Multisection vialess microstrip‐line balun with backside aperture and floating patches

Investigation of a compact and broadband balun

“…To date, various balun structures have been investigated for applications in microwave integrated circuits (MIC) and microwave monolithic integrated circuits (MMIC) . Generally, these balun topologies are based on the following types: the first one is the Marchand baluns [1][2][3][4] or coupled line baluns [5][6][7]; the second one is the slotline-based baluns [8 -11]; the third group is the power divider-based ones [12][13][14][15][16]; and the last one is branch-line baluns [17,18]. They are extensively implemented in planar versions [2-5, 7, 9, 12, 13, 15-18], multiplayer structures [6,8,10,11,14,19], or LTCC [20] as well as 3D configurations [21,22].…”

A Compact and Broadband Balun Design for Lte Applications

“…This will help to preserve balanced radiation patterns [4,5].To meet the requirements of most contemporary wireless communication, size reduction and bandwidth enhancement are considered as the most challenging task that balun designers are facing. In particular, special attention is given to balun designs which can be integrated on the same substrate with compact antennas for use in mobile/portable applications.Numerous syntheses of balun structures have emerged and been presented for wideband applications with the aim of supporting the developing broadband technologies [6][7][8][9][10][11][12][13][14][15][16][17][18]. The most popular types of wideband baluns include the planar marchand baluns [6,7], broadband balun based on composite right/left-handed transmission line [8,9], three-line balun with wide bandwidths using exact synthesis designed as in [10], balun with multi-sections coupled-lines demonstrated in [11], a CPW balun using a multistage Wilkinson power divider for bandwidth improvement purpose [12], and the wideband balun design utilizing Wilkinson divider followed by Lange couplers for phase shifting was investigated in [13].…”

“…A branch line balun having meandered branches and printed on a high resistive silicon substrate to achieve tight coupling was proposed in [23]. Table 1 summarizes the performances of all the aforementioned wideband baluns [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] in terms of operating frequency band, impedance bandwidth, size (where λ o is the lowest operating frequency), S 21 /S 31 values, employed technologies/techniques and complexity. By examining all the aforementioned wideband baluns, it was found that the proposed balun has the advantage of accomplishing a broader frequency range than published works [6][7][8][9][10][11][12][14][15][16][17][18][19][20][21][22][23].…”

“…In contrast to [11,16,[19][20][21]23], this article proposes a printed wideband balun that accomplishes both a size reduction and the potential to simultaneously cover the whole frequency band of LTE from 700 MHz to 2600 MHz. In terms of complexity, it can be noted that the proposed balun has come up with less complexity than the works in [8,[10][11][12][13][14]15].…”

“…In contrast to [11,16,[19][20][21]23], this article proposes a printed wideband balun that accomplishes both a size reduction and the potential to simultaneously cover the whole frequency band of LTE from 700 MHz to 2600 MHz. In terms of complexity, it can be noted that the proposed balun has come up with less complexity than the works in [8,[10][11][12][13][14]15]. Moreover, this proposed balun was printed on a low permittivity substrate compared to works in [11,23], which makes the proposed balun a good candidate to be printed exactly underneath the ground plane of the authors' balanced antenna in [24] which in turn may not affect the whole system performance.…”