Fourth generation iPhone. Repair is straightforward, but the front glass and LCD must be replaced as a unit. GSM / 8, 16, or 32 GB capacity / Model A1332 / Black and White.

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What is the pressure contact under the back panel for?

Everyone's heard about (or experienced) the RF signal attenuation that occurs with the new iPhone 4, but how exactly is the stainless steel band attached to the internal circuits to be used as the antenna. Most interestingly, I was reading through the iPhone 4 Battery Repair Guide on the site and noticed that Step 6 refers to the pressure contact as being part of the antenna system! Is this true? Is there more to the antenna system behind the glass panel on the back? I'd investigate myself, but I don't want to risk ruining my new iPhone 4 :( I was hoping someone could post a teardown of the antenna system just so we could all get a better understanding of how it works.

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apple also cooks with water - the antenna contact is for the antenna in the backplate

CLICK and CLICK

the antenna system is almost "boring" - sorry to say that.

they needed to cover all receivable frequencies:

  • UMTS/HSDPA/HSUPA (850, 900, 1900, 2100 MHz)
  • GSM/EDGE (850, 900, 1800, 1900 MHz)
  • 802.11b/g/n Wi-Fi (802.11n 2.4GHz only)
  • Bluetooth 2.1 + EDR wireless technology

+ the gps antenna

the materials used on the iPhone 4 are not the best ones to be used on a phone, so they had to tinker a little bit to get it halfway done ;-)

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Very interesting... Do you think that the antenna hidden in the backplate is enough to get the job done? I am curious to see if disconnecting the UMTS/GSM antenna system to the frame could fix the signal attenuation issue by only relying on that backplate antenna. Is there a way to try this?

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I'm assuming this backplate antenna is a multi-band fractal antenna, so it would be able to cover all the possible GSM/UMTS frequencies. The stainless steel band could only cover one frequency, determined by its length, right? I'm not really an antenna expert, so I'm probably wrong... but I do have an associates degree in engineering :P

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there are many ways to get it done, it depends on the antenna design, double frequency = half antenna lenght and so on, you can read this - but there are many documents about this topic on the net - have fun ;-)

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Looks like an interesting read! Thanks again!

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Josh Hawn will be eternally grateful.
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