Compact Antenna for 4G/5G Metal Frame Mobile Phone Applications Using a Tuning Line

Abstract

A compact antenna with a 6 mm ground clearance for 4G and 5G metal frame mobile phones is proposed in this paper. The proposed antenna consists of a coupled line, a ground branch, a monopole branch, and a tuning line. The ground branch and the coupled line are used to obtain the lower band (698–960 MHz), the monopole branch is used to improve the match at the lower band and obtain the higher band (1710–2690, 3400–3800 MHz), and the tuning line is used to improve the match at the higher band. The novelty of the proposed antenna is that more modes are excited and work together to obtain multiple working bands, by using the coupled line and the folded branches with the help of the tuning line, and then nine bands are obtained under the conditions of a 6 mm, only, ground clearance and a metal frame environment. A prototype has been fabricated and measured. The measured −6 dB impedance bandwidths are 345 MHz (0.685–1.03 GHz) and 2.16 GHz (1.67–3.83 GHz) at the lower and higher bands, respectively. The LTE700, GSM850, GSM900, DCS, PCS, UMTS, LTE2300, and LTE2500 bands for 2G, 3G, 4G, and the 3.5 GHz band that is possible for 5G are covered. The measured efficiencies and patterns are also presented.

Compact thirteen‐band antenna for 4G/5G/WLAN metal frame mobile phones

“…In recent years, many wideband antennas for mobile phones are presented. To make the antennas for mobile phones with small ground clearances and cover multiple bands, some methods are proposed and studied, such as using match circuits to emerge more new resonant frequencies to make the bandwidth wider, using multiple branches to excite more working modes, and using reconfigurable means to increase the working bands at different time. The ground clearances of the antennas proposed by References , are not bigger than 5 mm, but the LTE700 band, the possible 5G bands, and the WLAN bands at about 5 GHz are not achieved.…”

“…The LTE700 band is achieved by the antennas in References , but their ground clearances except that of the antenna in Reference are not smaller than 6 mm. The antennas in References , cannot cover the possible 5G bands and the WLAN bands at about 5 GHz.…”

“…The antennas in References , cannot cover the possible 5G bands and the WLAN bands at about 5 GHz. Although the antennas in References can cover the 3.5 GHz band for 5G system, but cannot cover the 4.8 GHz band for 5G system and the WLAN bands at about 5 GHz. Although the ground clearance of the antenna in Reference is only 2 mm, but the possible 5G bands and the WLAN bands at about 5 GHz are not covered.…”

“…The merit of the antenna proposed in this article is that it can cover 13 bands under the condition of a metal frame environment and a 7 mm ground clearance. Compared with the antennas in References proposed by us, the proposed antenna has the advantages of more working bands by fully using the possible modes of each branch and making them work together by only using a coupled feeding line, and less cuts when there are metal frames. Table gives some antennas for metal frame mobile phones, including some important factors such as the dimension, working frequency band, ground clearance, and the measured efficiency.…”

“…Table gives some antennas for metal frame mobile phones, including some important factors such as the dimension, working frequency band, ground clearance, and the measured efficiency. According to Table , many antennas , can cover the bands of 698 to 960 MHz and 1710 to 2690 MHz, and the smallest ground clearance of these antennas except the antenna in Reference is 6 mm. The antenna proposed in this article can cover the bands of 698 to 960 MHz, 1710 to 2690 MHz, 3300 to 3800 MHz, and 4600 to 5850 MHz with a 7 mm ground clearance.…”