10

Electronics
Quarter 3 – Module 2:
Signal Transmission and
Reception of RADAR and LASER

DIVISION OF ANGELES CITY

Electronics – Grade 10
Alternative Delivery Mode
Quarter 3 – Module 2: Signal Transmission and Reception of Radar and Laser
First Edition, 2021

Republic Act 8293, section 176 states that: No copyright shall subsist in any work of
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Every effort has been exerted to locate and seek permission to use these materials from their
respective copyright owners. The publisher and authors do not represent nor claim ownership
over them.

Published by the Department of Education

Regional Director : May B. Eclar PhD, CESO V
OIC Asst. Regional Director : Rhoda T. Razon EdD, CESO V

Development Team of the Module

Writers: Arnel C. Perez, Ferdinand J. Soriano, Mark Albert T. Pineda

Editors: Marjorie D. Lacson, Nerissa N. Valdez, Eliza M. Roque
Reviewers: Gemima A. Estrabillo, Emily F. Sarmiento, Hermes P. Vargas,
Noel S. Reganit, Adrian P. Tamayo, Krislene Ida N. Mercado,
Jonathan Carrasco, Billy Ray B. Manuel, Marvin R. Leano,
Gemmarie G. Rivas
Illustrator: Lady Diane M. Bonifacio
Layout Artist: Lithos F. Sto. Domingo
Management Team: May B. Eclar PhD, CESO V
Rhoda T. Razon EdD, CESO V
Ma. Irelyn P. Tamayo PhD, CESE
Fernandina P. Otchengco PhD, CESE
Librada M. Rubio PhD
Ma. Editha R. Caparas EdD
Emily F. Sarmiento PhD
Gemima A. Estrabillo PhD
Rochella C. David

Printed in the Philippines by ________________________

Department of Education – Region III – Schools Division of Angeles City

Office Address: Jesus St., Pulungbulu, Angeles City

Telephone: (045) 322-5722; 322-4702; 888-0582; 887-6099
E-mail Address: angeles.city@deped.gov.ph
 10

Electronics
Quarter 3 – Module 2:
Signal Transmission and
Reception of RADAR and LASER
Introductory Message
This Self-Learning Module (SLM) is prepared so that you, our dear learners,
can continue your studies and learn while at home. Activities, questions, directions,
exercises, and discussions are carefully stated for you to understand each lesson.

Each SLM is composed of different parts. Each part shall guide you step-by-
step as you discover and understand the lesson prepared for you.

Pre-tests are provided to measure your prior knowledge on lessons in each

SLM. This will tell you if you need to proceed on completing this module or if you
need to ask your facilitator or your teacher’s assistance for better understanding of
the lesson. At the end of each module, you need to answer the post-test to self-check
your learning. Answer keys are provided for each activity and test. We trust that you
will be honest in using these.

In addition to the material in the main text, Notes to the Teacher are also
provided to our facilitators and parents for strategies and reminders on how they can
best help you on your home-based learning.

Please use this module with care. Do not put unnecessary marks on any part
of this SLM. Use a separate sheet of paper in answering the exercises and tests. And
read the instructions carefully before performing each task.

If you have any questions in using this SLM or any difficulty in answering the
tasks in this module, do not hesitate to consult your teacher or facilitator.

Thank you.
 What I Need to Know

This module was designed and written with you in mind. It is here to help you
master the principles of signal transmission and reception. The scope of this module
permits it to be used in many different learning situations. The language used
recognizes the diverse vocabulary level of students. The lessons are arranged to follow
the standard sequence of the course. But the order in which you read them can be
changed to correspond with the textbook you are now using.

The module will cover the lesson:

● Lesson 2 –Principles of signal transmission and reception

After going through this module, you are expected to:

