A Compact Coupled-Fed Loop Antenna for Mobile LTE Smartphones

Abstract

A coupled-fed loop antenna with Octa-bands operation for long-term evolution (LTE) smartphones is proposed in this paper. The antenna occupies a nonground space of only 6.5 mm × 72 mm, and two wide-band operations can be achieved by exploiting the multimode characteristics of loop antenna and using high-pass matching circuits. In low band, the LTE700/GSM850/900 operation is achieved by the loop mode of 0.5 λ and matching chip capacitor which generates a dual-resonance mode at 0.74 GHz and 0.9 GHz. In high band, the 1 λ mode, the 1.5 λ mode, and the 2 λ mode of the entire loop are combined with the 0.5 λ mode of the left-side coupling loop to cover the DCS1800/PCS1900/UMTS 2100/LTE 2300/2500 operation bands. The measured average realized gains and efficiencies are approximately 1.56 dBi/2.38 dBi and 55.3%/63.6% in the two bands, and a good radiation pattern is achieved as well.

A Frequency Reconfigurable Compact Planar Inverted-F Antenna for Portable Devices

“…e antenna became lossy due to large number of varactor diodes and had large antenna size. In another work [15], a coupled-fed loop antenna to cover octa-band for LTE smartphone was proposed. Low modes were achieved with the combination of loop mode of 0.5λ and chip capacitor, and the antenna was operating at the high band by using the combination of 1λ, 1.5λ, and 2λ modes with 0.5λ mode of coupling loop.…”

A Compact Wideband Printed Antenna for 4G/5G/WLAN Wireless Applications

“…Recently, various techniques have been proposed for the design of the multiband or broadband antenna. Several printed wideband antennas for mobile phones have been proposed in the literature [1][2][3][4][5][6]. However, in order to cover the LTE/ WWAN (Wireless Wide Area Network) operation in the 700 MHz band, the radiating board in the printed monopole occupies a large volume, which may be folded to achieve a compact size in the mobile phone.…”

Nona‐band, hybrid antenna for metal‐rimmed smartphone applications

“…All of the aforementioned evolutions have been reflected in the development of mobile phone antennas in order to meet the requirements of the great industrial and technological advances. For instance, the high demand on compact and multiband antennas to support various wireless applications has led to the development of several antenna structures such as slot antennas [2][3][4][5], monopole antennas [6][7][8][9][10], loop antennas [11][12][13][14], and planar inverted-F antenna [15,16].…”