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In this video we're going to learn about the RF chips

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Radio frequency is abbreviated as RF

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In the drawing the symbol RF generally refers to the radio frequency circuit

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The main function of RF chip is to convert baseband signal into radio signal of certain frequency band

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Radio frequency chips are also called intermediate frequency chips

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In iPhone, the RF chip is mainly responsible for receiving and transmitting,

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frequency synthesis and other functions

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Basically, when we plug in the phone card,

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the phone gets a signal

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The signal and the signal strength will be sent to the RF chip,

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which is processed and then sent to the baseband

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In Apple mainboards, RF chips are generally black and square

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Some machines have only one, but some machines have two

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If there are two, they are usually called primary RF and secondary RF

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If there is only one, it is called RF chip

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After the RF chip is damaged, many problems are caused

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Common problems such as mobile phone display no service,

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weak signal, loop jump card

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Problems like these can be caused by RF damage

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Rf damage is a common problem in iPhones

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When replacing, the same model should be replaced,

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because the RF chip is different for different models

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Now, let's look at the RF chip in real life

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The mainboard is an iPhone 7 mainboard,

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and its RF chip is located on the bottom of the mainboard

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It has two RF chips, one slightly larger and one slightly smaller

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Sometimes we call them big RF and small RF

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The mainboard is an iPhone 8 mainboard,

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and its RF chip is located underneath the mainboard

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This model has only one RF,

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which is square with a black surface

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From the iPhone 7 to iPhone x Intel baseband, they will have two radio frequencies

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This mainboard is from iPhone 8, Intel baseband

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It's going to have two radio frequencies,

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one here and one here

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There is a layer of glue on this surface,

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and when you peel it off, it is black

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This mainboard is a XR mainboard,

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which also uses Intel baseband

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But it has only one RF chip, below the baseband,

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with a black surface

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In the dual-layer mainboard,

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the RF is generally located in the lower layer of the mainboard

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This is the iPhone 11 mainboard,

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and the RF is in the lower part of the mainboard, at the bottom

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This chip is the iPhone 11's RF chip

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So that's it for this lesson