Antennas and Antenna Arrays

UWB Antennas

The ultra-short pulse input of UWB antennas can be synthesized from the desired output. Thus the energy can be directed to any desired spatial position by using the synthesized input for that specific output. Two interesting major areas of study are the analysis of the output waveform for a specified input and the synthesis of the driving-point voltage for a specified output. Both analysis and synthesis can be achieved from a single set of simulated results if one applies the reciprocity relation for antennas.

Metamaterials for Antennas

Metasurfaces such as EBG/AMC, Epsilon and Mu near zero (EMNZ) and frequency selective surfaces combined with planar and patch antennas are investigated for communication systems. The metasurfaces may be applied either as substrate or superstrate to the antenna to increase its radiation performance while maintaining a low profile.

Conformal Antennas

Conformal antennas are ideal for dynamic applications due to the reduction of aerodynamic drag effects. These antennas are popularly mounted on surfaces of aircraft, satellites, and vehicles, etc. Conformal array shows wide coverage ranges as compared to planar arrays. Array mathematical principles have to be used for synthesis of conformal arrays.

Antenna Array Synthesis

Antenna array pattern synthesis is achieved either by static synthesis or by dynamic synthesis. Systems with dynamically synthesized arrays provide improved signal quality, but are typically more expensive. As the feasible range of solutions is extremely large, an exhaustive search algorithm is required to identify an optimal solution from among the large pool of possible solutions. This can be achieved through non-convex and non-linear optimization.