Development of a compact ICRF antenna for high-power and long-pulse plasma heating in the KSTAR

For the high-power and long-pulse ion cyclotron range of frequencies (ICRF) heating of the KSTAR plasma, we developed the compact ICRF antenna (CIA). The target injection power of CIA is 2 MW for 300 s. In order to continue injecting the power into plasma even if drastic instantaneous changes occur in the plasma condition, such as ELM events, we adopted the internal conjugate-T method for the load resilience. Between antenna heads and the junction point, impedance transformers were inserted to satisfy the condition of conjugate-T in a limited space keeping the electric field on the transformer low enough. To reduce the risk of water leakage into the vacuum chamber, only the backsides of antenna heads are water-cooled in the in-vessel region

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

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

A Compact Frequency Reconfigurable Antenna for LTE Mobile Handset Applications

A compact (8 × 62 × 5 mm3; 2.48 cc) frequency reconfigurable antenna that uses electrical switching with PIN diodes is proposed for the low frequency LTE band (699 MHz–862 MHz), high frequency LTE band (2496 MHz–2690 MHz), GSM850/900 bands (824 MHz–960 MHz), and DCS/PCS/WCDMA bands (1710 MHz–2170 MHz). The penta-band PIFA is first designed for GSM850/900/DCS/PCS/WCDMA bands by using two slits and ground pins within a limited antenna volume (8 × 54.6 × 5 mm3; 2.18 cc). The frequency reconfigurable antenna based on this penta-band PIFA is thus proposed to additionally cover all LTE bands. The proposed antenna has two PIN diodes with an optimal location. For State 1 (PIN diode 1: ON state, PIN diode 2: OFF state), the proposed antenna covers the low frequency LTE band, DCS/PCS/WCDMA bands, and high frequency LTE band. For State 2 (PIN diode 1: OFF state, PIN diode 2: ON state), the antenna covers the GSM850/900 bands. Simulated and measured results show that the total efficiency of the proposed antenna was greater than 40% for all operating frequency bands

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 (ECC<0.35) are achieved by the optimum location and arrangement of MIMO antenna elements

Diversity and MIMO antenna for multi-band mobile handset applications

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