Wideband miniature G-shaped antenna for dual-band WLAN applications

Abstract

A dual band dipole antenna with branch lines for WLAN dual band and phase reversal operation was proposed and investigated. For the dual band and phase reversal operation, the folded branch lines were analyzed in the current distribution. The electrical length and radiation patterns at the harmonic resonance frequency are influenced by the length of the folded branch lines. The proposed antenna has dimensions of 45.16 Â 9 Â 0.6 mm 3 . The obtained impedance bandwidths (defined by 2:1 VSWR) were 313 MHz (2.29-2.603 GHz) and 371 MHz (5.639-6.01 GHz). The measured maximum gain was 2.96 and 4.47 dBi at each operating band, respectively. ABSTRACT: A new fiber-optic liquid-level sensor (LLS) for continuous monitoring of the liquid level is proposed using a fiber-optic displacement sensor (FODS). A float is used to measure the level of liquid in the tank and it is connected to the FODS probe to convert the variation of the liquid level into a displacement change. The performance of the LLS is investigated for two different FODSs with a concave and a flat mirror target. With a concave mirror, six measurement slopes within a range of 25 mm are observed with the highest sensitivity of 1.3015 mV/mm. With a flat mirror, two measurement slopes are observed with the highest sensitivity of 1.4533 mV/mm and the longest measurement range of 4.8 mm.

An Ultra-Compact Dual-Band Antenna With Tuning Arms for Wlan Applications

“…The dimension of the proposed antenna is only 9×24 mm 2 , much smaller than those reported antennas (The least size in [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] is 30 × 25 mm 2 ). Connective and concentric double split rings (CCDSR) are used as radiating element to generate two WLAN frequency bands and prolong current path for compactness.…”

“…Microstrip-fed and coplanar waveguide (CPW)-fed monopole antennas have been reported [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Some special techniques have been used to generate dual-band characteristic, such as tapered bent folded patch [2], fork-like monopole [3], patch with shaped slots [4,5], double-T antenna [6], parasitic strips antenna [7], varactor diodes [8], cutting slots on the patch [9], tuning stub [10], PIFA antenna [11], cross-slot antenna [12], and some antennas which use two or three radiant patches to satisfy 2.4 GHz band, 5.2/5.8 GHz band [13,14].…”

“…Some special techniques have been used to generate dual-band characteristic, such as tapered bent folded patch [2], fork-like monopole [3], patch with shaped slots [4,5], double-T antenna [6], parasitic strips antenna [7], varactor diodes [8], cutting slots on the patch [9], tuning stub [10], PIFA antenna [11], cross-slot antenna [12], and some antennas which use two or three radiant patches to satisfy 2.4 GHz band, 5.2/5.8 GHz band [13,14]. Miniaturization of antenna is especially attractive in integrate circuit.…”

Compact CPW-Fed Tri-Band Antenna for Wlan/Wimax Applications

“…Thus, several dual-band antennas [1][2][3] and tri-band antennas [4][5][6][7][8][9][10][11][12][13] have been proposed to cover the bands for WLAN or WiMAX applications. The modified planar monopole pattern is constantly adopted to realize dual-band operation because of its easy fulfilment, such as the folded open ended stub monopole [1], T-shaped monopole [2], triangular monopole and U-shaped monopole [3]. Although these antennas have the advantage of simple structure, only two bands are included, which leads to low working modes in the communication terminal systems.…”

A Compact CPW-Fed Monopole Antenna With a U-Shaped Strip and a Pair of L-Slits Ground for Wlan and Wimax Applications

“…And in [9] the three sections impedance transform-line takes up large volume. In [10,11], there is a limit in obtaining omni-directional radiation characteristics, especially at the higher band.…”