One varactor-tunable High Impedance Surface (HIS) is proposed and used in design of an active metamaterial absorber. The proposed HIS structure is based on mushroom-type HIS, in which varactors are introduced to adjust the effective capacitance and tune the resonance frequency. The primary ground plane is etched as the bias network for these loaded varactors, and another ultra-thin grounded she...

This paper proposes a novel design for a compact, high-isolation WCDMA indoor repeater antenna. The proposed antenna consists of a patch antenna and metamaterial absorber. The required WCDMA bandwidth is obtained by utilizing the coupling between the main and the parasitic patches. In addition, high isolation is achieved using the metamaterial absorber, which has an absorption of about 98% at 2...

We present a metamaterial absorber detector array that enables room-temperature, narrow-band detection of gigahertz (GHz) radiation in the S band (2-4 GHz). The system is implemented in a commercial printed circuit board process and we characterize the detector sensitivity and angular dependence. A modified metamaterial absorber geometry allows for each unit cell to act as an isolated detector ...

This paper reviews recent work in the area of active metamaterials where transistors and circuitry are embedded within metamaterial structures for novel functions. In one function, embedding of psuedomorphic high electron mobility transistor (pHEMT) within the metamaterial resonator allows realization of a terahertz modulator. A variation of this approach utilizes diodes to modulate the metamat...

The design, simulation, fabrication, and measurement of two structures of metamaterial absorbers (MA) is investigated at microwave frequency in this paper. By stacking of one layer structure on the top of each other, a two-layered structure is generated. The unit cell at each layer consisting of two sets of various circular and square patches are designed so that the structure exhibit quad band...

Abstract Ultrathin and broadband metamaterial absorber with loaded four lumped resistors is proposed analyzed. The reported design based on increasing the absorptivity by reducing reflection transmission coefficients simultaneously. Therefore, continuous metallic ground used to achieve zero while reduced matching impedance of free space (Z = Z 0 or μ r ε ). Additionally, electric magnetic reson...

We present the design, numerical simulations and experimental measurements of terahertz metamaterial absorbers with a broad and flat absorption top over a wide incidence angle range for either transverse electric or transverse magnetic polarization depending on the incident direction. The metamaterial absorber unit cell consists of two sets of structures resonating at different but close freque...