Minseok Han

MIMO antenna using a decoupling network for next generation mobile application

A compact MIMO antenna using a decoupling network for next generation mobile application is proposed. The proposed MIMO antenna consists of two parallel folded monopole antennas with the length of 100 mm and spacing S = 6 mm and a decoupling network. In order to improve the isolation characteristic at the LTE band 13, a decoupling network was added between two antennas spaced close to each other. The decoupling network is simple and compact, which contains two transmission lines, a shunt reactive component and quarter-wavelength jointed shorting structure. The proposed MIMO antenna has the isolation of approximately 15 dB at the LTE band 13 and the ECC value less than 0.2 over the whole LTE band.

Multiband MIMO antenna with a band stop filter for high isolation characteristics

In this paper, an internal multiband MIMO antenna with high isolation characteristic for LTE/WCDMA/HSDPA/M-WiMAX applications was proposed. A band stop filter is added at the corner of each radiating elements in order to enhance the isolation characteristic at LTE band. The fabricated antenna has the isolation of about 24 dB at the lower band and higher than 13 dB at the higher band. The measured peak gains of two antenna elements are −7.5 dBi and −6.4 dBi at the LTE band, 3.5 dBi and 2.9 dBi at the WCDMA/HSDPA band and 4.2 dBi and 3.5 dBi at the M-WiMAX band, respectively. The simulated and measured results show that the proposed multiband MIMO antenna could be a good candidate for 4G mobile systems.

Compact multiband MIMO antenna for next generation USB dongle application

A multiple-input multiple-output (MIMO) technique has been considered one of the most promising technologies to enhance the performance of wireless communication systems with high-speed transmission rates. A MIMO system utilizing several antenna components is more advantageous than a single-input single-output (SISO) system in terms of increasing channel capacity and reducing transmitting power [1, 2]. Conventional universal serial bus (USB) dongles [3] are attractive for providing plug-and-play functionality in mobile communication devices such as laptops. Future wireless USB dongles should be capable of accommodating higher data rates than the current systems owing to the advent of various multimedia services. Up to date, most MIMO antenna systems with more than two antennas are three-dimensional rather than planar [4, 5]. In practice, low-profile planar antennas are more preferred so that antenna radiators can be easily integrated with other printed circuit board (PCB) components in USB dongles.

Dual-band MIMO antenna using a symmetric slotted structure for 4G USB dongle application

A compact dual-band MIMO antenna using a symmetric slotted structure is proposed for next generation USB dongle applications. The proposed MIMO antenna consists of two printed dual-band PIFAs with a symmetric slotted strip. The first resonance frequency is controlled by the total length of the main radiating strip with coupling slot (W1 = 2 mm and W2 = 2 mm) has a length of 70 mm, which is about 0.18 wavelengths at 0.77 GHz, but it can easily generate a resonant mode to cover LTE band 13 (LTE Band 13; 0.746–0.787 GHz) and the second one is tuned by the width of the slot (W1 and W2) and the position of the port 1 and 2 (P1 and P2) to cover mobile world interoperability for microwave access band (M-WiMAX Band; 2.5–2.69 GHz). In order to improve the isolation characteristic at the LTE and M-WiMAX bands, a symmetric slotted structure and the jointed shorting line are used to reduce the interaction between the two PIFAs. The proposed MIMO antenna has an isolation of approximately 20 dB at LTE band 13 and the envelope correlation coefficient (ECC) of the two antennas is less than 0.2 over the whole LTE band 13. To evaluate the performance of the proposed antenna, key performance parameters such as the total efficiency, ECC, mean effective gain (MEG), MEG ratio and actual diversity gain are analyzed.

Compact Five Band Internal Antenna for Mobile Phone

A novel five-band planar inverted-F antenna (PIFA) for mobile phones is presented. In this antenna, helical feed, folded patch, and two long slots are employed for compact size and wide bandwidths. Specially, the two slots are effectively used to design low/high resonant frequencies independently. The designed antenna with size of 38 times 12 times 7 mm3 covers DCN (824-894 MHz), GSM (880-960 MHz), DCS (1710-1880 MHz), USPCS (1850-1990 MHz), and WCDMA (1920-2170 MHz) within 3.0:1 voltage standing wave ratio (VSWR). Details of the antenna as well as the measured results are described

Magnetic Resonance-Based Wireless Power Transmission through Concrete Structures

As civil infrastructures continue to deteriorate, the demand for structural health monitoring (SHM) has increased. Despite its outstanding capability for damage identification, many conventional SHM techniques are restricted to huge structures because of their wired system for data and power transmission. Although wireless data transmission using radio-frequency techniques has emerged vis-a-vis wireless sensors in SHM, the power supply issue is still unsolved. Normal batteries cannot support civil infrastructure for no longer than a few decades. In this study, we develop a magnetic resonance-based wireless power transmission system, and its performance is validated in three different mediums: air, unreinforced concrete, and reinforced concrete. The effect of concrete and steel rebars is analyzed.

