找回密码
 注册
搜索
楼主: linux0702

[讨论] RF测试人员能力测试,可用于面试大公司

  [复制链接]
发表于 2016-3-3 00:10:04 来自手机 | 显示全部楼层
看看怎么样
点评回复

使用道具 举报

发表于 2016-3-7 20:37:44 | 显示全部楼层
毫无意义的帖子
点评回复

使用道具 举报

发表于 2016-3-13 17:11:04 | 显示全部楼层
到底怎么样啊
点评回复

使用道具 举报

发表于 2016-3-14 09:08:50 | 显示全部楼层

深圳市华海智能卡有限公司,专业生产手机耦合测试白卡,2G ,3G,4G,NFC,全网通测试白卡。欢迎来电咨询!

    联系人:王杰
    电话:0755-27767766-8003
    手机:18098945001
    企业Q Q:2850627135
    总机:0755-27767766,27767866
    传真:0755-27767766-8010
    企业邮箱:huahai05@cnhuahai.com
    工厂地址:广东省深圳市宝安区石岩镇松白路宝路工业区1栋6楼(石岩汽车站对面)
    欢 迎 来 电 来 函 来 考 察!
点评回复

使用道具 举报

发表于 2016-4-25 12:02:57 | 显示全部楼层
直接贴文章不是很好,没钱买,也没有讨论的想法了
点评回复

使用道具 举报

发表于 2016-4-25 12:03:18 | 显示全部楼层
在这个处处都要银币的时代,不得不弄个牛B的数字来显眼,于是我抄下了这段话,专门用来回帖,好让我每天有固定的积分收入来
点评回复

使用道具 举报

发表于 2016-5-12 11:07:57 | 显示全部楼层
好东西
点评回复

使用道具 举报

发表于 2016-5-27 09:31:50 | 显示全部楼层
浪费我的钱
点评回复

使用道具 举报

发表于 2016-5-28 15:10:23 | 显示全部楼层
什么东西啊 值不值的啊。
点评回复

使用道具 举报

发表于 2016-5-29 20:51:19 | 显示全部楼层
附件内容如下:
[em02]RF Quiz #1

1. What is the impedance of free space?



2. What happens to the noise figure of a receiver when a 10 dB attenuator is added at the input?

a) Noise figure increases by 10 dB
b) Noise figure decreases by 10 dB
c) Noise figure doesn't change

3. An RF system has a linear throughput gain of +10 dB and an output 3rd-order intercept point (OIP3) of +30 dBm. What is the input 3rd-order intercept point (IIP3)?

a) +20 dBm
b) +40 dBm
c) +30 dBm

4. Which filter type has the greatest selectivity for a given order (i.e., N=5)?

a) Bessel
b) Chebychev (ripple=0.1 dB)
c) Butterworth

5. Which mixer spurious product is a 5th-order product?

a) 1*LO + 5*RF
b) 6*LO - 1*RF
c) 3*LO - 2*IF

6. A 2.8 GHz oscillator is phase-locked to a 10 MHz reference oscillator that has a single-sided phase noise of -100 dBc at 1 kHz offset. What is the single-sided phase noise of the 2.8 GHz oscillator at 1 kHz offset?

a) -48.6 dBc
b) -100 dBc
c) -51.1 dBc

7. What is the power of a 2 Vpk-pk sine wave across a 50 ohm load?

a) -20.0 dBm
b) +10.0 dBm
c) +19.0 dBm

8. Which 2-port S-parameter is commonly referred to as "reverse isolation" in an amplifier?

a) S21
b) S22
c) S12

9. What are the minimum and maximum combined VSWR limits at an interface characterized by a 1.25:1 VSWR and a 2.00:1 VSWR?

a) 1.75:1 (min), 2.25:1 (max)
b) 1.60:1 (min), 2.50:1 (max)
c) 0.75:1 (min), 3.25:1 (max)

