ĐIỆN tử VIỄN THÔNG D8DTVT2 nhom8 bai6 khotailieu

Họ và tên : Vũ Anh Cường
Lê Văn Hải
Phạm Hồng Phái
Nguyễn Văn Đại
Đỗ Mạnh Cường
Trần Văn Tuất

Lacture 6 : RADiO

1: Vocabulary
Wavelength: bước sóng
Frequency: tần số
Ultraviolet: tia cực tím
Visible: nhìn thấy
Transmitting: truyền
Surface: bề mặt
Along: tiến về phí trước
Curvature: uốn cong
Range: phạm vi
Mainly : chính
Extant: quy mô
Conductor: chất dẫn


Sand: cát
Absorb: hấp thụ
Certain: chắc chắn, cố định
Typically: tiêu biểu
Ionosphere: tầng điện ly
Molecules: phân tử
Above: phía trên

Bounces: nảy lên
Gradually: dần dần
Refracted: khúc xạ
Reflection: phản chiếu
Space wave: sóng trung
Transmission: truyền
Effective: hiệu quả
Obstacles: cản trở
Satellite: vệ tinh
Communication: thông tin lien lạc
Carry: mang
Pass: chuyền.

Task 2:

Table 1:

Surface


Frequencies

Low frequency

Travels

This travel along the ground.

Range

1500km

Difficulties

Absorption by the ground.

Task 3:

Table 2:

Sky wave

Frequencies

30MHz

Space wave
VHF, UHF, and microwave signals.

Travels

Skyward and returned to earth by
the ionosphere.

Giving line of sigh transmission.

Range

Hàng nghìn Km

150km

Difficulties

Attenuated by reflection

Hills, building, or trees.

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: When the switch is closed, current flows through the primary of the transformer.
2: On striking, the radar signal is reflected.
3: When dischargi quickly, a cell may become hot.
4: On receiving from the remote control,the TV follows your instructions.
5: On receiving the reflected signal, the signal is compared with the transmitted signal.
6: When choosing a course in electronics, you think carefully about your future.
7: On striking a high building, microwave signals are deflected.
8: When making a recording, you should ensure the recording levels are satisfactory.
9: On detecing an intrucder, the alarm triggers an audible warning.
10: On pressing remote control button, the television set changes channel.

Task 7:

Verb
Absorb
Attenuate
Communicate
Conduct
Induct
Modulate
Reflect
Resist

Noun (component)

Noun (property)

Absorber
Attenuator

Communicator
Conductor
Inductor
Modulator
Reflector
Resistor

Absorption
Attenuation
Communication
Conductivity
Induction
Modulation
Reflection
Resistance


Task 9:
1)

AF

: audio frequency : tần số âm thanh = âm tầng

2)

RF

: radio frequency : tần số vô tuyến = cao tầng

3)

AM

: amplitude-modulated : điều biên

4)

FM

: frequency-modulated : điều tần

Task 10:

1.FM carrier

2. AM carrier

3.AF signal

4.RF carrier


Task 11:
Component

Function
Receives weak RF signal

1.Aerial

2.RF tuner

Selects the required RF wave.
Amplified and passed to the detector

3.RF amplifier
4.Detector
5.AF amlifier
6.loudspeaker

separates the audio modulation from the RF
carrier wave
The audio frequency amplifier then amplifies the
audio signal to make it strong enough to drive the
loudspeaker.
Converts the audio signal into sound