● Describe the principles of signal transmission of radar and lasers

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 What I Know

Directions: Read each question carefully. Choose the letter of the correct answer.
1. What type of electromagnetic wave is usually used for transmission and
reception among televisions?
a. Infrared c. Radio wave
b. Microwave d. X-Ray
2. What device is used to receive data in the form of radio waves?
a. Antenna c. Transistor
b. Transmitter d. Tripod
3. What do you call the process of extracting information from a carrier wave?
a. Demodulation c. Modulation
b. Excretion d. Secretion
4. What does RADAR stand for?
a. Radio Detection and Reinforming
b. Radio Detection and Ranging
c. Radio Distortion and Ranging
d. Radio Distortion and Reinforming
5. What do you call the device that generates high power pulses?
a. Antenna c. Galvanometer
b. Capacitor d. Transmitter
6. Which among the following lasing medium is classified under the solid-
state?
a. Argon c. Ruby
b. Helium d. Smoke
7. Which electromagnetic spectrum does a laser belong to?
a. Radio waves c. Microwaves
b. Gamma waves d. Visible light
8. Which of the following animals can we compare with the principle of radar?
a. Chimpanzees c. Dolphins
b. Deer d. Spiders
9. What component in a receiver is commonly responsible for picking up laser
values?
a. Capacitor c. Integrated Circuit
b. Counter d. Phototransistor
10. How do radio waves generate in the transmitter?
a. Due to the unidirectional movement of current
b. Due to the uniform electric field of the charge
c. Due to the oscillating movement of charges
d. Due to the resistance of the conductor

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 Lesson Principles of Signal
2 Transmission and
Reception
A transmitter and receiver are employed to relay and intercept radio waves. A
radio wave serves as an information-bearing signal carrier; by occasionally
interrupting its transmission (as in dot-and-dash telegraphy), the information can be
encoded directly on the wave or impressed by it a method called modulation.

In its most common form, radio is used for the transmission of sounds (voice
and music) and pictures (television). The sounds and images are converted into
electrical signals by a microphone (sounds) or video camera (images), amplified and
used to modulate a carrier wave that has been generated by an oscillator circuit in a
transmitter. To evaluate this, it is crucial to verify that the system generates a power
level signal consistent with the maximum regulatory threshold. The modulated
carrier is also amplified and then added to an antenna that converts electrical sig
nals into space for electromagnetic radiation waves. At the speed of light, those waves
radiate and are transmitted not only by a line of sight but also by a deflection from
the ionosphere.

Due to the oscillating current where the electric field extends out into space,
radio waves are produced as the electric field changes rapidly. When you change an
electric field, it does not immediately change the distant pieces of it. The transition
is constrained by light velocity. Therefore, if the electric field is fluctuating, you
produce a wave.

However, how do radio waves and light relate to each other? How does this type
of waves generate pulses that are used to transmit and receive information from one
station to another?

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 What’s In

In our previous module, we learned that AM (or Amplitude Modulation) and FM

(or Frequency Modulation) are ways of broadcasting radio signals that transmit the
information in the form of electromagnetic waves. AM works by modulating (varying)
the amplitude of the signal or carrier transmitted according to the information being
sent, while the frequency remains constant. It differs from FM technology in which
information (sound) is encoded by varying the frequency of the wave, and the
amplitude is kept constant.

Different radio stations are found throughout Region 3 that use these radio
waves to broadcast news and information, play your favorite songs, and educate
learners.

In the activity below, complete the table by searching the AM/FM radio stations
that are found in each province.

Province AM Station FM Station

s1215 Radio Philippines
Aurora 92.1 DWBW RTV Baler
Network, Inc.
Bataan

Bulacan

Nueva Ecija

Pampanga

Tarlac

Zambales

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 What’s New

Electromagnetic waves usually are energy holders produced by the motion of

charged particles such as electrons. It is the only waveform that the oscillating
current generates is typically induced by the shifting electric field and magnetic field.
Radio waves are produced within these electromagnetic waves by this fluctuating
motion used to transfer information from one radio station to another.

To understand the concept of signal transmission and reception like radio

waves and other types of electromagnetic waves. Analyze the picture diagram and
encircle the letter in the boxes provided for each description.

Figure 3. Block diagram of a radar system

Description Answer
1. It collects signal
A. Loudspeaker B. Antenna
transmission.
2. The type of EM wave
A. Radio wave B. Gamma wave
being transmitted.
3. A transducer that is
used to relay a A. Microphone
B. Loudspeaker
message.
4. It extracts the
information received
A. Modulator B. Demodulator
from the
transmission.
5. A transducer that
translates the A. Microphone B. Loudspeaker
processed signal.

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 What is It

The transmission and interception of a transmitter and receiver’s radio waves

is used to generate and receive information-carrying signals. Radio wave functions
as an information-bearing signal carrier, and the information may be encoded
directly on the wave by interrupting its propagation regularly or impressed by a
technique called modulation. The actual information in a modulated signal is
contained in the sidebands or the frequencies. It is also added to the carrier wave
rather than in the carrier wave. When the radio waves reach the receiving antenna,
it induces a very small electromotive force (emf) fed to the radio receiver. Here, the
radio waves are first amplified, then the process of demodulation that extracts the
signal. The signal is amplified by audio amplifiers and then fed to the speaker for
reproduction into sound waves.

