Multiband and Small Coplanar Antenna System for Wireless Handheld Devices
TL;DR: In this paper, a multiband antenna system featuring small coplanar pad elements is proposed for providing operation at the communication standards LTE700 (698-787 MHz), GSM850 (824-894 MHz) and GSM900 (880-960 MHz) at different frequency regions, including satellite positioning systems GPS (1575 MHz), Galileo L1 (1559-1591 MHz), Glonass (1592-1609 MHz).
Abstract: Multiband and small antennas are strongly demanded in current wireless handheld or portable devices that require multiband operation. Nowadays, trends are focused on exciting ground plane radiation modes in order to reduce as much as possible the volume devoted to the antenna element. This paper studies different geometries for determining which one better excites a ground plane radiation mode at different frequency regions. The results demonstrate that a non-resonant pad element attains the best tradeoff between performance and geometry complexity. A multiband antenna system featuring small coplanar pad elements is proposed for providing operation at the communication standards LTE700 (698-787 MHz), GSM850 (824-894 MHz), GSM900 (880-960 MHz), GSM1800 (1710-1880 MHz), GSM1900 (1850-1990 MHz), UMTS (1920-2170 MHz), LTE2100 (1920-2170 MHz), LTE2300 (2300-2400 MHz), LTE2500 (2500-2690 MHz) as well as at the satellite positioning systems GPS (1575 MHz), Galileo L1 (1559-1591 MHz), Glonass (1592-1609 MHz). A radiofrequency system comprising broadband matching networks is included to provide the required impedance bandwidth. Numerical results give physical insight into the behavior of the proposed planar element. A prototype is built to demonstrate the feasibility of the proposal. The proposed radiating system is appealing for the new wireless handheld devices due to its small size (153 ), planar profile, and multiband performance.
Citations
More filters
TL;DR: In this article, 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.
Abstract: 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 $\, \times \,$ 70 mm $^{2}$ . Two no-ground portions of 10 $\, \times \,$ 70 mm $^{2}$ and 5 $\, \times \,$ 70 mm $^{2}$ 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 $\, \times \,$ 70 mm $^{2}$ 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.
146 citations
Cites methods from "Multiband and Small Coplanar Antenn..."
...In [8], it has proposed a small antenna system using nonresonant planar elements for 2G, 3G, and 4G occupying about 700 mm ....
[...]
TL;DR: Due to the advantages such as multiband operation, MIMO configuration for 5G communications, high isolation, and compact structure, the proposed antenna design is attractive for 4G/5G smartphones.
Abstract: In this paper, multiband antennas based on a single ring slot are proposed for 4G/5G smartphone applications. The basic structure of the antenna is consisted of a large metal ground and an unbroken metal rim, in which a single 2 mm-wide ring slots is realized between the metal ground and rim. Here, a reconfigurable 4G antenna (820–960 and 1710–2690 MHz) is initially devised by loading multiple grounded stubs and a simple dc controlling circuit with varactor diode into the upper section of the ring slot. To further cover the sub-6 GHz spectrum (3400–3600 MHz) for future 5G communications, a four-element multi-input multi-output (MIMO) slot antennas configuration is designed by utilizing the lower section of the ring slot. A prototype antenna was fabricated, and good agreement is shown between the measured and simulated results. Due to the advantages such as multiband operation, MIMO configuration for 5G communications, high isolation, and compact structure, the proposed antenna design is attractive for 4G/5G smartphones.
120 citations
Cites background from "Multiband and Small Coplanar Antenn..."
...As the wireless mobile network has already migrated from 2G to 4G mobile technology [1]–[4], higher data transmitting rate can be acquired by utilizing higher frequency band with wider operating band....
[...]
TL;DR: In this article, an octa-band WWAN/LTE monopole antenna with a size of $80\,\text{mm} \times 8\, ǫ, Ã Ã, Ã ¼ Ã 7.8 Ã for 5.7-inch mobile phones is proposed and studied.
