Circuit2 Report
Name: Mohamed Ahmed Hassan Ibrahim
Sec: 8
Num.: 22210194
Academic level: 2nd E. Power
DR: Abdul Latif
Research topic: Mutual Coupling effects & Two port network app.
Mutual Coupling
Because of time-varying currents in surrounding circuits, the
magnetic flux through the area contained by a circuit often
varies with time circuits.
Mutual coupling in an array cause:
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Changes in the radiation pattern of the array.
Changes in the input impedance of the individual antenna
elements in an array.
A magnetic field surrounds the "disturbing cable" and the
"victim cable." Figure 1 shows the situation. The level of
disturbance is determined by current variation (di/dt) and mutual
inductance coupling.
Fig.1
The inductive coupling increases with:
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Frequency: the inductive reactance is directly proportional to
the frequency (XL = 2πFL)
The distance between disturbing and victim cables and the
cable length which are parallel
The cable height in relation to the reference plane (above
ground)
The load impedance of the cable or the disturbing circuit
Advantages of Mutual Coupling:
-Due to the presence of coupling, the phased array's
performance degrades; however, this cannot be generalised. In
some circumstances, the presence of coupling is said to be
favourable. Multiple element antenna (MEA) effective in
managing from coupling because it increases channel capacity.
Mutual Coupling Effect:
on equipment:
- Because of their close proximity, two wires in the same cable
or raceway can couple electromagnetically at high frequencies.
The main issue is mutual inductance, although electrostatic
interference from outside sources can also be a concern. These
issues are considerably reduced by encasing the cable in
grounded metallic conduit or metallic shielding.
- At very high frequencies, electromagnetic coupling becomes a
fact of life in point-to-point chassis wiring, printed circuit board
traces and even within microchips. Good design can prevent
losses from parasitic capacitive and inductive reactance.
Conductors including traces should be short and straight.
- electromagnetic bomb:
A weapon intended to disable electronic devices through a major
electromagnetic pulse (electromagnetic pulse) that can interfere with
electrical/electronic devices and their operating systems to cause damage
and damage to them. Their effects are usually not more than 10 km from
the explosion if they are not associated with a nuclear bomb or are
specially designed to produce the massive electromagnetic pulse. If small
nuclear weapons detonate at high altitude, they can cause an
electromagnetic pulse strong enough to disable or damage electronic
.equipment many miles from the blast site
The effect of electromagnetic fields on humans:
- Effect on the immune system: There are a number of studies
conducted to investigate the effect of electromagnetic fields on
the immune system, and the result was that no effect on the
function of the immune system was observed.
- Effect on the brain: As electromagnetic fields may affect
brain function, for example, the use of a cell phone, although it
has a low electromagnetic field, it affects brain cells, and there
are changes in glucose in the brain after using a cell phone, and
one showed Studies show that brain glucose increases when the
.cell phone is turned on, which can lead to encephalitis
- Effect on antioxidants: Exposure to electromagnetic fields,
such as those generated by cellular devices, leads to the loss of
antioxidants present in saliva, and the importance of saliva is
that it is one of the first lines of defines against microbial
infections
- Cancer: There are many reports that exposure to sources of
electromagnetic fields, including cellular devices, Wi-Fi
devices, and microwaves, can cause cancer, and for children,
electromagnetic fields expose them to the risk of developing
cancer, and some studies have indicated that cell phone
radiation, increases the risk of malignant tumours in the brain,
malignant tumours in the ear, and acoustic neuromas have also
been linked to using the phone.
Prevention of electromagnetic fields:
-Keep the cell phone and the computer as far as possible:
Cell phone should be avoided in clothes pockets, and the laptop
should not be placed on the lap or on the feet when using it, and
the hands and legs should be kept away from the power source,
which is the battery
-Avoid using Bluetooth headphones: they can be replaced with
a loudspeaker, so the device remains somewhat away from the
user, as the radiation is greatly reduced, with every inch, away
from the body
-Eat useful foods: Some foods have the ability to protect the
nucleic acids in the body from damage, such as grapes, peaches,
walnuts, dates, broccoli, and coriander
----------------------------------------------------------------------------Two port network application:
There are many applications on Two port network including the
most famous and frequently used in our practical and daily life,
which is transformers
Definition of a transformer: It is a device consisting of two
coils of separate wires wrapped around iron bars only a small
distance, the end connected to the generator is called the
primary winding while the end connected to the load is called
the secondary winding.
Its uses:
1- Transferring electrical power over long distances from the
place of its generation to the places of its consumption.
2- It is used with measuring and protection devices when
electrical currents and efforts are high by reducing the values of
currents or efforts to small values that can be measured and
dealt with.
3- It is used in electrical insulation to prevent electromagnetic
interference in electronic circuits.
Working principle:
The principle of operation of the transformer is based on
Faraday's law of electromagnetic induction, which states that
(the value of the impulsive force (electrical potential) is directly
proportional to the rate of magnetic flow change.
Transformer working theory
When the current passes in the first coil, a variable magnetic field is
created, depending on the change in the current flowing through this
coil.
(Imaginary lines) cut the second file, and since the resultant field
thereof is a variable field, this change is in
The magnetic penetration of the coils works to move the electrons
with the second coil and this movement
It is called the magneto motive force mmf that causes
The flow of current in the second coil, and that current is called the
inferred current by self-induction
The first file and the second file:
Fig.2 …Transformer Diagram
Types of Electrical transformer
1) Step up transformer
They are transformers that are used to convert voltage or current
from low to higher voltage
Fig.3.. Step up transformer
2) Step-down transformer
It reduces the very high current, which ranges
Between 16 kV to 60 kV it is installed
At the end of the distribution networks, reducing the voltage to 220
EV to feed factories and homes
Fig.3… Step-down transformer
Summary:
The effect of electromagnetic fields on humans:
1-- Effect on the immune system:
2--Effect on the brain
3-- Effect on antioxidants
Two port network application:
-transformers
Types of Electrical transformer:
1) Step up transformer
2) Step-down transformer
Reference
1) Knowlton, A.E., ed. (1949). Standard Handbook for Electrical Engineers (8th ed.).
McGraw-Hill. p. see esp. Section 6 Transformers
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2) Internet research (All the illustrations, brands and products used
hereby belong to their respective proprietors, as well as any other types
of intellectual property.)