频谱仪的RF输入口和输出口。 4、按FREQ/SPAN选择CENTER，输入中心频率。 5、按SPAN，设置测试带宽。 6、按BW/SWEEP，设置为AUTO。 7、按AMPLITUDE，选择参考电平，设为0dBm。 8、按ATTEN，设置为AUTO。 9、按AMPLITUDE，设置TG OUTPUT LEVEL为0dBm。 10、测试数据的线迹应该是显示在顶部的一条直线。 11、按“8” 键，记录RL=标记点电平的绝对值。 11、按AMPLITUDE调整REF LEVEL OFFSET，即RL offset=RL。在显示器上获得容易观察的图形。 12、按上图连接好衰减器和测试线缆，按“8” 键，记录增益G=标记点电平值-TG设置电平+外置衰减器值。 Slide 75 Stimulus response measurements, which are also called network measurements, is where we apply a signal to the input of our device/system and measure the response at the output. So we require a source and a receiver The transfer characteristics we can measure include frequency response, return loss, conversion loss, and gain versus frequency. There are two major instruments that are capable of making stimulus-response measurements. A network analyzer and a spectrum analyzer. You will learn about using a network analyzer in great detail in the NA Basics paper To use a spectrum analyzer for making stimulus-response measurements, a tracking generator must be used. A tracking generator is typically built into the spectrum analyzer and provides the source. It is a sinusoidal output whose frequency is the same as the analyzer's input frequency, so it follows (tracks) the tuning of the spectrum analyzer. The output of the tracking generator (source) is connected to the input of the DUT and the response is measured by the analyzer (receiver). As the analyzer sweeps, the tracking generator will always be operating at the same frequency so the transfer characteristics of your device can be measured. 2018/11/28

MX890120A Commercialization Proposal 2、用频谱分析仪作信号强度测试 接收机 源 Repeater 频谱仪 Repeater CRT Display IF LO 2018/11/28

MX890120A Commercialization Proposal 2、用频谱分析仪作信号强度测试 1、复位MS2711B，进入出厂默认值。 2、按MODE键，选择SPECTRUM ANALYZER，进入频谱分析仪模式，按ENTER确认。 3、按FREQ/SPAN选择CENTER，输入中心频率。 4、按SPAN，设置测试带宽。 5、按BW/SWEEP，设置RBW为30KHz，VBW为300Hz。 6、按AMPLITUDE，选择参考电平。 7、按ATTEN，设置为AUTO。 8、按上图连接好衰减器和测试线缆，按“8” 键，选择测试的标记点，并记录该点的信号强度。 2018/11/28

MX890120A Commercialization Proposal 3、用频谱分析仪作宽带信道功率测试 接收机 源 Repeater 频谱仪 Repeater CRT Display IF LO 2018/11/28

MX890120A Commercialization Proposal 3、用频谱分析仪作宽带信道功率测试 1、复位MS2711B，进入出厂默认值。 2、按MODE键，选择SPECTRUM ANALYZER，进入频谱分析仪模式，按ENTER确认。 3、按FREQ/SPAN选择CENTER，输入中心频率。 4、按SPAN，设置测试带宽。 5、按BW/SWEEP，设置RBW为10KHz，VBW为30KHz。 6、按AMPLITUDE，选择参考电平。 7、按ATTEN，设置为AUTO。 8、按MEAS键选择CHANNEL POWER软键。 9、选择CENTER FREQ软键，设置宽带信号的中心频率。 10、选择INT BW软键设置测试带宽为1.23MHz或3.84MHz。 11、开始测量功能可通过按MEASURE ON/OFF软键来完成。测量检波方式会自动被设置为平均值检波方式。显示于屏幕上的两根垂直实线可以左右平移来显示它们整个频率带宽。MS2711B频谱议会在屏幕上显示测量结果。 2018/11/28

MX890120A Commercialization Proposal MS2711B测试注意事项 1 2018/11/28 1

MX890120A Commercialization Proposal MS2711B测试注意事项 1、分辨率设置 作为一个常用的规则，频谱仪测量所选的VBW与RBW的比例因子为10到100，这样，对分辨带宽设为30KHz时，VBW的典型选择是3KHz或300Hz。 记住，分辨带宽必须小于或等于两个信号的频率间隔。 2、分辨率设置与频谱仪扫描速度的关系 当改变RBW和VBW时，扫频速度也随着改变。RBW和VBW的值越大，扫描速度越快，RBW和VBW的值越小，扫描速度越慢。 3、对于前置放大器的使用 在使用频谱仪前，应确定是否已关闭前置放大器，避免因输入信号功率过强而损坏前置放大器。 要求输入信号小于或等于-50dBm，才使用前置放大器。 1 2018/11/28 1

MX890120A Commercialization Proposal MS2711B操作面板介绍 1 2018/11/28 1

MX890120A Commercialization Proposal 显示 标题区 工作方式 菜单区 现在菜单，通过软键选择 信息区 设置 图形区 测量数据 2018/11/28