10. An ideal directional coupler has a directivity of 25 dB and an isolation of 40 dB. What is its coupling value?

a) 65 dB
b) 40 dB
c) 15 dB











RF Quiz #2

1. On a Smith chart, what does a point in the bottom half of the chart represent?

a) An inductive impedance
b) A capacitive impedance
c) Power saturation

2. While we're on the subject of Smith charts, what is the impedance of the point at the far left edge of the center horizontal line?

a) Infinite ohms (open circuit)
b) Zero ohms (short circuit)
c) 50 ohm match

3. A single-conversion downconverter uses a high-side local oscillator (LO) to translate the input radio frequency (RF) to an intermediate frequency (IF). Will spectral inversion occur at IF?

a) Yes, always
b) No, never
c) Sometimes

4. What happens to the noise floor of a spectrum analyzer when the input filter resolution bandwidth is decreased by two decades?

a) 20 dB increase
b) 20 dB decrease
c) 40 dB decrease

5. What is a primary advantage of a quadrature modulator?

a) Low LO power required
b) Four separate outputs
c) Single-sideband output

6. What is meant by dBi as applied to antennas?

a) Isolation in decibels
b) Physical size relative to intrinsic antennas
c) Gain relative to an isotropic radiator

7. What is the power dynamic range of an ideal 12-bit analog-to-digital converter (ADC)?

a) 36.12 dB
b) 120 dB
c) 72.25 dB

8. An ideal 10 dB attenuator is added in front of a load that has a 2.00:1 VSWR. What is the resulting VSWR of the load + attenuator?

a) 1.07:1
b) 2.10:1
c) 12.0:1

9. What is the thermal noise power in a 1 MHz bandwidth when the system temperature is 15 degrees Celsius (assume gain and noise figure are 0 dB)?

a) -114.0 dBm (in a 1 MHz bandwidth)
b) -114.0 dBm
c) -114.0 dBm/Hz

10. Two equal amplitude tones have a power of +10 dBm, and generate a pair of equal amplitude 3rd-order intermodulation products at -20 dBm. What is the 2-tone, 3rd-order intercept point (IP3) of the system?

a) +40 dBm
b) +25 dBm
c) +20 dBm





RF  Quiz #3

1. What is a primary advantage to using 90 degree (quadrature) hybrid couplers in amplifier designs?

a) Wider bandwidth possible
b) Low noise figure
c) Input/output impedance not dependent on devices as long as device impedances are equal

2. Why is there a frequency term in the equation for free-space path loss?

a) There is no frequency term
b) Atmospheric absorption
c) Antenna geometry requires it

3. If an amplifier has a noise temperature of 60K, what is its noise figure for an ambient temperature of 290K?

a) 8.0 dB
b) 80 dB
c) 0.82 dB

4. What is a primary advantage of offset-quadrature-phase-shift-keying (OQPSK) over standard QPSK?

a) Greater data rates possible
b) Greater spectral efficiency
c) More constant envelope power

5. A mixer has the following input frequencies:  RF = 800 MHz, LO = 870 MHz. The desired output frequency is 70 MHz. What is the image frequency?

a) 940 MHz
b) 1670 MHz
c) 140 MHz

6. What is the spurious-free dynamic range of a system with IP3 = +30 dBm and a minimum discernible signal (MDS) level of -90 dBm?

a) 80 dB
b) 120 dB
c) 60 dB

7. A spectrum analyzer displays a component at 10 MHz @ 0 dBm, 30 MHz @ -10 dBm, 50 MHz @ -14 dBm, 70 MHz @ -17 dBm, and all of the other odd harmonics until they disappear into the noise. What was the most likely input signal that caused the spectrum?

a) A 10 MHz square wave (0 Vdc)
b) A 10 MHz triangle wave (0 Vdc)
c) A 10 MHz cosine wave (0 Vdc)

8. On which side of a rectangular waveguide is an E-bend made?

a) The long dimension
b) The short dimension
c) The inside

9. During a network analyzer calibration, why are both a short circuit and an open circuit used?

a) They average to 50 ohms in an RF system
b) To determine the characteristic impedance of the measurement system
c) Both are easy to produce to at high accuracy