Abstract: An octa-band WWAN/LTE monopole antenna with a size of $80\,\text{mm} \times 8\,\text{mm} \times 5.8\,\text{mm}$ for 5.7-inch mobile phones is proposed and studied. The proposed antenna consists of a folded metal plate with a lumped-element high-pass matching circuit. The working mechanism is analyzed based on the S-parameters and the surface current distributions. The 0.25-wavelength, 0.5-wavelength, and 1-wavelength modes of the monopole antenna are excited and used. The attractive merit of the proposed antenna is that the height of the nonground portion is only 8 mm. A prototype is fabricated and measured. Its measured $-6\;\text{dB}$ impedance bandwidths are 290 MHz (0.69–0.98 GHz) and 1.11 GHz (1.63–2.74 GHz) which cover the LTE700, GSM850, GSM900, GSM1800, GSM1900, UMTS, LTE2300, and LTE2500 bands. Within the two frequency bands, good radiation performances are obtained.
68 citations
Cites background or methods from "Multiband and Small Coplanar Antenn..."
...Apart from the resonant monopole/loop/slot antenna, nonresonant antenna [22] or the combination of the resonant and nonresonant antennas [7] is also applied recently....
[...]
...By selecting the antenna types with specific working modes and applying proper matching methods, the mobile antennas in [3]–[22] covering the multiple frequency bands or a wide frequency band within a proper occupied size are very promising for practical applications....
[...]
...[5], [6], [8], [9], [16], [18], [21] or distributed-element [3]–[5], [14] matching method, the capacitive-couple-element matching method [7], [22], and the reconfigurable matching method [10] are usually introduced to further widen the bandwidth and reduce the occupied size....
[...]
TL;DR: In this paper, a small-size tablet device antenna formed by a simple folded metal plate excited by a low-band feed (direct feed with matching network) and a high-band network for the LTE/WWAN operation in the 698-960 and 1710-2690 MHz bands is presented.
Abstract: A small-size tablet device antenna formed by a simple folded metal plate excited by a low-band feed (direct feed with matching network) and a high-band feed (gap-coupled feed with matching network) for the LTE/WWAN operation in the 698–960 and 1710–2690 MHz bands is presented. The folded metal plate has a size of 3 $\, \times \,$ 5 $\, \times \,$ 30 mm $^{3}$ and is disposed in a clearance area of 10 $\, \times \,$ 30 mm $^{2}$ (300 mm $^{2}$ ) above the top edge of the device ground plane. The matching network in the low-band feed compensates for additional capacitance for the folded metal plate with a resonant length much less than 0.25 wavelength in the lower band (698–960 MHz) and enhances the antenna's impedance matching to achieve a wide lower band. The matching network in the high-band feed also enhances the antenna's impedance matching to achieve a wide higher band (1710–2690 MHz). In addition, the coupling gap in the high-band feed can reject the low-band frequency. Also, the matching network in the low-band (high-band) feed includes a bandpass circuit which can help reject the high-band (low-band) frequency. Good isolation between the two hybrid feeds can, hence, be obtained, which makes the antenna with simple structure and small size have good radiation performances in both lower and higher bands. Details of the proposed antenna are presented.
64 citations
Cites background or methods from "Multiband and Small Coplanar Antenn..."
...and shunt capacitor ) [10], [21], [22]....
[...]
...and shunt capacitor ) can lead to significant bandwidth enhancement of the antenna’s lower band [10], [21], [22] and help reject the high-band frequencies, such that the presence of the high-band feed will have small or negligible effects on the low-band performance....
[...]
...The use of bandpass circuit for bandwidth enhancement has been applied in [10], [21], [22]....
[...]
TL;DR: In this paper, a folded loop antenna with multiband operation for ultra-thin smartphone applications is proposed, and the antenna generates four resonant modes, the traditional, higher-order and low-order modes, which cover the GSM850, GSM900, DCS1800, PCS1900, UMTS, TD-SCDMA, LTE2300 and WLAN systems.
