Microstrip
An electronic device used for high-frequency signal
transmission
Introduction :
Transmission Lines:
Transmission line
They are used to transmit electrical energy,or signals,
from one location to another: to connect a source to a
load, such as a transmitter to an antenna.
The transmission lines employed can be broadly
classified into three types one of them is: Multi conductor lines
Multi conductor lines:
The transmission lines which has more than one
conductor are called as multi-conductor lines: Microstrip line
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Co-axial lines
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Strip lines
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Micro strip lines
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Slot lines
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Coplanar lines,etc.
W hat is Micros trip line :
A microstrip line is a type of electrical transmission line
that's widely used in high-frequency electronic circuits,
particularly in microwave and radio-frequency (RF)
applications.
Structure :
* Conductor: A narrow metallic strip (the
Properties : "microstrip") is placed on top of a dielectric
substrate.
*Thickness is in Micrometer.
* Ground Plane: A conductive layer (the "ground
* Height is in millimeter.
* Have Width-to-height ratio(u=w/h) plane") is located on the opposite side of the
0.1<u<10 dielectric substrate.
* Propagation in Z-direction. * Dielectric Substrate: The insulating material
between the conductor and the ground plane.
Electromagnetic Fields :
➔
The electromagnetic wave travels partly in the
dielectric substrate and partly in the air above it,
resulting in a quasi-TEM (transverse
electromagnetic) mode of propagation.
➔
The microstrip can be thought of as being a line composed of a homogeneous dielectric
whose overall dielectric constant is greater than air but smaller than that of the substrate.
➔
Fringing Effect can not ignored because The electromagnetic waves are not purely TEM in
nature but Quais-TEM.
➔
A Fringing effect means phenomenon where the electromagnetic fields extend beyond the
physical edges of the conductive strip.
Effe ctive Die le ctric Cons tant:
The propagation field line in microstrip lie partially in air and in dielectric substrate. The
propagation delay tie is decided by an effective dielectric constant. The quasi TEM
mode is controlled by
Characte ris tic Im pe dance :
The characteristic impedance of a microstrip line is determined by the dimensions of
the conductor,the thickness of the dielectric substrate,and the dielectric constant of the
substrate material. This allows designers to control the impedence for optimal signal
transmission
Wave le ngth & Ve locity :
The guide wavelength for propagating quasi TEM mode is given as
Im ple m e ntations :
* Mobile Phones & Satellite Communications: Microstrip antennas are integral to
cellular devices, enabling compact and efficient wireless communication.
* Wi-Fi and Bluetooth: Routers, access points, and Bluetooth-enabled devices rely on
microstrip components for signal transmission and reception.
* Radar Systems: Microstrip technology is used in radar systems for signal generation,
processing, and antenna design.
* High-Speed Digital Circuits: While not strictly RF, microstrip principles are applied in
high-speed digital PCB design to control signal integrity and minimize signal distortion
* GPS Devices: GPS devices in our cars and smartphones use microstrip antennas to
receive signals from satellites, enabling accurate location tracking.
* Automotive Safety: Modern vehicles equipped with advanced driver-assistance
systems (ADAS) use radar sensors that rely on microstrip technology for collision
avoidance and adaptive cruise control.
Advantage s :
* Relatively inexpensive to manufacture.
* Transmission of High-Frequency Signals: Microstrip lines are designed to efficiently
transmit high-frequency signals, making them essential in devices like:
* Cell phones
* Satellite communication systems
* Radar systems
* Wi-Fi devices
* Printed Circuit Boards (PCBs): They are easily fabricated on PCBs, which simplifies
the manufacturing process
* Planar Structure: Their planar design allows for the integration of other circuit
components on the same substrate
Dis advantage s :
* Can be susceptible to radiation losses at very high frequencies.
* The electromagnetic fields are not entirely contained within the substrate, which can
lead to interference with other components.
In Es s e nce :
Any application that involves the generation, transmission, or reception of high-
frequency signals is a potential candidate for microstrip technology. Its versatility, ease
of fabrication, and cost-effectiveness make it a cornerstone of modern electronic
design.
