Passive components, such as microstrip power couplers, operating in microwave spectrum-regime can be considered as absolute energy eaters because they reduce the overall system throughput. The compatible 3-D volumetric design related issues resulting into undesired qualitative energy and power losses are of major concern for designers. Naturally available conventional double positive dielectric (DPS) materials such as FR-4, PTFE, and Teflon have been popularly used as substrates on the cost of deteriorating the overall electrical performance of transceiver systems. These DPS materials have both the dielectric permittivity (ε) and magnetic permeability (µ) positive. The recent RF and wireless communication industry demands the symmetric and asymmetric microstrip forward and backward impedance couplers designed on the principle of novel left-handed electromagnetic materials. These metamaterials observe unique electromagnetic properties of having the ε and/or µ less than zero simultaneously that replace those having been designed using DPS. This paper discusses and investigates the novel concept for the methodological improvements to various measurable parameters like S-parameters, coupling _bandwidth and _ratio, multi frequency response, and volumetric miniaturization for these couplers. It can be achieved through the introduction of Split Ring Resonator (SRR) and rod structure in thin slab of naturally available DPS substrate. Mechanical design issues such as 2-D alignment and orientation, dimensions, spacing between SRRs and rods, number and size of unit cells, and structural-materialistic properties deciding the electrical characteristics of the metamaterial and the coupler responses are focused. Mathematical justifications and logical concepts through numerical modeling carried out by various researchers have been highlighted and studied here.
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