Abstract: A folded loop antenna having a very compact size of ${\bf 5} \times {\bf 8} \times {\bf 60}\;{\bf m}{{\bf m}^{\bf 3}}$ with multiband operation for ultra-thin smartphone applications is proposed The antenna generates four resonant modes, the traditional ${\bf 0}{\bf 5}\hbox{-}{{\lambda }}$ , ${\bf 1}\hbox{-}{{\lambda }}$ , and ${\bf 1}{\bf 5}\hbox{-}{{\lambda }}$ resonant modes and an extra higher-order ${\bf 2}\hbox{-}{{\lambda }}$ resonant mode, to cover the GSM850, GSM900, DCS1800, PCS1900, UMTS, TD-SCDMA, LTE2300, and WLAN systems The extra ${\bf 2}\hbox{-}{ {\lambda }}$ resonant mode is generated using a certain distance between the feed point and the shorting point on the ground plane The antenna is studied using simulation and measurement To study the antenna in a more realistic situation, a standard metallic USB connector is placed inside the loop radiator Results show that the USB connector has little effects on the antenna performance
61 citations
Cites background from "Multiband and Small Coplanar Antenn..."
...the metallic rim of the smartphone [9] and using nonresonant planar elements [10]....
[...]
References
More filters
TL;DR: In this article, a theory of characteristic modes for conducting bodies is developed starting from the operator formulation for the current, and the modes are the same ones introduced by Garbacz to diagonalize the scattering matrix of the body.
Abstract: A theory of characteristic modes for conducting bodies is developed starting from the operator formulation for the current. The mode currents form a weighted orthogonal set over the conductor surface, and the mode fields form an orthogonal set over the sphere at infinity. It is shown that the modes are the same ones introduced by Garbacz to diagonalize the scattering matrix of the body. Formulas for the use of these modes in antenna and scatterer problems are given. For electrically small and intermediate size bodies, only a few modes are needed to characterize the electromagnetic behavior of the body.
1,432 citations
"Multiband and Small Coplanar Antenn..." refers methods in this paper
...This resonance has been calculated using characteristic mode analysis, computing the zero crossing of the eigenvalue [28], [29]....
[...]
...1170 MHz being this frequency the resonance of the ground plane computed using characteristic mode analysis [28]....
[...]
Book•
06 Jan 2003
TL;DR: Very low profile monopoles for Internal Mobile Phone Antennas for WLAN applications are discussed in this paper, along with the integration of antennas for different operating Bands and a summary of acronyms.
Abstract: Preface. Introduction and Overview. PIFAs for Internal Mobile Phone Antennas. Very-Low-Profile Monopoles for Internal Mobile Phone Antennas. Base Station Antennas for Cellular Communication Systems. Antennas for WLAN Applications. Dielectric Resonator Antennas for Wireless Communications. Integration of Antennas for Different Operating Bands. Appendix: Summary of Acronyms. Index.
1,021 citations
"Multiband and Small Coplanar Antenn..." refers background in this paper
...2253297 antenna techniques including PIFAs [1], [2], monopoles [3]–[6], loops [7], slots [8], [9], balanced antennas [10], and combinations [11], [12] have been proposed in the literature and industry....
[...]
...Digital Object Identifier 10.1109/TAP.2013.2253297 antenna techniques including PIFAs [1], [2], monopoles [3]–[6], loops [7], slots [8], [9], balanced antennas [10], and combinations [11], [12] have been proposed in the literature and industry....
[...]
...At 900 MHz, the antenna can be easily resonating but not the ground plane unless it has enough length (approximately [1], which results in 133 mm at 900 MHz)....
[...]
TL;DR: In this paper, the authors summarize the work that has been developed by the authors for the last several years, in order to demonstrate that the Theory of Characteristic Modes can be used to perform a systematic design of different types of antennas.
