23:1 Bandwidth ratio quasi‐lumped component balun on a multilayer organic substrate

Abstract

Abstract:In this paper, we present the design and development of a novel ultra-wideband coupled line balun on a multilayer Liquid Crystal Polymer (LCP) substrate. The balun is designed using a quarter wavelength (λ/4) asymmetric broadside coupled line. The defected ground structure (DGS) and a lumped phase compensation circuit are developed to achieve wide bandwidth performance for the balun. The balun has a measured bandwidth ratio of 23:1, from 80 MHz to 1860 MHz. Within the operating bandwidth, the experimental results demonstrate that the balun achieves an input return loss of better than 10 dB, an insertion loss of better than 1 dB, an amplitude imbalance of better than ±0.4 dB and a phase imbalance of better than ±10 degrees. The size of the balun is 40.64 mm x 40.64 mm or 0.22 λg x 0.22 λg, where λg is the guided-wavelength at the center frequency of 970 MHz.

Novel stacked‐defected ground structures for ultra‐wideband low loss balun designs

“…Various modifications and enhancements have been reported for different purposes. Among these are techniques for balun miniaturization, balun bandwidth improvement, and compensated imbalances with lumped element . Most balun designs have a trade‐off among bandwidth, insertion loss, total size, and imbalances compensation.…”

“… utilizes a series inductor for the compensation with a bandwidth ratio of 2:1 only. Recently, defected ground structures (DGS) was implemented as single ground shape or double ground shapes to achieve a wideband baluns but asymmetrical shapes of DGS causes bad imbalances.…”

“…Among these are techniques for balun miniaturization, 3 balun bandwidth improvement, 4,5 and compensated imbalances with lumped element. [6][7][8] Most balun designs [3][4][5][6][7][8] have a trade-off among bandwidth, insertion loss, total size, and imbalances compensation. For instance, Ref.…”

Gallium arsenide 0.5–18 GHz antenna front‐end with integrated limiter and differential to single ended low‐noise amplifier

“…Actually, a large number of broadband amplifiers with a non-zero common-mode amplification has been reported in the literatures [1][2][3][4][5] and they require an additional balun to drive differential mode antennas. Many solutions have been already proposed in the literatures [6][7][8][9][10][11][12][13][14][15][16][17][18][19], both as passive or active architectures, but all of them experiment some drawbacks for the considered application. Typically, a balun composed of passive components has a large size (in the order of several square centimetres), and usually has a relatively narrow bandwidth.…”

Design of 600-W Low-Loss Ultra-Wideband Ferriteless Balun

“…Coupled-wire baluns are formed by winding a coaxial cable in N turns to enhance inductance by a factor N 2 , resulting in a very large balun structure [19], [20]. Recently, to realize a compact size and broadband performance, multilayered planar baluns employing defected ground structures have been proposed but only operated at low power levels [6], [9]. While the multilayered baluns in [6]- [10] achieve broadband and low-loss performance, they are not suitable for high power applications because those balun topologies use broadside coupled transmission lines.…”