Principles of RADAR

RADAR (Radio Detection and Ranging) is a device that tracks and fixes the
location of targets at a distance using radio waves and operates on the theory of radio
echoes. These radio echoes are like the soundwaves used by bats and dolphins that
bounce back once the wave hits an object and reflects on the animals. This process
is called echolocation.
To detect the target, the radar transmitter’s job is to produce radio waves. It is
possible to classify the transmitters into oscillators and power amplifiers, while the
radar receiver’s role is to accept weak target signals and amplify them to a functional
level and convert the information stored in them from the radio frequency (RF) to the
baseband.

Figure 3. Block diagram of a radar system

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 The power amplifier’s output is delivered to the antenna by the duplexer that
will radiate it into space. The duplexer is a device that produces a short circuit at
the input to the receiver. This happens when the transmitter is operating so that
high power flows to the antenna and not the receiver. In nature, the receiver is
superheterodyne, which implies that it combines two high frequencies and generates
a low RF frequency then sent to the mixer and LO (local oscillator) that converts it
to an intermediate frequency then amplified by the IF amplifier. The IF amplifier
maximizes the output signal to peak ratio, then followed by the demodulator that
extracts the signal. The signal at the output of a detector or modulator is amplified
to provide sufficient gain to the signal.
Principles of LASER
A LASER (Light Amplification by Stimulated Emission of Radiation) is a device
that emits light through a process of optical amplification based on the stimulated
emission of electromagnetic radiation, which consists of three main components: a
lasing medium (solid, liquid, or gas), a stimulating energy source (pump) and an
optical resonator that is found in figure 4.
Lasing Medium is a substance used to produce the stimulated emission of
photons in a laser. It can be in gas, liquid, or semi-conducting material. Laser gain
media may vary from extended-length glass fibers to the submicron-length
semiconductor material. Stimulated emission (Pump), in laser action, is the release
of energy from an excited atom by artificial means. When more atoms occupy a higher
energy state than a lower one under normal temperature equilibrium, it is possible
to force atoms to return to an unexcited state by stimulating them with the same
energy as mirrors facing each other so that light emitted along the line between the
mirrors is reflected back and forth.

Figure 4. Laser Component

In figure 5, The process of transmission and reception of light where in the laser
transmitter contains a circuit for signal processing and a laser that is used to
produce the laser signal. To ensure consistent performance, laser diodes provide
photodiodes for feedback.

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 Figure 5. Laser Transmission Block Diagram

The receiver includes a signal processor and a detector (photodiode or

phototransistor) that can catch and read the incoming laser signal. Laser
communications are actually ousting radio waves as visible light wavelengths are
even more packed and tighter, which can relay more information with a stronger
signal per second. Instead of telephone wires, lasers are used in contact with optical
fibers.
Today, lasers have become one of the world’s most significant innovations used
in different industries ranging from information technology to telecommunications,
medicine, consumer electronics, law enforcement, military equipment,
entertainment, and manufacturing.

Terms and Concept Captured

1. Electromagnetic waves- are usually holders of energy formed by the
movement of charged particles such as electrons.

2. Amplitude- is the maximum displacement or distance moved by a point on a

vibrating body from its resting position.

3. Wavelength- is the distance between successive crests of a wave.

4. Wave Frequency- is the number of waves that pass a fixed point in each
amount of time. A higher-frequency wave has more energy than a lower-
frequency wave with the same amplitude.

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5. Radio waves- are a type of electromagnetic radiation with wavelengths in the
electromagnetic spectrum longer than infrared light. They range from the
length of a football to larger than our planet.

6. Transmission- is the process of sending and propagating an analog or digital

signal using wired, optical, or wireless electromagnetic medium.

7. Transmitter- a set of equipment used to generate and transmit

electromagnetic waves carrying messages or signals, especially those of radio
or television.

8. Modulation- is the process of changing the parameters of the carrier signal in

accordance with the instantaneous values of the modulating signal.

9. Demodulation- is extracting the original information-bearing signal from a

carrier wave.

10. Receiver- uses electronic filters to separate the desired radio frequency
signal from all the other signals picked up by the antenna, an electronic
amplifier to increase the power of the signal for further processing, and finally
recovers the desired information through demodulation.