Abstract: The objective of this paper is to summarize the work that has been developed by the authors for the last several years, in order to demonstrate that the Theory of Characteristic Modes can be used to perform a systematic design of different types of antennas. Characteristic modes are real current modes that can be computed numerically for conducting bodies of arbitrary shape. Since characteristic modes form a set of orthogonal functions, they can be used to expand the total current on the surface of the body. However, this paper shows that what makes characteristic modes really attractive for antenna design is the physical insight they bring into the radiating phenomena taking place in the antenna. The resonance frequency of modes, as well as their radiating behavior, can be determined from the information provided by the eigenvalues associated with the characteristic modes. Moreover, by studying the current distribution of modes, an optimum feeding arrangement can be found in order to obtain the desired radiating behavior.
565 citations
"Multiband and Small Coplanar Antenn..." refers methods in this paper
...This resonance has been calculated using characteristic mode analysis, computing the zero crossing of the eigenvalue [28], [29]....
[...]
TL;DR: In this paper, the performance of the mobile phone handset antenna-chassis combination is analyzed based on an approximate decomposition of the waves on the structure into two resonant wavemodes: the antenna-element wavemode and the chassis wavemode.
Abstract: The performance of the mobile phone handset antenna-chassis combination is analyzed based on an approximate decomposition of the waves on the structure into two resonant wavemodes: the antenna-element wavemode and the chassis wavemode. A double resonator equivalent circuit model is presented and used to estimate the impedance bandwidth and the respective distributions of radiation losses with typical parameter values at 900 and 1800 MHz. It is noticed that at 900 MHz, the radiation losses of the antenna element wavemode represent typically less than 10% of the total power. Thus, the antenna element works mainly as a matching element, which couples to the low-Q resonant wavemode of the chassis. At 1800 MHz, the contribution of the antenna element wavemode is larger. By enhancing the coupling and by tuning the chassis resonance, it is possible to obtain an impedance bandwidth of over 50% (6 dB return loss) at both at 900 and 1800 MHz. The results given by the equivalent circuit study are fully supported by those of three-dimensional phone-model simulations, including calculation of the SAR and efficiency values. In prototyping, the 6 dB bandwidth of 5.5% was obtained at 980 MHz with a nonradiating coupling element with a volume of 1.6 cm/sup 3/ on a 120 mm long chassis.
500 citations
"Multiband and Small Coplanar Antenn..." refers background in this paper
...Previous work in the literature [13]–[19], teaches that the resonant frequency of short ground...
[...]
...Since the ground plane plays an important role in the electromagnetic performance of a wireless handheld device, other techniques rely on adding intelligence to it [13]–[21]....
[...]
...The basis for these two experiments is found on the electrical circuit modeling an antenna with a ground plane [13], [19]....
[...]
TL;DR: In this article, the authors proposed broadband impedance matching as a natural way to increase the bandwidth of conventional microstrip patch antennas and found that by using an optimally designed impedance-matching network, the bandwidth can be increased by a factor of at least 3.9, the exact value depending on the degree of matching required.
Abstract: The nature of the inherent narrow bandwidth of conventional microstrip patch antennas is considered. It is observed that, except for single-feed circularly polarized elements, their bandwidth is limited only by the resonant behavior of the input impedance and not by radiation pattern or gain variations, which usually are negligible over a moderate 10 to 20% bandwidth. Therefore, broadband impedance matching is proposed as a natural to increase the bandwidth. The maximum obtainable bandwidth is calculated using Fano's broadband matching theory. It is found that by using an optimally designed impedance-matching network, the bandwidth can be increased by a factor of at least 3.9, the exact value depending on the degree of matching required. A transmission-line prototype for a proper matching network is developed. The translation of this prototype network into a practical structure (e.g. a microstrip or stripline circuit) is considered. Practical design examples and experimental results which clearly show the validity of the technique are given. >
388 citations
"Multiband and Small Coplanar Antenn..." refers methods in this paper
...The inherent bandwidth at a given SWR (standing wave ratio) (S) is estimated using [31]:...
[...]