Byeongkwan Kim

NFC Antenna Design for Low-Permeability Ferromagnetic Material

A novel structure of a near-field communication (NFC) antenna for a mobile handset is proposed by changing the sequence of loop winding and modifying the inner loop structure. In general, the sintered ferrite sheets with higher relative permeability (μr ≈ 200) have been used to reduce the performance deterioration of NFC antennas due to the eddy current in the battery pack of a mobile handset. However, their costs are high, and they are considerably breakable. In this letter, we effectively enhance the performance of an NFC antenna by employing the ferrite-polymer composite with lower relative permeability (μr ≈ 55). The proposed antenna improves up to 23% more reading range and up to 65% better load modulation performance.

Multiband Handset Antenna Analysis Including LTE Band MIMO Service

A compact multiband handset antenna including MIMO antenna operation for LTE 13 band (746 » 787MHz) applications is proposed. The proposed antennas are separately located on the top and bottom portions of a mobile handset in order to use the antenna area more efiectively. The proposed antenna achieves isolations of higher than 14dB, enveloped correlation coe-cients (ECC) of less than 0.25, and total e-ciencies of greater than 40%. The operating frequency bands of Antenna 1 and Antenna 2 include the LTE 13 (746 » 787MHz)/DCS/PCS/UMTS (1710 » 2170MHz) bands and the LTE 13 (746 » 787MHz)/GSM850/900 (824 » 960MHz) bands, respectively.

Closely Mounted Compact Wideband Diversity Antenna for Mobile Phone Applications

Here a compact wideband diversity antenna covering the PCS/UMTS/WiMAX bands with high isolation and low enveloped correlation coefficient (ECC) is proposed. To widen the bandwidth, the proposed antenna uses a structure with a gap-coupled feed and an inductively shorted line that has capacitive compensation between the radiator and the ground plane. Also, a suspended line with a parasitic element is used to enhance the isolation between the two antennas.

Isolation Enhancement of USB Dongle MIMO Antenna in LTE 700 Band Applications

A compact USB dongle multiple-input-multiple-output (MIMO) antenna for Long Term Evolution (LTE) 700 band (704 ~ 746 MHz) applications is proposed. The proposed antenna consists of two symmetrical meander radiators with a capacitively coupled feed. Without the usage of any additional coupling elements between closely mounted antennas, the proposed antenna achieves isolations of higher than 13 dB, enveloped correlation coefficients (ECCs) of less than 0.43, and total efficiencies of higher than 37%.

Enhanced Loop Structure of NFC Antenna for Mobile Handset Applications

A new structure of an NFC loop antenna for mobile handset applications is proposed. The proposed antenna consists of conventional loop elements and a parasitic loop embedded capacitor to enhance its performance. Although the sintered ferrite sheets with higher relative permeability have been used to reduce the performance deterioration due to the eddy current on the battery pack of a mobile handset, their costs are high, and they are considerably breakable. In this paper, with the proposed structure, we effectively enhance the performance of an NFC loop antenna by employing the ferrite-polymer composite with lower relative permeability .

New Configuration of Handset MIMO Antenna for LTE 700 Band Applications

A compact handset multiple-input multiple-output (MIMO) antenna for long-term evolution (LTE) 700 band (746~787 MHz) applications is proposed. The proposed antenna consists of two symmetrical PIFAs. Without the usage of any additional coupling elements between closely mounted antennas, a high isolation (>15 dB) and a low enveloped correlation coefficient () are achieved by the optimum location and arrangement of MIMO antenna elements.

Multiband LTE MIMO antenna for laptop applications

A slim multi-band LTE MIMO antenna covering the LTE12/LTE13/LTE14/LTE17 bands is proposed and designed for laptop applications. Each MIMO antenna mounted on the vertical side edges of a laptop consists of two PIFAs with a single proximity coupled-feed. The radiation efficiency of the proposed antenna is higher than 60% over the entire LTE band. The isolation between two ports is more than 15 dB, and the correlation coefficient is less than 0.2 over the entire operating LTE band.

Multi-band diversity antenna for mobile handset applications

A diversity antenna for a tri-band application is proposed and designed. The proposed diversity antenna consists of two wideband planar inverted-F antennas (PIFAs) and a suspended line between two PIFAs. The measured results show that the proposed antenna has a wide impedance bandwidth (37%) enough to serve a triple band (PCS, UMTS and WiMAX), a high radiation efficiency (> 50%), and a low correlation coefficient (< 0.2).

Ground Plane With Loop Structure for Reducing User's Hand Effect

A half-wavelength loop structure on the ground plane for mobile handset applications is proposed to mitigate the users hand effect on antenna radiation efficiency. The proposed loop structure makes a major portion of electric field distribution on the ground plane shift away from the users hand. This considerably improves the antenna radiation efficiency compared to an antenna without a loop structure under the influence of the users hand.

Diversity and MIMO antenna for multi-band mobile handset applications

A multi-band antenna, which consists of a diversity antenna in the DCS/PCS/UMTS bands and a MIMO antenna in the LTE17/LTE4 bands, is proposed and designed for mobile handset applications. The proposed antenna consists of the meandered PIFAs with branch lines. The radiation efficiency of the proposed antenna is higher than 30% in the LTE17/LTE4 bands and higher than 40% in the DCS/PCS/UMTS bands. The ECC between two identical antennas is less than 0.5 over the entire LTE17/LTE4/DCS/PCS/ UMTS bands.