Yong-Ling Ban

A Dual-Loop Antenna Design for Hepta-Band WWAN/LTE Metal-Rimmed Smartphone Applications

A simple direct-fed dual-loop antenna capable of providing hepta-band WWAN/LTE operation under surroundings of an unbroken metal rim in smartphone applications is proposed. The greatest highlight of this proposed antenna is that it provides a simple and effective multiband antenna solution for an unbroken metal-rimmed smartphone. The unbroken metal rim with 5 mm in height embraces the system circuit board of 130 × 70 mm2. Two no-ground portions of 10 × 70 mm2 and 5 × 70 mm2 are set on the top and bottom edge of the system circuit board, respectively. In-between the two separate no-ground portions, there is a system ground of 115 × 70 mm2 connected with the unbroken metal rim via a small grounded patch which divides the unbroken metal rim into two strips. Finally, a dual-loop antenna is formed by combining the inner system ground and two strips. This proposed dual-loop antenna is capable of covering GSM850/900/DCS/PCS/UMTS2100/LTE 2300/2500 operating bands. Detailed design considerations of the proposed antenna are described and both experimental and simulation results are also presented and discussed.

Low-Profile Printed Octa-Band LTE/WWAN Mobile Phone Antenna Using Embedded Parallel Resonant Structure

A simple low-profile antenna for octa-band LTE/WWAN operation in the internal mobile phone application is proposed and studied in this article. Consisting of a feeding strip and a coupling strip mainly, the presented antenna can be easily printed on the no-ground area of the top of a FR4 substrate, yet it occupies only a size of 15 × 40 mm2 and has a height of 3.5 mm. In this scheme, a chip inductor (L1 = 20 nH) is loaded in the long inductive strip, which can form a parallel resonant structure together with the coupling strip section close to the feeding strip. With these presences, a double-resonance mode (λ/4 resonant mode) is successfully generated at about 720 and 900 MHz to cover the lower band of LTE700/GSM850/900 (704-960 MHz). While the desired upper band of DCS1800/PCS1900/UMTS2100/LTE2300/2500 (1710-2690 MHz) can be obtained with the help of second two resonant modes, including a high-order λ/2 resonant mode at 1800 MHz and a λ/4 resonant mode at 2550 MHz. That is to say that those two wide operating bandwidths are achieved to cover all the octa-band LTE/WWAN operation. Good radiation efficiency and antenna gain for frequencies over the desired operating bands is obtained. Detailed design considerations of the proposed antenna are described, and both experimental and simulation results are also presented and discussed.

Bandwidth Enhancement of LTE/WWAN Printed Mobile Phone Antenna Using Slotted Ground Structure

In this article, a coupled-fed planar printed antenna mounted on the compact no-ground portion of the system circuit board of a mobile phone with a low proflle of 10mm is proposed and studied. The presented antenna is formed by a double-branch feeding strip, a shorted coupling strip with two open-ended loops of difierent lengths, and a slotted ground structure consisting of two monopole slots, yet it has a size only 15 £ 50mm 2 . Two wide operating bandwidths of 698{960MHz and 1710{2690MHz can be achieved by these radiating strips, which provide multiple resonant modes at about 750, 1000, 1750, 2300 and 2900MHz. In addition, with the presence of the two narrow slots and a chip inductor (L = 1:5nH), in this study, the printed antenna can lead to much widened bandwidths in both the antennas lower and upper bands to cover LTE700/GSM850/900 and DCS1800/PCS1900/UMTS2100/LTE2300/2500, respectively. Good radiation e-ciency and antenna gain for frequencies over the desired operating bands are obtained. Detailed design considerations of the proposed antenna are described, and both experimental and simulated results are also presented and discussed.

Compact Eight-Band Frequency Reconfigurable Antenna for LTE/WWAN Tablet Computer Applications

A novel eight-band LTE/WWAN frequency reconfigurable antenna for tablet computer applications is proposed in this communication. With a small dimension of 40 × 12 × 4 mm3, the proposed antenna comprises a loop feeding strip and a shorting strip in which a single-pole four-throw RF switch is embedded. The RF switch is used to change the resonant modes of lower band among four different working states, so that the antenna can provide a multiband operation of LTE700/GSM850 /900/1800/1900/UMTS2100/LTE2300/2500 with return loss better than 6 dB. Reasonably good radiating efficiency and antenna gain are also achieved for the practical tablet computer.

Printed Coupled-Fed PIFA for Seven-Band GSM/UMTS/LTE WWAN Mobile Phone

A planar printed PIFA is proposed and fabricated in this work, which is promising for internal mobile applications. In the design, the presented antenna consists of a feeding strip and a coupling strip (which is short-circuited to the system ground by a long shorting strip). By the coupled-fed excitation, the proposed antenna can generate multiple resonant modes at lower and upper bands for seven-band WWAN operation, covering GSM850/900/DCS1800/PCS1900/UMTS2100/LTE2300/2500. In detail, the feeding strip can excite high frequency current distributions on the coupling strip by a coupling gap to generate a fundamental resonant mode at around 800 MHz, while the desired upper resonant modes at about 1850 MHz and 2550 MHz can be achieved by the feeding strip itself. The proposed antenna occupies a size of 15 × 45 mm2 and is easily printed on one surface of a FR4 substrate as system circuit board, which makes it suitable for practical mobile applications. Finally, the simulated and measured results are given, which obtain good agreement and illuminate the reliability of the scheme.

