Introduction To Mobile Phone Parts.docx

7/27/2019 Introduction To Mobile Phone Parts.docx

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Introduction To Mobile Phone Parts.

Dear

friends here we will discuss about what kind of functions a typicalmobile phone has so let us start our new lesson. while starting i would

like to say all of you that you please keep in touch with me by our

contact us page and please don't feel any hesitation to ask me anyquestion if you have about these lessons. these lessons will make youlearn good repairing skills so keep reading these lectures.

First of all we will discuss how many main functions a mobile phone often has irrespectively of

mobile brands.There are three major sections inside a mobile phone

Power Section

Radio Section Computer Section

Power Section:

Apower section deals with power related tasks such as power distribution

or charging the battery so this section can be divided into two sub

sections like.

Power DistributionA power distribution section

is built around an "power IC" it takes 3.6V power from battery and

regulates its power and then distributes to the other components usedin mobile phone circuit. in some mobile phones tech "RF Power

amplifier" uses more Power than provided bye mobile phone's battery

.i.e. 4.7 V or 5.6 V in some phones. the power Ic with a power boaster

coil is used to increase voltages. so we can say that power IC is usedto provide power to other components how much they needed. either less

than battery voltage or more than it.

Charging SectionA charging

section works for battery charging purposes.it is often consists a

fuse, a coil, a protecting diode, a filter capacitor and charging ICand some other discreet. the charging section helps battery to be

charged when it needs and when battery is charged, charging IC reads

its state of charge and feels it full charged and then disconnects

charging from it.Radio Section:

A radio section has basically a set of four main functions.wich are.

Band Switching

RF Power Amplification Transmitter

Receiver

Band Switching:In the modern mobile phone communication techniques. the frequency of mobile phone


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communication is divided into three bands

GSM (operates on 900 MHz)

DCS (operates on 1800 MHz) PCS (operates on 1900 MHz)

the

third band is used only in USA whereas the first two bands are used inthe rest of the world. band switching is done bye a "ceramic antennaswitch" it reads from the radiation dispersed in the air and then

switches to the appropriate band.

in the very first phase of mobilephones there were single band handsets which operated on single

frequency band but now a days all the handsets are dual band or tri

band in operation.

RF Power AmplifierRF power amplifier is

often called as ".PA" or"Transmitter" its functions is to amplify or

boast the power which is being transmitted to air, so may it would beable to communicate with long distances. a typical .PA can amplify rf

power up to 0.6W or 600mW. This amount of rf power is sufficient to

communicate nearly 20 to 25 kilometers in open area, but all the PA's

are controlled by there rf signal processor, so if we are near our cellbase tower the PA of our phone will transmit low power but if we are

far away it will produce its maximum power.

TransmittingA mobile

phone's rf section is basically built around an rf IC which is often

called rf signal processor whereas in nokia it is called hagar IC in

some hand sets and in some hand sets it is called Mjoelner.irrespectively of the brands and verity of names we call it rf signal

processor. this IC works as transmitter and receiver as well. working

as transmitter it takes instructions from phone's computer and alsotakes audio data from audio section and creates radio waves then mixes

audio data to its radio waves according to the instructions given by

computer section. this mixer of audio and radio is sent to PA toamplify its strength

Reciever

A reciver section for rf waves is

built in rf IC, as it is said that this IC works for dual purposesfirst transmitting and section recieving. in the recieving section of

mobile phones a radio signal is gather from ceramic antenna switch and

then it is filtered and sent to rf IC to further process. in rf IC

signal is detected and then rectified for audio and data which is sentto audio IC or computer section.

Computer Section:

A computer section in mobile phone consists of two main functions CPU(central processing unit)


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Memory (RAM, FLASH, COMBO CHIP)

CPU:

ACPU is used in mobile phones as a central processing arithematic or

controler. the cpu controls various functions in mobile phones like

signal, display, sound converting(DSP), charging, power on, rf channelcontroler, rf tx power conroller, LEDs, vibrator, data processing, datastoring etc. so we can say that if a cpu is damaged in any mobile phone

it cannot be repaired unless the CPU is not replaced but this type of

fault is not even seen to me ever either memory chips can be damaged.in brand Nokia CPU is named with two different words (MAD or UPP)

Memory:

there are two main types of memories used in mobile phones

RAM (Random Access Memory)The

RAM is used in mobile phones to store user data in mobile phones. So

these a days we can store pictures, messages, ringtones, applications,themes and other these type of things in mobile phones so CPU stores

these types of data in the RAM of our mobile phones.

Flash (eeprom, ROM etc)

Theflash chip is used in mobile phones to hold mobile phone's operating

system in it. so if the flash chip is damaged in mobile phones the

phone cannot power on properly because all the instructions to start amobile phones and its various tasks like call making , display etc are

stored in the flash chip of mobile phones.

