Anti-DBI (aa 1-104) polyclonal antibody

A composite right/left handed (CRLH) metamaterial antenna is proposed in this paper. The antenna is designed for WLAN IEEE 802.11 standard; where bands 2.4 GHz usage frequency 2401-2495 MHz and 5 GHz usage frequency 5170-5875 MHz worldwide. A composite right left handed metamaterial has combined effect of right handed and left handed metamaterial and which creates dual band resonance in the antenna. By providing shorting pin loading at edge of the radiating metal, the left handed metamaterial property is created in the antenna. The antenna occupies rectangular area of 38.2 x 29.1 mm(2) and 6 mm air gap from ground plane. The return loss of -10 dB is achieved over the bandwidth with promising peak gain of 2.3 dBi and 8.6 dBi for 2.4 GHz and 5 GHz band, respectively. The antenna is fabricated, and measured values are closely matching with simulation results. The proposed antenna has orthogonal radiation patterns and maximum efficiency of 84.2% and 90.3% for dual frequencies.

An ultra-high frequency (UHF) travelling wave antenna based on complementary split ring resonator (CSRR) element is investigated in this study for pure near-field radio frequency identification (RFID) system. The proposed antenna consists of a T-type power divider, 180 degrees phase shifter, two microstrip transmission lines ended with two 50 Omega resistors and the metal ground loaded CSRR elements. The CSRR elements are loaded on the metal floor corresponding to the minimum current points and middle of the two transmission lines. The CSRR elements resonate at the centre frequency and introduce coupling to enhance the magnetic field. The measured - 10 dB impedance bandwidth of the proposed antenna is 46 MHz (889-935 MHz), which covers the standards of Chinese and American bands. The reading regions for near-field tag, far-field tag and anti-metal tag are 400 x 200 x 10mm(3), 400 x 200 x 70mm(3) and 400 x 200 x 60mm(3), respectively. The far-field gain is less than - 22 dBi, which makes the antenna suitable for the pure near-field application.