ĐIỆN tử VIỄN THÔNG DTVT2 nhom5 bai6 khotailieu

On striking, The radar signal is reflected3.. a The TV receives signals from the remote control b The TV follows your instructions On receiving signals from the remote control, the TV fo

UNIT 6: RADIO

Vocabulary

Appear ……….xuất hiện

Actual ………thực tế

Application ……….ứng dụng

Alphanumeric ………ký tự

Cost ………chi phí

Circuit ……… mạch điện

Classify ………phân loại

Digit ……… con số

Denote ……… ký hiệu

Electrolytic capacitor ….tụ hóa

Ease ……….làm giảm bớt

Electromagnetic wave … sóng điện từ

Enable ……… cho phép

Electrolytic ……… điện phân

Exist ……… tồn tại

Extreme ………cực

Employ ……….dùng

Fact ………thực tế, sự thật

Figure ………hình dung

Finally ………cuối, sau cùng

Grey ……… xám

General purpose ……….thường dùng Limited……… giới hạn Light emitting diode …… phát quang Letter ……… chữ cái

Range ……… dãy, loạt

Resistor ………điện trở

Impedance ……… trở kháng

Reflect ……… phản ánh Range ……… dãy, loạt

Reach ……… tới

Relaxing the tolerance du vi sai số

Preamp……… tiền khuếch đại Poor manufactory …… sản xuất tồi

Power amp ……… KĐ công suất Production ……… công việc sx Position ……… vị trí

Produce ……… sản xuất

Positive terminal ……… cực dương

Product ……… sản phẩm Prefer ……… thích hơn Power rectifier diode … diode chỉnh lưu Particular ……… riêng biệt Satisfactory ……… thỏa đáng

Semiconductor ………… chất bán dẫn

Seem ……… trong có vẻ

Tuning-in

Study this diagram Name five things, other than radio which make use of

electromagnetic waves

Rays ……… tia

Gamma rays ……… tia Gamma

Ultraviolet rays………… tia cực tím

Infra-red rays ……….tia hồng ngoại

Radio waves ……… sóng phát thanh

Wavelength ………bước sóng

Short wavelength……….bước sóng ngắn

Long wavelength ……….bước sóng dài

Low frequency ………… tần số thấp

High frequency ………….tần số cao

Visible light ……….ánh sáng nhìn thấy được

TASK2

Table 1 Surface wave

Frequencies (tần số) low frequency

Travels (đường truyền) along the ground

Range (khoảng cách) 1500km

Difficulties (khó khăn) absorption by the ground

TASK3

Frequencies (tần số) below 300MHz VHF, UHF

Travels (đường truyền)

Skywards and returned to earth by the ionosphere line of sight

transmission

Task 4 :

1

a transmitting aerial 2

e surface wave 3

d space wave 4

c sky wave 5

b receiving aerial TASK 5

1.

a The switch is closed

b Current flows through the primary of the transformer

When the switch is closed, current flows through the primary of the

Transformer

2.

a The radar signal strikes a plane

b The radar signal is reflected

On striking, The radar signal is reflected

3.

a A cell discharges quickly

b A cell may become hot

When discharging quickly, A cell may become hot

4.

a The TV receives signals from the remote control

b The TV follows your instructions

On receiving signals from the remote control, the TV follows your instructions 5.

a The radar receiver receives the reflected signal

b The signal is compared with the transmitted signal

On receiving the reflected signal, the signal is compared with the transmitted

signal

6.

a You choose a course in electronics

b You think carefully about your future

When choosing a course in electronics, you think carefully about your future 7.

a Microwave signals strike a high building

b Microwave signals are deflected

On striking a high building, microwave signals are deflected.

8.

a You make a recording

b You should ensure the recording levels are satisfactory

When making a recording, you should ensure the recording levels are

satisfactory

9.

a The alarm detects an intruder

b The alarm triggers an audible warning

On detecting an intruder, the alarm triggers an audible warning.

10.

a The remote control button is pressed

b The television set changes channel

On pressing remote control button, the television set changes channel Task 7 :

Verb Noun (component) Noun (property)

Absorb Absorber Absorption

Attenuate Attenuator Attenuation

Communicate Communicator Communication

Conduct Conductor Conductivity

Induct Inductor Induction

Modulate Modulator Modulation

Reflect Reflector Reflection

Resist Resistor Resistance

1 : AF audio frequency

2 : RF Radio frequency

3 : AM Amplitude modulated

4: FM Frequency modulated

Task 10: Identify the wave Use these terms

a : RF carier

b: AF signal

c: AM carrier

d: FM carrier

- Frequency modulated

- High frequency ( 76 MHz – 130 Mhz)

- Signals near

- Amplitude modulated

- Low frequency ( 30KHz – 16MHz)

- Signals travel farther

Task 11:

Aerial Receiver weak RF signals

RF tuner Modulater Rf carrier

RF amplifier Amplifier RF wave

Detector Detect RF signal

AF amplifier Amplifier AF signal

Loudspeaker Convert the audio signal into sound

TASK 12

Radio waves are very popular in today's life It was used extensively in the field of communication today Here are all described block diagram of a simple radio receiver Diagram includes seven components Aerial is receiving antenna, receiver RF carrier is modulated and put into an amplifier Audio signal is separated from the carrier and into the audio signal amplifier and power amplifier signal audio signal after amplification was converted and emitted speakers