Combo Chip

In smoemobile phones there is a combined type of memory used which is called

combo memory chips these types of memories work for both like RAM and

Flash.The clear example of this type of memory is used in Nokia 1100.Note: Multy Media Cards are not a part of mobile phones becaues they are used externally.

Mobile Phone Function

Dear

friends here we will discuss about what kind of functions a typicalmobile phone has so let us start our new lesson. while starting i would

like to say all of you that you please keep in touch with me by our

contact us page and please don't feel any hesitation to ask me any

question if you have about these lessons. these lessons will make youlearn good repairing skills so keep reading these lectures.

First of all we will discuss how many main functions a mobile phone often has irrespectively ofmobile brands.


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There are three major sections inside a mobile phone

Power Section

Radio Section

Computer SectionPower Section:A

power section deals with power related tasks such as power distribution

or charging the battery so this section can be divided into two subsections like.

Power Distribution

A power distribution section

is built around an "power IC" it takes 3.6V power from battery andregulates its power and then distributes to the other components used

in mobile phone circuit. in some mobile phones tech "RF Power

amplifier" uses more Power than provided bye mobile phone's battery.i.e. 4.7 V or 5.6 V in some phones. the power Ic with a power boaster

coil is used to increase voltages. so we can say that power IC is used

to provide power to other components how much they needed. either less

than battery voltage or more than it.Charging Section

A charging

section works for battery charging purposes.it is often consists afuse, a coil, a protecting diode, a filter capacitor and charging IC

and some other discreet. the charging section helps battery to be

charged when it needs and when battery is charged, charging IC reads

its state of charge and feels it full charged and then disconnectscharging from it.

Radio Section:A radio section has basically a set of four main functions.wich are.

Band Switching

RF Power Amplification Transmitter

Receiver

Band Switching:

In the modern mobile phone communication techniques. the frequency of mobile phonecommunication is divided into three bands

GSM (operates on 900 MHz)

DCS (operates on 1800 MHz)

PCS (operates on 1900 MHz)the

third band is used only in USA whereas the first two bands are used in

the rest of the world. band switching is done bye a "ceramic antennaswitch" it reads from the radiation dispersed in the air and then


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switches to the appropriate band.

in the very first phase of mobile

phones there were single band handsets which operated on singlefrequency band but now a days all the handsets are dual band or tri

band in operation.

RF Power AmplifierRF power amplifier isoften called as ".PA" or"Transmitter" its functions is to amplify or

boast the power which is being transmitted to air, so may it would be

able to communicate with long distances. a typical .PA can amplify rfpower up to 0.6W or 600mW. This amount of rf power is sufficient to

communicate nearly 20 to 25 kilometers in open area, but all the PA's

are controlled by there rf signal processor, so if we are near our cell

base tower the PA of our phone will transmit low power but if we arefar away it will produce its maximum power.

Transmitting

A mobilephone's rf section is basically built around an rf IC which is often

called rf signal processor whereas in nokia it is called hagar IC in

some hand sets and in some hand sets it is called Mjoelner.

irrespectively of the brands and verity of names we call it rf signalprocessor. this IC works as transmitter and receiver as well. working

as transmitter it takes instructions from phone's computer and also

takes audio data from audio section and creates radio waves then mixesaudio data to its radio waves according to the instructions given by

computer section. this mixer of audio and radio is sent to PA to

amplify its strength

RecieverA reciver section for rf waves is

built in rf IC, as it is said that this IC works for dual purposes

first transmitting and section recieving. in the recieving section ofmobile phones a radio signal is gather from ceramic antenna switch and

then it is filtered and sent to rf IC to further process. in rf IC

signal is detected and then rectified for audio and data which is sentto audio IC or computer section.

Computer Section:

A computer section in mobile phone consists of two main functions

CPU(central processing unit) Memory (RAM, FLASH, COMBO CHIP)

CPU:

A

CPU is used in mobile phones as a central processing arithematic orcontroler. the cpu controls various functions in mobile phones like

signal, display, sound converting(DSP), charging, power on, rf channel

controler, rf tx power conroller, LEDs, vibrator, data processing, datastoring etc. so we can say that if a cpu is damaged in any mobile phone


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it cannot be repaired unless the CPU is not replaced but this type of

fault is not even seen to me ever either memory chips can be damaged.

in brand Nokia CPU is named with two different words (MAD or UPP)Memory:

there are two main types of memories used in mobile phones

RAM (Random Access Memory)TheRAM is used in mobile phones to store user data in mobile phones. So

these a days we can store pictures, messages, ringtones, applications,

themes and other these type of things in mobile phones so CPU storesthese types of data in the RAM of our mobile phones.