11. RADAR- Radio Detection and Ranging) is a system that uses radio waves to
detect and to fix the position of targets at a distance that works on the principle
of radio echoes.

12. LASER- (Light Amplification by Stimulated Emission of Radiation) is a device

that emits light through a process of optical amplification based on
the stimulated emission of electromagnetic radiation.

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 What’s More

Activity 1. Different Somehow

Direction: List down the differences between a RADAR and LASER.

RADAR LASER

Assessment 1:
1. Which has more advantages between RADAR and LASER? Explain your
answer.
2. List down some uses of RADAR and LASER.

Activity 2. Its Laser time!

Direction: Label the components of the laser transmitter and describe the three main
component.

Components:
1. Lasing Medium-_______________________________________________________________

2. Optical resonator-_____________________________________________________________

3. Stimulating energy source-____________________________________________________

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Assessment 2:

1. What made the transmitter-receiver system of radar different from the laser?
2. Which of the two devices will provide the fastest means of sending the signals
or information? Support your answer.

Activity 3. Know your signal maker

Direction: Draw a simple block diagram of a RADAR and LASER transmission and
reception process on the boxes provided.

RADAR

LASER

Guide Questions:
Assessment 3:
1. What components are found in the RADAR and LASER block diagrams that are
similar to each other? Explain the similarities between the components.
2. Which of the two block diagrams will have a faster response to the signal
transmitted? Explain.

Rubric for assessment 3

1 point 2 points 3 points 4 points 5 points
Answer is Answer is Answer is Answer is Answer is
completely correct but correct and correct and correct and the
incorrect, and there is no there is some support needs support is fully
no support is support, OR support continuity developed
provided the answer is
incorrect but
there is some
correct
support

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 What I Have Learned

ACTIVITY 5. Fill in the gaps

Direction: Complete the sentences by putting the correct word/s from the box.

higher-frequency wave Signals signal processor

energy oscillators electronic filters
audio amplifiers optical amplification emf
extracting

1. A transmitter is a set of equipment used to generate and transmit

electromagnetic waves carrying messages or__________, especially those of
radio or television.
2. Electromagnetic waves are usually holders of __________formed by the
movement of charged particles such as electrons.
3. Demodulation is the process of _____________the original information bearing
signal from a carrier wave.
4. The receiver involves a ________________and detector that will capture and read
the incoming laser signal.
5. When the radio waves reach the receiving antenna, it induces _____ in it, which
is very small in magnitude and is fed to the radio receiver.
6. The transmitters can be classified into _________ and power amplifiers while
the function of the radar receiver is to accept weak target signals.
7. Receivers use _________________ to separate the desired radio frequency signal
from all the other signals picked up by the antenna.
8. A LASER is a device that emits light through a process
of _______________________ based on the stimulated emission of
electromagnetic radiation.
9. A ___________________has more energy than a lower-frequency wave with the
same amplitude.
10. The extracted signal that is amplified by _________________and then fed
to the speaker for reproduction into sound waves.

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 What I Can Do

Practical use of LASERS

The use of laser technologies for
diagnosing diseases is undoubtedly one
of the most significant applications of
lasers in general. Preserving and
improving health is an area where there
is always room for improvement.
Furthermore, lasers play a vital role in
it. For example, it can be used in cancer
diagnosis. Some new lasers can detect
changed cellular activity and, therefore,
diagnose cancer.
Another process that uses the benefits of lasers is box cutting. It enables high
precision in cutting for the best possible final product. Using laser technologies
makes the cardboard box cutting much easier. Laser box cutting is much faster and
more accurate compared to traditional methods, which allows it to preserve its
quality.
Optical communication has been one of the driving forces in developing laser
diode technology. Today, diode lasers are the key components of any broadband
communication systems. They are employed as a high-speed transmitter in digital
and analog fiber optic networks, pump lasers in Erbium doped amplifiers (EDFAs),
or as high-power pulsed lasers in the test and measurement field. Optical
communication is any form of telecommunication that uses light as the transmission
medium.
ACTIVITY 6. Can you do this?
Direction. Answer the question below.
1. How can laser help you in doing your daily activities?
2. How important is laser technology in the field of education?
Rubric for Activity 6

1 point 2 points 3 points 4 points 5 points

Answer is Answer is Answer is Answer is Answer is
completely correct but correct and correct and correct and the
incorrect, and there is no there is some support needs support is fully
no support is support, OR support continuity developed
provided the answer is
incorrect but
there is some
correct
support

13
 Assessment

Directions: Read each question carefully. Choose the letter of the correct answer.

