FCC E9E - 天线与传输线系统

#E9E01🔗

Which matching system for Yagi antennas requires the driven element to be insulated from the boom?

八木天线的哪种匹配系统要求驱动元件与吊杆绝缘？

Gamma

伽玛

Beta or hairpin

贝塔或发夹

✓ 正确答案

Shunt-fed

并联供电

T-match

T型比赛

#E9E02🔗

What antenna matching system matches coaxial cable to an antenna by connecting the shield to the center of the antenna and the conductor a fraction of a wavelength to one side?

什么天线匹配系统通过将屏蔽层连接到天线中心并将导体连接到一侧来将同轴电缆与天线匹配？

Gamma match

伽玛匹配

✓ 正确答案

Delta match

三角洲比赛

T-match

T型比赛

Stub match

存根匹配

#E9E03🔗

What matching system uses a short length of transmission line connected in parallel with the feed line at or near the feed point?

什么匹配系统使用与馈电点或馈电点附近的馈电线路并联的短传输线？

Gamma match

伽玛匹配

Delta match

三角洲比赛

T-match

T型比赛

Stub match

存根匹配

✓ 正确答案

#E9E04🔗

What is the purpose of the series capacitor in a gamma match?

伽玛匹配中串联电容器的用途是什么？

To provide DC isolation between the feed line and the antenna

在馈线和天线之间提供直流隔离

To cancel unwanted inductive reactance

消除不需要的感抗

✓ 正确答案

To provide a rejection notch that prevents the radiation of harmonics

提供抑制陷波以防止谐波辐射

To transform the antenna impedance to a higher value

将天线阻抗变换为更高的值

#E9E05🔗

What Yagi driven element feed point impedance is required to use a beta or hairpin matching system?

使用 beta 或发夹匹配系统需要多少八木驱动元件馈电点阻抗？

Capacitive (driven element electrically shorter than 1/2 wavelength)

电容式（驱动元件电气长度短于 1/2 波长）

✓ 正确答案

Inductive (driven element electrically longer than 1/2 wavelength)

电感式（驱动元件电气长度超过 1/2 波长）

Purely resistive

纯电阻式

Purely reactive

纯反应式

#E9E06🔗

Which of these transmission line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm feed point impedance to a 50-ohm transmission line?

这些传输线阻抗中的哪一个适合构建四分之一波 Q 截面，以将 100 欧姆馈电点阻抗与 50 欧姆传输线相匹配？

50 ohms

50欧姆

62 ohms

62欧姆

75 ohms

75欧姆

✓ 正确答案

90 ohms

90欧姆

#E9E07🔗

What parameter describes the interaction of a load and transmission line?

什么参数描述负载和传输线的相互作用？

Characteristic impedance

特性阻抗

Reflection coefficient

反射系数

✓ 正确答案

Velocity factor

速度系数

Dielectric constant

介电常数

#E9E08🔗

What is a use for a Wilkinson divider?

威尔金森分隔器有什么用？

To divide the operating frequency of a transmitter signal so it can be used on a lower frequency band

划分发射机信号的工作频率，以便可以在较低频段上使用

To feed high-impedance antennas from a low-impedance source

从低阻抗源向高阻抗天线供电

To divide power equally between two 50 - ohm loads while maintaining 50 - ohm input impedance

在两个 50 欧姆负载之间平均分配功率，同时保持 50 欧姆输入阻抗

✓ 正确答案

To divide the frequency of the input to a counter to increase its frequency range

对计数器的输入频率进行分频以增加其频率范围

#E9E09🔗

Which of the following is used to shunt feed a grounded tower at its base?

以下哪项用于为底部接地塔分路供电？

Double-bazooka match

双火箭筒比赛

Beta or hairpin match

Beta 或发夹匹配

Gamma match

伽玛匹配

✓ 正确答案

All these choices are correct

所有这些选项都是正确的

#E9E11🔗

What is the purpose of using multiple driven elements connected through phasing lines?

使用通过定相线连接的多个驱动元件的目的是什么？

To control the antenna’s radiation pattern

控制天线的辐射方向图

✓ 正确答案

To prevent harmonic radiation from the transmitter

防止发射机的谐波辐射

To allow single-band antennas to operate on other bands

允许单频段天线在其他频段工作

To create a low-angle radiation pattern

创建低角度辐射方向图

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FCC E9E - 天线与传输线系统

小节 E9E：天线与传输线系统