A wideband loop‐type antenna

Abstract

A new feed structure with a loop-type radiator is proposed for achieving a wide bandwidth characteristic. The method for achieving a wide impedance bandwidth characteristic is to control the input impedance of the feed structure using a parallel capacitor and inductor. The size of the ground plane is 50 3 20 mm 2 , which is usually used as the ground for USB dongle applications. The size of the rectangular ground clearance for the loop-type antenna is 8 3 4 mm 2 . The proposed antenna was designed and measured using HFSS and a 3D CTIA OTA chamber. The center frequency is 2.45 GHz and the impedance bandwidth under VSWR 5 2:1 is 550 MHz (2.18-2.73 GHz), which is adequate for long term evolution bands (7, 30, 40) and Wi-Fi applications.

Miniaturized dual‐band loop‐type ground radiation antenna with enhanced bandwidth for mobile devices

“…Figure A shows the impedance variation in the low band depending on the ratio of L F and C FL . As C FL increases and L F decreases, the locus of the feeding loop resonance becomes smaller . Figure B shows the impedance variation of the high band according to C FH and the length d .…”

“…As C FL increases and L F decreases, the locus of the feeding loop resonance becomes smaller. 7 Figure 2B shows the impedance variation of the high band according to C FH and the length d. Because The simulated reflection coefficients of the proposed antenna with the selected values and reference antennas are shown in Figure 3. The reference antenna (ANT.…”

“…The miniaturization of the antenna inevitably leads to a decrease in antenna performance . As an efficient and effective solution for the miniaturization of mobile antennas, previous studies have presented various loop‐type ground radiation antennas that couple with the characteristic modes of the printed circuit board (PCB) for far‐field radiation in order to achieve ultra‐miniaturization and high performance . Unfortunately, the impedance bandwidth provided by ground radiation antennas is narrow, which restricts their applications in modern terminal devices with broad bandwidth coverage that has arisen from the desperate demand of the expanding frequency spectrum for current and future mobile communications.…”

“…[1][2][3] As an efficient and effective solution for the miniaturization of mobile antennas, previous studies have presented various loop-type ground radiation antennas that couple with the characteristic modes of the printed circuit board (PCB) for far-field radiation in order to achieve ultra-miniaturization and high performance. [4][5][6][7] Unfortunately, the impedance bandwidth provided by ground radiation antennas is narrow, which restricts their applications in modern terminal devices with broad bandwidth coverage that has arisen from the desperate demand of the expanding frequency spectrum for current and future mobile communications. Accordingly, bandwidth enhancement techniques for single frequency bands have been studied in ground radiation antennas by adding an inductor in series or parallel into the loop feed in order to control the impedance characteristics of the feed structure 6,7 ; however, a ground radiation antenna that enhances the bandwidths in multiple frequency bands has not been reported yet.…”

A wideband loop‐type ground radiation antenna using ground mode tuning and optimum impedance level

“…Various techniques of bandwidth and radiation enhancement of the GradAint had been proposed in the literature. Optimum impedance level of the feeding loop had been utilized to achieve wider impedance bandwidth using a series and a parallel combination of inductor and capacitor. The impedance level of radiation loop can also be used for bandwidth enhancement .…”