Investigation of DCS1800/TD-LTE dual-mode and dual-link UE system performance based on the high isolation handset antenna

This paper investigates the performance of DCS1800/TD-LTE dual-mode and dual-link (DM-DL) UE, and presents an effective solution based on our designed high isolation antenna for the UE local electromagnetic interference (EMI). Firstly, we bring out a DCS1800/TD-LTE DM-DL UE system model, together with its interference analysis and performance evaluation. It is revealed that the receiving sensitivity of TD-LTE can be greatly interfered by the DCS1800 local interference. To alleviate this DCS1800 local interference, then, a compact and high isolation double-band handset antenna is given with its structure designed and performance validated. On the basis of this antenna and existing bandpass filter, we introduce a solution called "passive isolation" to solve the DM-DL co-existence issue. Finally, we research the performance of DCS1800/TD-LTE DM-DL UE again by our proposed solution. Simulated results indicate that the isolation effect is quite good and the DM-DL UE can work unaffectedly.