Simple two‐strip monopole with a parasitic shorted strip for internal eight‐band LTE/WWAN laptop computer antenna

Abstract

mm, L sh ¼ 8.2 mm, was fabricated and tested. The results in Figure 6 show the measurement results are similar to the simulation ones. The first notched band has a frequency deviation and the measured voltage standing wave ratio (VSWR) at higher frequencies are a little higher than the simulated ones. These are probably due to the losses offered by the SMA connector and un-matching among the antenna, SMA connector and vector network analyzer.Simulated surface current distributions at 3.5 and 5.5 GHz are showed in Figure 7 to visualize each notched band. It is observed that the majority of the electric currents are concentrated around the L-shaped slot in the ground plane at 3.5 GHz, and around the eccentric ring and the stub with an arc structure at 5.5 GHz, resulting in a band-notched effect.The measured E-plane and H-plane radiation patterns are shown in Figure 8. It can be seen that the proposed antenna has dipole-like radiation characteristics in E-plane and relatively omnidirectional radiation characteristics in H-plane. CONCLUSIONSA novel compact microstrip-fed antenna with a defected ground structure has been proposed. The simulated and measured results show the designed antenna covers the frequency from 3 to 32 GHz and has the dual band-notched characteristic to reject the interference with the 3.3-3.7 GHz WiMAX band and the 5.15-5.825 GHz WLAN band.ABSTRACT: A dual-wideband internal antenna formed by a simple two-strip monopole (a longer strip and a shorter strip) and a parasitic shorted strip for eight-band long tern evolution/wireless wide area network operation (698-960/1710-2690 MHz) in the laptop computer is presented. The parasitic shorted strip is excited capacitively by the shorter strip of the two-strip monopole and contributes two resonant modes to the antenna, with one in the lower band and one in the upper band, thereby effectively widening the bandwidths of the antenna's two operating bands. Further, the parasitic strip short-circuited to the top shielding metal wall of the display ground in the laptop computer is configured such that its end section with the shorting point is positioned at the side edge of the antenna. This configuration allows the antenna to be placed closely to a nearby grounded plate, with very small effects on the performances of the antenna. This is an advantage for the proposed Figure 8 Measured radiation patterns on (a) E-plane and (b) H-plane for the proposed antenna 706 Figure 12 Measured radiation efficiency and antenna gain of the fabricated antenna. (a) The lower band. (b) The upper band. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com]ABSTRACT: A composite artificial magnetic conductor (AMC) surface is presented for wide band radar cross section (RCS) reduction. The composite surface consists of two kinds of AMC cells with different resonance frequencies. The phase difference between them can be tuned to be within a range close to 6p over a wide bandwidth. Therefore, the reflections from these two different AMC cell...

Planar Monopole Antenna With Two Coupled Strips for Internal Eight-Band Lte/Wwan Laptop Computer Application

“…Detailed size comparison for the proposed antenna with prior designs presented in [1][2][3][4][5][6][7][8][9][10][11][12][13] are also given in Table 1. It is clear that significant size reduction can be achieved with the antenna.…”

“…It has a two-sided structure that is composed of a bent driven strip and two coupled strips. Comparing to those designs [1][2][3][4][5][6][7][8][9][10][11][12][13] used in a portable device, the proposed antenna can achieve not only a multiband property but also a more compact size of 65(L) × 11(W)×0.4(H) mm 3 (0.286 cm 3 ). This will make the proposed antenna suitable for integration within a smaller laptop computer device such as ultrabook.…”

“…To serve more communication systems for a laptop computer device, on the other hand, numerous antenna designs presented in [7][8][9][10][11][12][13] were developed with multiband or wideband features. By properly forming a coupled-fed structure to excite the branch radiator, a monopole antenna [7] and a loop antenna [8] were received high attention due to their eight-band operation characteristics.…”

“…It was also attractive that bandwidth enhancement for a laptop computer LTE/WWAN antenna could be reached using a bent slot [9,10]. Based on a parallel resonant circuit [11] or a parasitic shorted strip [12], two printed monopole antennas may successfully achieve not only eightband LTE/WWAN application but also good radiation performance over the desired bands. For a low-profile laptop computer application, a compact inverted-F antenna working with multiple branch strips to create multiband property has been recently proposed in [13].…”

“…For a low-profile laptop computer application, a compact inverted-F antenna working with multiple branch strips to create multiband property has been recently proposed in [13]. According to those previous studies shown in [1][2][3][4][5][6][7][8][9][10][11][12][13], a smaller size and multiband operation were two critical design challenges for an internal LTE/WWAN antenna in a portable device.…”