Novel approach in design of miniaturized passive microwave circuit components using metamaterials

Abstract

A novel two‐step algorithm to accurately analyze the transmission properties of the transmission lines loaded with electrically small resonators is introduced. The algorithm comprises a set of equations to predict and modify the geometrical parameters of the transmission line when loaded with the electrically small resonators. To verify the algorithm, a comparative study on the performance of a proof of concept compact metamaterial hybrid branch‐line coupler through numerical analysis and laboratory measurement was presented. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:1341–1347, 2017

Compact Branch-Line Coupler With Harmonic Suppression Based on a Planar Simplified Dual Composite Right/Left-Handed Transmission Line Structure

“…Reactive area Harmonic suppression [4] Distributed Capacitors 38% Not shown [5] Asymmetrical T-Structures 12.2% Not shown [6] H-shaped transmission lines 36% Yes [7] Interdigitated shunt capacitors 26.8% Yes [9] CSRRs 40% Not shown [11] Symmetric polygonal folding lines 24% Not shown [12] Coupled lines 33% Not shown This work planar SD-CRLH TLs 26% Yes Figure 9. Phase difference and amplitude balance between S 21 and S 31 of the proposed branch-line coupler.…”

“…However, the conventional branch-line coupler will occupy large area especially at interest low frequency band. Therefore, various techniques have been proposed to miniaturize the size of the branch-line coupler [2][3][4][5][6][7][8][9][10][11][12]. In [2], the size of the coupler can be reduced significantly using lumped elements, but the lumped elements with precise value and high quality are not always available.…”

“…Most of them are realized by different forms of shunt loading, such as low or high impedance lines [3][4][5][6], interdigitated capacitor [7]. Other approaches using defected ground structures (DGS) [8,9], fractal geometries [10,11], coupled lines [12] are also introduced to effectively reduce the area. However, in some cases, the electrical performance deteriorates compared to the conventional one.…”