Smart phone antenna tuning

Smartphones now support more and more frequency bands ,2G/3G/4G/5G Add up to dozens of frequency bands . typically 2G BC0/B2/B3/B5/B8,3G BC0/B1/B2/B5/B8,4G B1/B2/B3/B4/B5/B7/B8/B34/B38/B39/B40/B41,5G n1/n3/n5/n8/n28A/n41/n78/n79. In addition to more frequency bands , Smartphones support more and more functions , Especially the functions strongly related to the antenna , Like carrier aggregation ,MIMO. meanwhile , Smart phones are limited by appearance and structure , The space left for the antenna becomes smaller . These factors add up , It poses a greater challenge to the antenna design of smart phones .

In order to improve the efficiency of the antenna and achieve better performance ( Include TRP and TIS), Antenna tuning of smart phones is essential . There are mainly two ways of antenna tuning , Aperture tuning (Aperture Tuning) And impedance tuning (Impedance Tuning). Aperture tuning mainly improves the efficiency of the antenna , Impedance tuning mainly reduces the loss caused by impedance mismatch . Currently, smart phones mainly adopt aperture tuning method , Among them, high-end smart phones use aperture and impedance tuning combination method , This can get better performance .

The figure above shows the difference between aperture tuning and impedance tuning , It can be seen that the difference between the two methods lies in the different positions of the tuning devices .

For aperture tuning , from Qovro We can see the data of , When adjusting different inductance or capacitance values of the tuner , The efficiency of the antenna will be different . At the same time, if the tuner is placed in a different position , For example, the position shown in the figure below A And location B, They are different from the feed point , You will also get different antenna efficiency .

For impedance tuning , from Qovro B5 The performance data can be seen , If impedance mismatch occurs ,B5 There will be large loss. According to the specific frequency ,loss from 0.9dB To 2.9dB Unequal . If the impedance is increased after tuning ,loss Will be significantly reduced .

reference ：

1. About 4G/5G Smart phone antenna tuning 4 Point instructions - Qorvo
2. Qovro,《QUICK GUIDE: Aperture Tuning》
3. Qovro,《WHITE PAPER: Applying Impedance Tuning to Maximize Antenna Performance in 5G Phones》