FCC E7F - 实用射频电路与滤波器

#E7F01🔗

What is meant by “direct sampling” in software defined radios?

软件定义无线电中的“直接采样”是什么意思？

Software is converted from source code to object code during operation of the receiver

在接收器操作期间软件从源代码转换为目标代码

I and Q signals are generated by digital processing without the use of RF amplification

I 和 Q 信号通过数字处理生成，无需使用 RF 放大

Incoming RF is digitized by an analog -to-digital converter without being mixed with a local oscillator signal

输入射频由模数转换器数字化，不会与本地振荡器信号混合

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A switching mixer is used to generate I and Q signals directly from the RF input

开关混频器用于直接从 RF 输入生成 I 和 Q 信号

#E7F02🔗

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

使用哪种数字信号处理音频滤波器来消除接收到的 SSB 信号中不需要的噪声？

An adaptive filter

自适应滤波器

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A crystal-lattice filter

晶格滤波器

A Hilbert-transform filter

希尔伯特变换滤波器

A phase-inverting filter

反相滤波器

#E7F03🔗

What type of digital signal processing filter is used to generate an SSB signal?

使用什么类型的数字信号处理滤波器来生成 SSB 信号？

An adaptive filter

自适应滤波器

A notch filter

陷波滤波器

A Hilbert - transform filter

希尔伯特变换滤波器

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An elliptical filter

椭圆形滤波器

#E7F04🔗

Which method generates an SSB signal using digital signal processing?

哪种方法使用数字信号处理生成 SSB 信号？

Mixing products are converted to voltages and subtracted by adder circuits

混合结果转换为电压并由加法器电路减去

A frequency synthesizer removes unwanted sidebands

频率合成器消除不需要的边带

Varying quartz crystal characteristics are emulated in digital form

以数字形式模拟不同的石英晶体特性

Signals are combined in quadrature phase relationship

信号以正交相位关系组合

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#E7F05🔗

How frequently must an analog signal be sampled to be accurately reproduced?

模拟信号必须多久采样一次才能准确再现？

At least half the rate of the highest frequency component of the signal

至少是信号最高频率分量速率的一半

At least twice the rate of the highest frequency component of the signal

至少是信号最高频率分量速率的两倍

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At the same rate as the highest frequency component of the signal

与信号的最高频率分量相同的速率

At four times the rate of the highest frequency component of the signal

信号最高频率分量速率的四倍

#E7F06🔗

What is the minimum number of bits required to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

以 1 毫伏的分辨率对 1 伏范围内的信号进行采样所需的最小位数是多少？

4 bits

4位

6 bits

6位

8 bits

8位

10 bits

10位

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#E7F07🔗

What function is performed by a Fast Fourier Transform?

快速傅立叶变换执行什么功能？

Converting analog signals to digital form

将模拟信号转换为数字形式

Converting digital signals to analog form

将数字信号转换为模拟形式

Converting signals from the time domain to the frequency domain

将信号从时域转换到频域

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Converting signals from the frequency domain to the time domain

将信号从频域转换到时域

#E7F08🔗

What is the function of decimation?

抽取的作用是什么？

Converting data to binary-coded decimal form

将数据转换为二进制编码的十进制形式

Reducing the effective sample rate by removing samples

通过移除样本来降低有效采样率

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Attenuating the signal

衰减信号

Removing unnecessary significant digits

删除不必要的有效数字

#E7F09🔗

Why is an anti-aliasing filter required in a decimator?

为什么抽取器中需要抗混叠滤波器？

It removes high -frequency signal components that would otherwise be reproduced as lower frequency components

它消除了高频信号分量，否则这些信号分量将被再现为低频分量

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It peaks the response of the decimator, improving bandwidth

它使抽取器的响应达到峰值，从而提高带宽

It removes low-frequency signal components to eliminate the need for DC restoration

它消除了低频信号分量，从而无需进行直流恢复

It notches out the sampling frequency to avoid sampling errors

它降低采样频率以避免采样错误

#E7F10🔗

What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a direct-sampling software defined radio (SDR)?

接收器模数转换的哪个方面决定了直接采样软件定义无线电 (SDR) 的最大接收带宽？

Sample rate

采样率

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Sample width in bits

样本宽度（以位为单位）

Integral non-linearity

积分非线性

Differential non-linearity

微分非线性

#E7F11🔗

What sets the minimum detectable signal level for a direct-sampling software defined receiver in the absence of atmospheric or thermal noise?

在没有大气或热噪声的情况下，什么决定了直接采样软件定义的接收器的最小可检测信号电平？

Sample clock phase noise

采样时钟相位噪声

Reference voltage level and sample width in bits

参考电压电平和采样宽度（以位为单位）

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Data storage transfer rate

数据存储传输率

Missing codes and jitter

漏码和抖动

#E7F12🔗

Which of the following is generally true of Finite Impulse Response (FIR) filters?

以下哪项对于有限脉冲响应 (FIR) 滤波器来说通常是正确的？

FIR filters can delay all frequency components of the signal by the same amount

FIR 滤波器可以将信号的所有频率分量延迟相同的量

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FIR filters are easier to implement for a given set of passband rolloff requirements

对于一组给定的通带滚降要求，FIR 滤波器更容易实现

FIR filters can respond faster to impulses

FIR 滤波器可以更快地响应脉冲

All these choices are correct

所有这些选项都是正确的

#E7F13🔗

What is the function of taps in a digital signal processing filter?

数字信号处理滤波器中的抽头有何作用？

To reduce excess signal pressure levels

减少过多的信号压力水平

Provide access for debugging software

提供调试软件的访问权限

Select the point at which baseband signals are generated

选择生成基带信号的点

Provide incremental signal delays for filter algorithms

为滤波器算法提供增量信号延迟

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#E7F14🔗

Which of the following would allow a digital signal processing filter to create a sharper filter response?

以下哪项可以让数字信号处理滤波器产生更清晰的滤波器响应？

Higher data rate

更高的数据速率

More taps

更多水龙头

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Lower Q

降低Q值

Double-precision math routines

双精度数学例程

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FCC E7F - 实用射频电路与滤波器

小节 E7F：实用射频电路与滤波器