Isolation Enhancement in Microstrip Antenna Arrays 
Slotted Meander-Line Resonator (SMLR) is implemented by creating defect in the microstrip structure. This resonator is designed to block the surface current at the resonant frequency of the two patch antennas coupled along H-plane operating at 3.6 GHz. The proposed configuration provides an improvement in isolation by 10 dB (measured value) with a reduced edge-to-edge spacing of 7 mm (λ0/9). This resonator has been designed, simulated, and validated experimentally. KeywordsAntenna array, isolation enhancement, meander lines, mutual coupling reduction, resonators.
New EBG solutions for mutual coupling reduction
Electromagnetic Band Gap (EBG) based on Frequency Selective Surfaces (FSS) [1] are one type of metamaterials [2] with electrical properties [3]. This EBG are used in mutual coupling reduction, back lobe radiation reduction, etc. In this work not only new shapes for the mushroom-type are presented, but also multilayered configurations were studied in order to reduce the patch size and the necessary number of elements.
Dual band planar soft surfaces
The design of dual band planar soft surfaces is presented here. Based on previous works, the parameters of a particular planar realisation of soft surfaces are used to create two frequency bands in which surface waves are suppressed. The planar soft surface is made with strips printed over a grounded dielectric slab with grounded vias. The parameters of the soft surface such as the strip width, the period of the vias and the position of such vias across the strip determine the frequency band at which the structure has a bandgap. It is demonstrated that by interleaving two planar soft surfaces with some different parameters over each other, the stopband of each one of them is maintained, and consequently, a dual band operation is obtained. Any of the mentioned parameters can be employed to this aim as shown in this work. The conclusions are supported by experimental results. The agreement between the measurements and the simulation results is good enough to demonstrate the dual band effect.