FCC E9A - 天线与传输线系统

#E9A01🔗

What is an isotropic radiator?

什么是各向同性散热器？

A calibrated, unidirectional antenna used to make precise antenna gain measurements

用于进行精确天线增益测量的已校准单向天线

An omnidirectional, horizontally polarized, precisely calibrated antenna used to make field measurements of antenna gain

全向、水平极化、精确校准的天线，用于对天线增益进行现场测量

A hypothetical , lossless antenna having equal radiation intensity in all directions used as a reference for antenna gain

假设的无损天线在所有方向上具有相同的辐射强度，用作天线增益的参考。

✓ 正确答案

A spacecraft antenna used to direct signals toward Earth

用于将信号引导至地球的航天器天线

#E9A02🔗

What is the effective radiated power (ERP) of a repeater station with 150 watts transmitter power output, 2 dB feed line loss, 2.2 dB duplexer loss, and 7 dBd antenna gain?

发射机功率输出为 150 瓦、馈线损耗为 2 dB、双工器损耗为 2.2 dB、天线增益为 7 dBd 的中继站的有效辐射功率 (ERP) 是多少？

469 watts

469瓦

78.7 watts

78.7瓦

420 watts

420瓦

286 watts

286瓦

✓ 正确答案

#E9A03🔗

What term describing total radiated power takes into account all gains and losses?

描述总辐射功率的哪个术语考虑了所有增益和损耗？

Power factor

功率因数

Half-power bandwidth

半功率带宽

Effective radiated power

有效辐射功率

✓ 正确答案

Apparent power

视在功率

#E9A04🔗

Which of the following factors affect the feed point impedance of an antenna?

以下哪些因素会影响天线的馈电点阻抗？

Transmission line length

传输线长度

Antenna height

天线高度

✓ 正确答案

The settings of an antenna tuner at the transmitter

发射机天线调谐器的设置

The input power level

输入功率电平

#E9A05🔗

What does the term “ground gain” mean?

“接地增益”一词是什么意思？

The change in signal strength caused by grounding the antenna

天线接地引起的信号强度变化

The gain of the antenna with respect to a dipole at ground level

天线相对于地面偶极子的增益

To force net gain to 0 dB by grounding part of the antenna

通过将天线部分接地将净增益强制为 0 dB

An increase in signal strength from ground reflections in the environment of the antenna

天线环境中地面反射的信号强度增加

✓ 正确答案

#E9A06🔗

What is the effective radiated power (ERP) of a repeater station with 200 watts transmitter power output, 4 dB feed line loss, 3.2 dB duplexer loss, 0.8 dB circulator loss, and 10 dBd antenna gain?

发射机功率输出为 200 瓦、馈线损耗为 4 dB、双工器损耗为 3.2 dB、环行器损耗为 0.8 dB、天线增益为 10 dBd 的中继站的有效辐射功率 (ERP) 是多少？

317 watts

317瓦

✓ 正确答案

2,000 watts

2,000瓦

126 watts

126瓦

300 watts

300瓦

#E9A07🔗

What is the effective isotropic radiated power (EIRP) of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

发射机功率输出为 200 瓦、馈线损耗为 2 dB、双工器损耗为 2.8 dB、环行器损耗为 1.2 dB、天线增益为 7 dBi 的中继站的有效全向辐射功率 (EIRP) 是多少？

159 watts

159瓦

252 watts

252瓦

✓ 正确答案

632 watts

632瓦

63.2 watts

63.2瓦

#E9A08🔗

Which frequency band has the smallest first Fresnel zone?

哪个频段的第一菲涅尔区最小？

5 . 8 GHz

5. 8GHz

✓ 正确答案

3.4 GHz

3.4GHz

2.4 GHz

2.4GHz

900 MHz

900兆赫

#E9A09🔗

What is antenna efficiency?

什么是天线效率？

Radiation resistance divided by transmission resistance

辐射电阻除以传输电阻

Radiation resistance divided by total resistance

辐射电阻除以总电阻

✓ 正确答案

Total resistance divided by radiation resistance

总电阻除以辐射电阻

Effective radiated power divided by transmitter output

有效辐射功率除以发射机输出

#E9A10🔗

Which of the following improves the efficiency of a ground-mounted quarter-wave vertical antenna?

以下哪一项可以提高地面安装四分之一波垂直天线的效率？

Installing a ground radial system

安装地面径向系统

✓ 正确答案

Isolating the coax shield from ground

将同轴电缆屏蔽层与地隔离

Shortening the radiating element

缩短辐射元件

All these choices are correct

所有这些选项都是正确的

#E9A11🔗

Which of the following determines ground losses for a ground-mounted vertical antenna operating on HF?

以下哪一项决定了在高频下运行的地面安装垂直天线的接地损耗？

The standing wave ratio

驻波比

Distance from the transmitter

距发射机的距离

Soil conductivity

土壤电导率

✓ 正确答案

Take-off angle

起飞角度

#E9A12🔗

How much gain does an antenna have compared to a half-wavelength dipole if it has 6 dB gain over an isotropic radiator?

如果天线比各向同性辐射器有 6 dB 增益，那么它与半波长偶极子相比有多少增益？

3 . 85 dB

3. 85分贝

✓ 正确答案

6.0 dB

6.0分贝

8.15 dB

8.15分贝

2.79 dB

2.79分贝

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FCC E9A - 天线与传输线系统

小节 E9A：天线与传输线系统