Apple 5G – Antenna issues

mmWave antenna design is still a big issue.

• As I have long suspected, one of the most challenging issues for 5G is the design of the mmWave antenna which has very little margin for error and has to deal with the most challenging radio propagation conditions yet seen in mobile telephony.
• Currently, Qualcomm is the only game in town for mmWave baseband chips and it also sells a QTM525 antenna to work with its baseband.
• Apple appears to be to trying to design its own antenna (see here) to work with Qualcomm’s 5G baseband which I suspect is for two reasons.
  • First, form factor: According to the report, the QTM525 design makes it impossible to fit into the sleek design that Apple wants for the iPhone 12.
  • Qualcomm stated that the QTM525 will fit in designs which are less than 8mm and given that the iPhone 11 is 8.1mm thick, I can’t really see why this should be a problem.
  • Hence, I suspect that this more about having as few Qualcomm parts as possible.
  • Second, dispute: Apple is still sore from the crushing defeat that Qualcomm dealt it in April 2019 (see here) as it still believes that Qualcomm is overcharging it for its IP.
  • This resentment led Apple to sign a shorter licence agreement than usual with Qualcomm (6 years) and also to acquire Intel’s modem business in an attempt to design its own baseband.
  • In the meantime, it is forced to use Qualcomm chips if it wants to have a 5G phone which it has decided that it must launch this year.
  • I am not 100% convinced that Apple will lose out to Samsung or anyone else if it does not launch a 5G phone this year but that is another debate.
  • Qualcomm also sells a large number of components that partner with the baseband to make a complete radio system and it is these parts that Apple is trying to get rid of.
• 5G mmWave antennas are difficult because while the high frequencies involved allow the antennas to be very small, they have to be very high precision or else they won’t work properly.
• Furthermore, the QTM525 will have been designed to work optimally with Qualcomm’s baseband and matching that performance will not be easy.
• I suspect that Apple is not actually designing this antenna itself but rather has gone outside to procure a custom antenna.
• It may even have asked Qualcomm to design it a custom antenna as there are specific radio issues that arise when one uses a metal case for a phone.
• In the fullness of time, I expect Apple to come out with a full radio solution for its own devices.
• The fact that the WiFi on the iPhone 11 really struggles in weak signal conditions related to almost any other device that has a plastic case is evidence of the issues that metal-cased devices face when it comes to radio.
• The net result is that antenna design remains one of the hottest areas for mmWave 5G and one where I suspect good money will be made.
• Apple has had antenna problems before and will not be eager to repeat them.