10. What is the first harmonic of 1 GHz?

a) 1 GHz
b) 2 GHz
c) 10 GHz





RF  Quiz #4

1. Which of the following can cause frequency intermodulation products in a system?

a) Only semiconductor junctions like diodes and transistors (amplifiers)
b) Cable connectors, bolted or riveted antenna panels, isolators and circulators
c) Both a) and b)

2. What is the melting temperature of standard 60/40, tin/lead solder?

a) 100°C (212°F)
b) 250°C (482°F)
c) 186°C (386°F)

3. What is the frequency band for the 900 MHz GSM cellular band?

a) Tx: 880-915 MHz / Rx: 925-960 MHz
b) Tx: 824-849 MHz / Rx: 869-894 MHz
c) There is no 900 MHz GSM band

4. What does GSM stand for?

a) General System for Mobile phones
b) Greater Spectrum for Mobile phones
c) Global System for Mobile Communication

5. What does POTS stand for (in communications)?

a) Plain Old Telephone System
b) PersOnal Telephony System
c) Personal Orbital & Terrestrial  Satellite

6. Which of these pairs of materials in the triboelectric series have the greatest charge transfer potential?

a) Silk & Wool
b) Rubber Balloon & Celluloid
c) Glass & Hard Rubber

7. Along which side of rectangular waveguide is an "E" bend made?

a) Longer side
b) Shorter side
c) "E"ither side

8. What is the lowest modulation index at which an FM carrier is suppressed?

a) 2.40
b) p (3.1416)
c) Only AM carriers can be suppressed

9. How much current is required through the human body to cause an onset to muscular paralysis during electrocution?

a) Voltage is the culprit during electrocution, not current
b) 21 mA
c) ? amp

10. At what frequency is electromagnetic energy maximally absorbed due to oxygen in the atmosphere?

a) 22 GHz
b) Only water in the atmosphere absorbs electromagnetic energy
c) 63 GHz


点评回复

使用道具 举报

发表于 2016-5-30 08:27:37 | 显示全部楼层
學習學習
点评回复

使用道具 举报

发表于 2016-5-30 16:32:41 | 显示全部楼层
在这个处处都要银币的时代,不得不弄个牛B的数字来显眼,于是我抄下了这段话,专门用来回帖,好让我每天有固定的积分收入来为学习存子弹
点评回复

使用道具 举报

发表于 2016-5-31 16:28:30 | 显示全部楼层
什么东西里面,好像去看看
点评回复

使用道具 举报

发表于 2016-6-22 16:46:55 | 显示全部楼层
看到大家都骂你,我就就放心了
点评回复

使用道具 举报

发表于 2016-7-26 13:20:04 | 显示全部楼层
太啃爹了
点评回复

使用道具 举报

发表于 2016-7-27 21:06:29 | 显示全部楼层
[em05]我是新人,下载学习学习。
点评回复

使用道具 举报

发表于 2016-8-4 15:38:13 | 显示全部楼层
你的东东 老贵
点评回复

使用道具 举报

发表于 2016-8-4 15:40:16 | 显示全部楼层
有一种强烈被坑的感觉
点评回复

使用道具 举报

发表于 2017-10-28 11:46:07 | 显示全部楼层
有人突然你让他
点评回复

使用道具 举报

发表于 2017-11-10 10:49:18 | 显示全部楼层
bnv cvnbnbnb
点评回复

使用道具 举报

高级模式
B Color Image Link Quote Code Smilies

本版积分规则

Archiver|手机版|小黑屋|52RD我爱研发网 ( 沪ICP备2022007804号-2 )

GMT+8, 2024-3-19 16:22 , Processed in 0.049595 second(s), 15 queries , Gzip On.

Powered by Discuz! X3.5

© 2001-2023 Discuz! Team.

快速回复 返回顶部 返回列表