Dual Polarized Array Antenna for S/X Band Active Phased Array Radar Application

A dual-band dual-polarized microstrip antenna array for an advanced multi-function radio function concept (AMRFC) radar application operating at S and X-bands is proposed. Two stacked planar arrays with three different thin substrates (RT/Duroid 5880 substrates with e r =2.2 and three different thicknesses of 0.253 ㎜, 0.508 ㎜ and 0.762 ㎜) are integrated to provide simultaneous operation at S band (3～3.3 ㎓) and X band (9～11 ㎓). To allow similar scan ranges for both bands, the S-band elements are selected as perforated patches to enable the placement of the X-band elements within them. Square patches are used as the radiating elements for the X-band. Good agreement exists between the simulated and the measured results. The measured impedance bandwidth (VSWR≤2) of the prototype array reaches 9.5 % and 25 % for the S- and X-bands, respectively. The measured isolation between the two orthogonal polarizations for both bands is better than 15 ㏈. The measured cross-polarization level is ≤?21 ㏈ for the S-band and ≤?20 ㏈ for the X-band.

MUltiple Antenna System for mobile handset applications

A multiple antenna system for mobile handset application is proposed. The proposed multiple antenna system consists of planar inverted-F antenna (PIFA) for mobile operation and a shorted monopole MIMO antenna with a decoupling network for WLAN operation. By adding a λ/4 open stub to PIFA, an additional resonance at 2 GHz band was generated and consequently the impedance matching characteristic was improved. In order to improve the isolation characteristic between the PIFA and MIMO antenna elements, each element is placed at the corner of each edge of the system ground. In addition, decoupling network was added at the feeding line of a shorted monopole antenna element. The proposed WLAN MIMO antenna has the isolations of about 15 dB at 2 GHz and 5.8 GHz bands while that at 5.2 GHz band is over 18 dB. It is observed that the antenna can cover GSM/DCS/PCS/UMTS and 2.4/5.2/5.8 GHz WLAN service, simultaneously.)

Dual-Band MIMO Antenna Using a Band Stop Matching Circuit for USB Dongle Applications

In this paper, a dual-band MIMO antenna with a band stop matching circuit for next generation USB dongle application is proposed. The proposed multiband MIMO antenna consists of two dual-band PIFAs which provide wideband characteristics. In order to improve the isolation characteristic at the LTE(Long Term Evolution) band, a band stop matching circuit was inserted at the corner of each antenna element. The inserted band stop matching circuit is to suppress the surface current at the specific frequency band and to generate two additional resonances around 770 MHz for LTE band and near 830 MHz for digital communications network(DCN) service. The proposed MIMO antenna can cover LTE and DCN services, simultaneously.

Multiband MIMO antenna using a symmetric slotted structure for next generation USB dongle application

A compact multiband MIMO antenna using a symmetric slotted structure is proposed for next generation USB dongle applications. The proposed MIMO antenna consists of two triple-band PIFAs with a symmetric slotted structure. The first resonance frequency is controlled by the total length of the main radiating strip with coupling slits (slit 1 and slit 2), which has a length of 70 mm (about 0.18 wavelengths at 0.77 GHz). The second one can be obtained by inserting on additional slit (slit 3) for WCDMA band. Moreover, the third resonance frequency can be tuned by the width of coupling slits (slit 1 and slit 2) and the position of the port 1 and 2 (P1 and P2) to cover M-WiMAX Band (2.5–2.69 GHz). To obtain a high isolation characteristic between two antennas, a symmetric slotted structure and the jointed shorting line are used to reduce the interaction between the two PIFAs. The proposed MIMO antenna has an isolation of approximately 15 dB and the envelope correlation coefficient (ECC) of the two antennas is less than 0.2 over the whole wanted frequency bands.