Although the Kirin 9000 chip integrates 5G baseband, it cannot get the necessary RF chip for 5G mobile phones after Huawei was sanctioned.
Specifically, there is an important part of the mobile phone motherboard called " Rf chip combination " , burdened with cell phone signal reception and transmission. Without this part, mobile phones are disconnected from the Internet. Single machine " .
At present, the international RF chip market is occupied by the United States and Japan, and localization is difficult. Huawei had previously purchased radio frequency chips from Skyworks of the United States, but after sanctions were imposed in 2018, it began purchasing from NXP of the Netherlands and Murata of Japan.
In April 2021, the United States began the fourth round of sanctions against Huawei, requiring all supply chain companies involved in U.S. technology not to provide components to Huawei's 5G communications equipment, including 5G radio frequency chip combinations and 5G baseband. As a first-class chip design capability, Hisilicon has begun to overcome some components of RF components in the early years, but the core filter has not yet been overcome.
There is no 5g chip component, mainly controlled by the United States, which does not provide 5g chips, only 4g chips, so Huawei 9000 chips can only be used as 4g
Because of U.S. sanctions, 5g contains American technology, and radio frequency chips cannot be bought, so 5g cannot be used