RF frontend, 5G,Apple: Elaboration on iPhone 12 5G antennas

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RF frontend, 5G,Apple

With the Apple iPhone 12 series, we have a discovered a 5G mmWave system like we have never seen before. The system is built for high-speed communication with human safety consideration all controlled by only one chipset. For the first time, the mmWave transceiver (RxTx) is separated from the antenna array in the design. Indeed, this chipset comprise several types of devices: a modem, an intermediate frequency (IF) IC, a front-end module (FEM), two antenna arrays and an Antenna-in-Package (AiP). For human safety, an ISM radar working in the 24 GHz frequency band is implemented. The radar detects any human body in order to limit the radiation from the 5G mmWave communication system when a body is present. This radar system uses an antenna on flex design (radar antenna) controlled by a FEM packaged by Murata. The Murata FEM adjust the amount of radiation sent to the rear facing 5G mmWave antenna based on the radar signals it receives from the radar antenna. The rear facing 5G mmWave antenna is a system of 16 passive antenna built on an 8-layer PCB substrate. Only 10 % of the bumps connect to the main board. At the side of the phone, a traditional AiP (Antenna in Package) is integrated in the frame for side communication. This AiP is very similar to the Qualcomm’s devices (QTM525 and QTM535) used in other 5G mmWave products. The only differences are in the size of the module and the design of the antenna. By using USI or Murata for the packaging, Apple managed to lower the width by 12 points and the length by 7 points with the same z-height (compared the last QTM535 from Qualcomm). Although, a question remains, why only half of the I/O is used on the RxTx? As in the AiP design, Qualcomm supplies all of the Ics (integrated circuits) in this 5G mmWave system. The Modem, and the IF IC are exposed on the board and are clearly identifiable as Qualcomm. But the RxTx and the power management IC (PMICs),which are in the Murata FEM, are not exposed for easy identification. X-ray observations has given the identity of these ICS. The RxTx and the PMIC seem to be exactly the same as the ICS implemented in the AiPs (QTM525 and QTM535). The impact of this supply chain is more on the packaging manufacturer. Indeed, for the QTM535 or QTM525, SPIL and Amkor were involved in the supply chain, which is not the case here. SPIL and AMKOR have been replaced by USI and Murata, which are historical packaging suppliers for Apple.