Small-Size Coupled-Fed Antenna With Two Printed Distributed Inductors for Seven-Band WWAN/LTE Mobile Handset

A compact small-size coupled-fed antenna with two symmetrical printed meandered inductive strips as two distributed inductors for seven-band operation covering the GSM850/900/1800//1900/UMTS2100/LTE2300/2500 bands in the internal mobile handset application is proposed. Wideband operation is achieved by incorporating a feeding strip and two radiating strips of different lengths, which are both disposed on the no-ground board space of the proposed antenna. The desired lower bands of GSM850/900 operation can be achieved by the two radiating strips of different lengths, which provide a quarter-wavelength dual-resonance mode at 810 and 962 MHz. While the feeding strip can provide a quarter-wavelength resonant mode at around 1.78 GHz, and other resonant modes at 2.45 GHz are contributed by the higher-order resonant modes of the two radiating strips, covering the desired upper bands of DCS1800/PCS1900/UMTS2100/LTE2300/2500 operation. In addition, the proposed antenna only occupies a planar size of 15×30 mm2 and is easily printed on one surface of a FR4 substrate, which makes it suitable for practical mobile applications. Detailed considerations of the design and main parameters are studied in this communication and the proposed antenna is successfully simulated, fabricated, and measured.

Decoupled Planar WWAN Antennas With T-Shaped Protruded Ground for Smartphone Applications

A planar antenna array composed of two decoupled multiband wireless wide area network (WWAN) antenna elements for slim mobile phone application is presented and studied in this letter. A wide T-shaped protruded ground is deliberately designed to enhance the impedance matching and decouple the two closely deposed antenna elements. The integrity of the proposed T-shaped decoupling structure allows the reuse of space in between the antenna elements in the real applications. With small size occupation, the proposed antenna array covers two wide operating bands including 824-960 and 1710-2170 MHz, and within a short separating distance it achieves isolation better than 12 dB in the lower band and 15 dB in upper band. A prototype is fabricated, and the arrays overall performances are measured and compared to simulated results to validate the proposed solution.

Decoupled Hepta-Band Antenna Array for WWAN/LTE Smartphone Applications

A wideband antenna array incorporating a neutralization line (NL) for port decoupling for smartphone applications is proposed. The U-shape NL is employed to achieve enhanced isolations for the lower band, which are better than 10 dB for 824-960 MHz. The mechanism of the NL is explained based on the S-parameters and the surface current distributions. In addition, the incorporated NL has acceptable effects on the bandwidth, while a bandstop filter and on-ground slots are utilized to realize the hepta-band coverage, covering the GSM850/900/1800/1900/UMTS/LTE2300/2500 operation. A prototype is fabricated and tested, with S-parameters, radiation efficiencies, radiation patterns, envelope correlation coefficient (ECC), and mean effective gain (MEG) presented.

Low-Profile Narrow-Frame Antenna for Seven-Band WWAN/LTE Smartphone Applications

A small-size low-profile narrow-frame antenna for seven-band WWAN/LTE operations in the internal smartphone applications is proposed. The greatest highlight of this proposed antenna is that its narrow edge has a width of only 5 mm, which is very novel for smartphone applications. Meanwhile, the proposed narrow-frame antenna has a small size of 5 × 40 mm2 and a low profile of 3 mm above the circuit board, which makes it very promising for slim smartphone applications. The proposed antenna is capable of covering GSM850/900/DCS/PCS/UMTS 2100/LTE2300/2500 operating bands. Detailed design considerations of the proposed antenna are described, and both experimental and simulation results are also presented and discussed.

Printed wideband antenna with chip-capacitor-loaded inductive strip for lte/Gsm/Umts wwan wireless usb dongle applications

This paper proposes a planar printed wideband an- tenna for eight-band LTE/GSM/UMTS WWAN wireless USB don- gle applications. An inductive shorted strip with a chip capaci- tor loaded is employed in order to improve the characteristics of small-size terminal antennas which usually have a narrow band over the LTE700/GSM850/900 (698{960MHz) operation. While the desired upper band is mainly realized by the rectangular radi- ating patch, covering DCS1800/PCS1900/UMTS2100/LTE2300/2500 (1710{2690MHz) band. Easily printed on a 0.8-mm thick FR4 di- electric substrate of size 20£70mm 2 , the proposed antenna structure occupies a compact size of 20£19mm 2 . Then the proposed design can be attached to laptop computer by the USB interface. Good radiation e-ciency and antenna gain for frequencies over the desired operating bands is obtained. Detailed design considerations of the proposed an- tenna are described, and both experimental and simulation results are also presented and discussed.