Reconfigurable narrow‐frame antenna for LTE/WWAN metal‐rimmed smartphone applications

Abstract

A reconfigurable narrow‐frame coupled‐loop antenna capable of providing hepta‐band long term evolution/wireless wide area network (LTE/WWAN) for metal‐rimmed smartphone applications is proposed. The ground clearance of this proposed antenna is only 7 × 70 mm2 which is promising for narrow‐frame smartphone applications. Moreover, this proposed antenna can realise the miniaturisation by employing a positive intrinsic negative diode (PIN diode), which can provide two working states. When the PIN diode is OFF, it can provide coverage for GSM850/DCS/PCS/UMTS2100/LTE2300/2500 operations. When the PIN diode is ON, the obtained bands are GSM900/DCS/PCS/UMTS2100/LTE2300/2500. Hence, by combining these two working states, GSM850/900/DCS/PCS/UMTS2100/LTE2300/2500 operations are achieved. In addition, the feasibility of realising decoupled multi‐antennas is demonstrated and its performances are well‐suited for future smartphone applications. Detailed design considerations of the proposed antenna are described. Both experimental and simulated results are also presented and discussed.

Carrier Aggregation Compatible Mimo Antenna for Lte Handset

“…The efficiency performances of the proposed main and diversity antennas can be compared to some of the MIMO handset antennas presented in recent literature [7,8,23,24]. For the four-element MIMO design given in [7], the measured efficiency is from −2.2 to −4 dB at the low band, but no HB results are given.…”

“…Examples of MIMO antennas with tunable matching circuits are given in, e.g., [8,24]. The twoelement design of [8] achieves an efficiency of −1.5 to −4 dB at both LB and HB.…”

“…The twoelement design of [8] achieves an efficiency of −1.5 to −4 dB at both LB and HB. However, as mentioned previously, the LB starts only from the 800-MHz range, meaning that the most challenging LTE LB frequencies are missing even with tuning.…”

“…Recent multi-element handset antenna designs can be found in, e.g., [7][8][9][10]. The design presented in [7] implements a four-element MIMO antenna for the low band (LB) (698-960 MHz), but the study does not consider high band (HB) MIMO.…”

“…The design presented in [7] implements a four-element MIMO antenna for the low band (LB) (698-960 MHz), but the study does not consider high band (HB) MIMO. On the other hand, the work of [8] features both LB and HB MIMO, and different frequency bands starting from the 800-MHz range are covered using a diode switch.…”