Flash (eeprom, ROM etc)

The

flash chip is used in mobile phones to hold mobile phone's operatingsystem in it. so if the flash chip is damaged in mobile phones the

phone cannot power on properly because all the instructions to start a

mobile phones and its various tasks like call making , display etc arestored in the flash chip of mobile phones.

Combo Chip

In smoe

mobile phones there is a combined type of memory used which is calledcombo memory chips these types of memories work for both like RAM and

Flash.The clear example of this type of memory is used in Nokia 1100.

Note: Multy Media Cards are not a part of mobile phones because they are used externally.

Mother Board System

This

Lesson is intended to make you aware of the Fundamentals of a mobile

phone's mother board and I want to teach you about what a typicalmother board.

A typical mother board is constructed using two main things Fiber Plate

Copper Plate

These two plates are joined in three forms.

Single layer board Double layer board

Three or tripple layer board

A

single layer board is constructed yusing one copper plate and the otherfiber plate. Its one side is copper faced and other is fiber faced.

while

a Double layer board is made with two copper sheets ad fiber sheet.Itsone side is copper faced and the other is also copper faced and the


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fiber is stcked between two copper sheets.this kind of board holds

electronic components on both of its side because both copper sided

prints anre inter connected with one another on proper placesA three layer board is made with three copper sheets and two fiber sheet.as it is shown below.

Basics about Mother Boards

Differentmother boards have different views but many things are common indifferent brand mother boards.first common thing is ,every mother board

has radio Section on top of the mother board

A typical mobile phone has various types of faults which can be distributed in two main kinds of

faults

Hardware faults

Software faults Setting Faults

Hardware Faults:

Hardwarefaults in mobile phones are related to mother boards of mobile phone,

batteries and any physical fault will be amount to hardware faults. I

have pointed out as much hardware faults as much i remeber this time

but if you have a fault which is not listed below you can tell me byclicking here I willo be glad to know that it would be a great help for

me too.The list of common hardwarefaults is given below.

dead set condition no charging

battery empty

auto charging

low signal No signal

voice problem

vibrator problem ringer problem

backlight problem

auto turn off hanging problem

insert sim (no sim card inserted shows on the screen)

keypad problem

display problemSoftware problems:

hanging problem

no signal

dead set display

contact service (contact retailer, contact service provider)

Test mode not charging


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Setting problem:

call divert

sim lock security code

country lock

cnfiguration of SMS configuration of GPRS configuration of call

Filters .antenna Switch .. What Are They?

Antenna

Switches are used in Mobile Phones extensively at the very first stage

of the point of entry of the signal (called the received signal Rx)into the mobile phone which also eventually becomes the point of exit

for the outgoing signal or the transmitted signal Tx.

ANTENNA SWITCH .. FILTERS .WHAT ARE THEY?

ANTENNA

SWITCHES OR DIPLEXERS ARE DEVICES WHICH transmit and receive on thesame antenna at the same time, reject unwanted signals and feed two

different signals to the same antenna.

(ANTENNA SWITCH IS ALSO KNOWN AS A DIPLEXER ! )

The

common application for a diplexer is to connect a dual band mobileradio's two antenna connections to a common feed line and antenna. A

diplexer is a simple high and low pass filter connected together. The

filters are explained in detail below.

Diplexers are

three-terminal frequency-dependent devices that can be used as aseparator or a combiner of signals. It can have more than three

terminals also. The device consists of two fixed tuned bandpass filters

sharing a common port. The common port and the output of the two

filters (RX and TX) form the three terminals of the diplexer. Signalsapplied to common port are separated in accordance with their passband

frequencies of the filters. Signals applied to either uncommon port are

isolated from the other uncommon port and are combined at the common

port.

As

is common knowledge, a FILTER is a device which removes unwanted itemsfrom a mix and provides us with a finished product which is a pure


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final product of our requirement.

Electronic filters areelectronic circuits which carry out the signal processing functions,

specifically intended to enhance wanted signal components and/or remove

unwanted ones.

SAW (surface acoustic wave) filters are

electromechanical devices commonly used in radio frequency

applications. Electrical signals are converted to a mechanical wave ina piezoelectric crystal; this wave is delayed as it propagates across

the crystal, before being converted back to an electrical signal by

further electrodes. The delayed outputs are recombined to produce a

direct analog implementation of a finite impulse response filter. Thishybrid filtering technique is also found in an analog sampled filter.