1. What process is used to locate objects using radio waves or sound?

a. Echolocation c. Echo reproduction
b. Echo response d. Echo transmission

2. Which part of the Laser component captures the light that is translated by the
laser receiver?
a. Capacitor c. Phototransistor
b. Diode d. Transformer

3. What type of today’s technology is used in the field of telecommunications?

a. Laser c. Space Broadcast
b. Line-of-sight d. Twisted pair

4. Which component of a Laser Transmitter builds up the light energy in the beam?
a. Lasing medium c. Photodiode
b. Optical Resonator d. Pump

5. What causes the changing electric field and magnetic field in a charge?
a. Constant supply of voltage c. Stationary charge
b. Oscillating charges d. Unidirectional flow of current

6. Which type of wave is usually used by televisions to send information?

a. Infrared c. Radio wave
b. Microwave d. Sound wave

7. Which among the following situations is an application of RADAR?

a. Air and sea navigation of planes and ships
b. Circuit system used in a computer
c. Heating food using a microwave
d. All of the above

8. What is the term used to connect the antenna to the transmitter and receiver
during signal reception?
a. Duplexer c. Indicator
b. Echo signal d. Switch

9. Which among the following best describes the use of a laser?

a. Watching in an analog television c. Listening to music on the radio
b. Playing a remote-controlled car d. Storing files in a CD

10. Which laser component is responsible for providing energy to the system?
a. Lasing medium c. Photodiode
b. Optical Resonator d. Pump

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 Additional Activity

Direction: List down the similarities and differences of RADAR and LASER in the
Venn Diagram in terms of transmission and reception of signals.

RADAR LASER

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 16
What's New What I Know What’ s In
1. B 1. c 6. c
2. A 2. a 7. d Answer may vary
3. A 3. a 8. c
4. B 4. d 9. d
5. d 10. c
5. B
What’ s More
Activity 1
Assessment
1. Laser. It uses light which is much faster than radio waves.
2. Sea navigation, satellite detection, CD recording, spectroscopy, barcode
scanning, etc.
Answer Key
 17
What’ s More
Activity 2
1. Lasing Medium is a substance used to produce the stimulated emission of
photons in a laser.
2. Stimulated emission (Pump) releases energy from an excited atom by artificial
means
3. These are mirrors facing each other so that light emitted along the line
between the mirrors is reflected back and forth.
Guide Questions:
1. Radar system generally consists of a transmitter and receiver that produces
an electromagnetic signal which is radiated into space by an antenna while
Laser system transmitter and receiver produce the signals by way of a laser
beam.
2. Radar and Laser has the same speed in terms of data transfer since all type
electromagnetic waves has the same speed.
What’ s More
Activity 3
RADAR BLOCK DIAGRAM
 18
What’ s More
Activity 3 -Continuation
LASER BLOCK DIAGRAM
Guide Questions:
Answer may vary depending on how students understood the concepts of RADAR
and LASER and additional references used in the activity.
What I Have What I Can Do Assessment
Learned Answers may vary
1. a
1. Signals 2. c
2. Energy 3. a
3. Extracting 4. a
4. Signal processor
Additional 5. b
5. Emf Activity 6. c
6. Oscillators Answers may vary 7. a
7. Electronic filters 8. a
8. Optical amplification 9. d
9. Higher-Frequency wave 10. d
10. Audio amplifier
References
“Principles of signal transmission and reception”, Accessed December 16, 2020.
https://tinyurl.com/y6z5rs79

“Principles of radio transmission and reception”, Accessed December 16, 2020

https://tinyurl.com/y5ormnfg

“Radio Transmission”, Accessed December 16, 2020. https://tinyurl.com/yxzcpj7j

“Laser communication”, Accessed December 20, 2020

https://tinyurl.com/y6kw7w4v

“Radar Technology”, Accessed December 24, 2020 https://tinyurl.com/y4aa4kso

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For inquiries or feedback, please write or call:

Department of Education – Region III – Schools Division of Angeles City

Jesus St., Pulungbulu, Angeles City, Philippines, 2009

Telephone No.: (045) 322-5722; 322-4702; 888-0582; 887-6099

E-mail Address: angeles.city@deped.gov.ph