A Compact Microstrip Quadruplexer Using Slotline Stepped Impedance Stub Loaded Resonators

Abstract

Abstract-In this paper, a novel compact quadruplexer is implemented by using slotline stepped impedance stub loaded resonators (SISLRs) in ground plane. Four folded dual-mode slotline SISLRs with one input and four output coupled line structures are designed at different frequencies for the quadruplexer operation. By properly adjusting the geometrical parameters of a single dual-mode slotline SISLR, its first two resonant frequencies can be controlled, and thus it can be utilized to implement a second-order bandpass filter when these resonant frequencies are suitably assigned. Furthermore, because the proposed quadruplexer utilizes the distributed coupling technique, a small circuit size can be obtained. As a result, the proposed quadruplexer occupies an extremely small area, i.e., 0.22λ 0 ×0.25λ 0 (0.36λ g ×0.41λ g ). Finally, good agreement between measurement and EM simulation verifies the design method successfully.

Power Divider Based on Stepped-Impedance Slotline

“…SIS has been studied and utilized in some designs, such as the resonators in [22,23,25] and the diplexers in [24]. However, study about applying SIS on power divider has not been done up to now.…”

“…Stepped-impedance slotline (SIS) [22][23][24][25] and one lumped resistor are introduced to improve the isolation between out-of-phase output ports. Simulated and measured results, which exhibit a good agreement, show that the proposed power divider has good return loss, high isolation, excellent phase balance, as well as flat group delay over the band 5 GHz-10 GHz.…”

Novel microstrip quadruplexer with wide stopband for WiMAX applications

“…High‐performance microstrip diplexers, triplexers, and quadruplexers are widely demanded by multiservice communication systems to send and receive signals. Various types of microstrip diplexers, triplexers, and quadruplexers are reported recently. Coupled open loops in Refs.…”

Miniature Triple-Mode Diplexer With Good Selectivity

“…In turn, higher order mode of the filters is required to provide sharp passband skirts; however, this will lead to the whole larger dimension. In [8,9], the defected ground structures are utilized to design diplexers. Conversely, this method is not appropriate since they always have top and bottom circuits, which is an inflexible and complicated circuit.…”

“…The most common approach to realize a diplexer is using two bandpass filters with parallel/cross coupling of single-mode resonators. The notable resonators are open loop resonators, hairpin line resonators, stepped impedance resonators, quarter-wavelength resonators, and hybrid resonators respectively [4][5][6][7][8][9]. Using such resonators, each of the passbands is designed at its fundamental frequency.…”