Passivefilters :The simplest electronic linear filters are based on

combinations of resistors, inductors and capacitors. These filters

exist in so-called RC,LC,RL, and RLC varieties. All these types are

collectively known as passive filters, because they do not depend uponan external power supply. Inductors block high-frequency signals and

conduct low-frequency signals, while capacitors do the reverse. A

filter in which the signal passes through an inductor, or in which acapacitor provides a path to earth, therefore presents less attenuation

to low-frequency signals than high-frequency signals and is a low-pass

filter. If the signal passes through a capacitor, or has a path to

ground through an inductor, then the filter presents less attenuationto high-frequency signals than low-frequency signals and is a high-pass

filter. Resistors on their own have no frequency-selective properties,

but are added to inductors and capacitors to determine thetime-constants of the circuit, and therefore the frequencies to which

it responds.

At very high frequencies (above about 100 megahertz ormegacycles.), sometimes the inductors consist of single loops or strips

of sheet metal, and the capacitors consist of adjacent strips of metal.

These are called stubs.

Active filters: Active filters are made upby using a combination of passive and active (amplifying) components.

Amplifiers are frequently used in active filter designs. These can have

high selectivity, and achieve the desired selectivity without the use

of inductors. However, their upper frequency limit is limited by thebandwidth of the amplifiers used.

Generally, each family of filters

can be assigned a particular order. The higher the order, the more thefilter will approach the "perfect" filter of complete transmission in


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the pass band, and complete attenuation in the stop band.

Each

family can be used to specify a particular pass band in whichfrequencies are transmitted, while frequencies outside the pass band

are more or less attenuated.

Low-pass filter - Low frequencies are passed, high frequencies are attenuated. High-pass filter - High frequencies are passed, Low frequencies are attenuated. Band-pass filter- Only frequencies in a frequency band are passed.

Band-stop filter - Only frequencies in a frequency band are attenuated.

All-pass filter - All frequencies are passed, but the phase of the output is modified.

An analogue filter handles analogue signals or continuous-time signals,

whether electric potential, sound waves, or mechanical motion directly.

This is opposed to a digital filter that operates on discrete-timesignals. Older analog filters (newer filters are digital filters) work

entirely in the analog realm and must rely on physical networks of

electronic components (such as resistors, capacitors, transistors,etc.) to achieve a desired filtering effect.

Passive filter: A

passive component is an electronic component that does not require a

source of energy to perform its intended function. Examples of passivecomponents include resistors, capacitors, and inductors.

A passive filter is an electronic filter made entirely from passive components.

Activefilter: An Active filter is the one which involves active component

that make use of a semi-conductor device like a transistor, an

electronic device that requires a source of energy to perform its

intended function.A active component is one that can be used to

provide gain or an amolification of the signal in an electronic

circuit. It contains mainly semiconductor devices like diodes andtransistors.

Digital filter : A digital filter is any electronicfilter that works by performing digital math operations on an

intermediate form of a signal.

Digital filters can easily achieve

performance metrics far beyond what is (even theoretically) possiblewith analog filters. It is not particularly difficult, for example, to

create a 1000Hz low-pass filter which can achieve near-perfect

transmission of a 999Hz input while entirely blocking a 1001Hz signal.

Analog filters cannot split apart such closely spaced signals.Also,

for complex multi-stage filtering operations, digital filters have the

potential to attain much better signal to noise ratios (more of desiredsignal in comparision to unwanted signals) than analog filters. This is


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because whereas at each intermediate stage the analog filter adds more

noise to the signal, the digital filter performs noiseless math

operations at each intermediate step in the transform. The primarysource of noise in a digital filter is found in the initial analog to

digital conversion step, where in addition to any circuit noise

introduced, the signal is subject to an unavoidable selectivity errordue to the finite resolution of the digital representation of thesignal.

Digital filters can achieve virtually any filtering effect

that can be expressed as a mathematical algorithm. The two primarylimitations of digital filters are their speed (the filter can't

operate any faster than the computer at the heart of the filter), and

their cost. However as the cost of integrated circuits have continued

to drop over time, digital filters have become increasingly commonplaceand are now an essential element of many everyday objects such as

radios, cellphones, and stereo receivers. Digital filters can easily

achieve performance levels far more than what is (even theoretically)possible with analog filters. It is not particularly difficult, for

example, to create a 1KHz low-pass filter which can achieve

near-perfect transmission of a 0.999KHz input while entirely blocking a

1.001KHz signal. Analog filters cannot split apart such closely spacedsignals.

Mobile Phones make use of Filters called Dual Band-pass

filters because they need to allow two frequencies of signals mostcommonly 900MHz and 1800MHz in the dual band mobile phones. Also

Antenna Switches are used in Mobile Phones expensively at the very

first stage of the point of entry of the signal (called the received

signal Rx) into the mobile phone which also eventually becomes thepoint of exit for the outgoing signal or the transmitted signal Tx. The

newer models of the Mobile Phones like a Nokia 6600 makes use of an

active Antenna Switch which also has a built-in amplifier circuitinside it to immediately boost the Rx signal.

Introduction To Mobile Phone Parts.docx

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