MX890120A Commercialization Proposal 显示 2018/11/28

MX890120A Commercialization Proposal 测试接头 DC输入／电池充电输入 12.5 ~ 15 Vdc @ 1100mA ！！！充电时，必须接地良好，否则外部电脉冲信号将烧毁仪表！！！ 电池充电指示灯 外部电源指示灯 耳机插孔 串行接口 射频输入 射频输出 射频检测 电池盒盖板 2018/11/28

MX890120A Commercialization Proposal 前面板操作功能 软键（Soft Keys) 功能键（Function Hard Keys) 键区键（Keypad Hard Keys) 2018/11/28

MX890120A Commercialization Proposal 前面板操作 -- 软键(Soft Keys) 6个 - 分别对应六个相应的弹出软键。 2018/11/28

前面板操作 -- 功能键（Function Hard Keys) MX890120A Commercialization Proposal 前面板操作 -- 功能键（Function Hard Keys) 功能键(Function Hard Keys) 4个 工作方式(MODE) 频率/宽度(FREQ/SPAN) 幅度(AMPLITUDE) 带宽/扫描(BW/SWEEP) 2018/11/28

MX890120A Commercialization Proposal 前面板操作 -- 工作方式(Mode) 工作方式(MODE) 频谱分析 可用于测试信号覆盖强度，信源的选择判断，干扰源的查找。 跟踪信号源操作 快速跟踪信号源操作 测试放大器的增益，器件的传输测量。 2018/11/28

频谱分析模式 -- 频率/宽度(FREQ/SPAN) MX890120A Commercialization Proposal 频谱分析模式 -- 频率/宽度(FREQ/SPAN) 中心频率 起始频率 结束频率 频宽 频率单位 全频段 零频段 2018/11/28

频谱分析模式 -- 幅度(AMPLITUDE) MX890120A Commercialization Proposal 频谱分析模式 -- 幅度(AMPLITUDE) 参考电平 幅度 衰减 单位 2018/11/28

频谱分析模式 -- 带宽/扫描(BW/SWEEP) MX890120A Commercialization Proposal 频谱分析模式 -- 带宽/扫描(BW/SWEEP) 分辨率带宽 视频带宽 最大保持 检测方式 平均方式 检波方式 正峰值检波,平均,负峰值检波 2018/11/28

跟踪信号源操作模式 -- 频率/宽度(FREQ/SPAN) MX890120A Commercialization Proposal 跟踪信号源操作模式 -- 频率/宽度(FREQ/SPAN) 跟踪信号源偏移量 全频段 零频段 频段扩大 频段缩小 2018/11/28

跟踪信号源操作模式 -- 幅度(AMPLITUDE) MX890120A Commercialization Proposal 跟踪信号源操作模式 -- 幅度(AMPLITUDE) 跟踪信号源输出电平 衰减（自动,手动） 2018/11/28

跟踪信号源操作模式 -- 带宽/扫描(BW/SWEEP) MX890120A Commercialization Proposal 跟踪信号源操作模式 -- 带宽/扫描(BW/SWEEP) 分辨率带宽 视频带宽 最大保持 平均次数 监测方式 2018/11/28

MX890120A Commercialization Proposal 快速跟踪信号源操作模式 所有菜单同跟踪信号源操作模式 2018/11/28

前面板操作 -- 键区键(Keypad Hard Keys) MX890120A Commercialization Proposal 前面板操作 -- 键区键(Keypad Hard Keys) 键区键（Keypad Hard Keys) 17 个 “1”/ 背景灯 “2”/ 对比度 “3”/ 曲线(TRACE) “4”/ 测量(MEAS) “5”/ 存储设置(SAVE SETUP) “6”/ 调用设置(RECALL SETUP) “7”/ 极限线(LIMIT) “8”/ 标记(MARKER) “9”/ 存储显示(SAVE DISPLAY) “0”/ 调用显示(RECALL DISPLAY) 2018/11/28

前面板操作 -- 键区键(Keypad Hard Keys) MX890120A Commercialization Proposal 前面板操作 -- 键区键(Keypad Hard Keys) 键区键（Keypad Hard Keys) 17 个 电源开关(ON/OFF) 打印键(PRINT) 退出／清除键(ESCAPE/CLEAR)   上下键 回车确认键(ENTER) 单次／连续／符号  键(SINGLE/CONT/+/-) 系统功能键(SYSTEM) – 见后说明 2018/11/28

MX890120A Commercialization Proposal 前面板操作 -- 曲线(TRACE) 曲线A 曲线切换 曲线B 重置曲线 2018/11/28

MX890120A Commercialization Proposal 前面板操作 -- 测量(MEAS) 通道功率 场强测试 占频带宽 邻道功率比 前置放大 占频带宽测试 测量开关 AM/FM解调 2018/11/28

MX890120A Commercialization Proposal 前面板操作 -- 极限线(LIMIT) 单极限线 多极限线（上） 多极限线（下） 极限线报警 极限线分段 2018/11/28

MX890120A Commercialization Proposal 前面板操作 -- 标记(MARKER) 标记（共6个） 峰值标记 中心频率标记 标记编辑 2018/11/28

前面板操作 -- 系统功能键(SYSTEM) MX890120A Commercialization Proposal 前面板操作 -- 系统功能键(SYSTEM) 系统选项 系统自检 阻抗匹配选项 语言选项 打印选项 时钟选项 2018/11/28

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