Antenna and phased array implementations using engineered substrates

Beneficial effects of engineered substrates in design of antennas and phased arrays are demonstrated. Two different applications are considered, one with adaptive electrical and mechanical parameters and the other with properties tailored for special applications such as photonic band gap (PBG) devices. For substrates with adaptive parameters a novel technique for generating inter-element phase shifts in microstrip phased arrays, without the use of phase shifter is introduced. The concept is examined using a circular microstrip patch array. Both cavity model and moment method solution, are used and the possibility of modifying the far field phase by changing the patch or substrate parameters is established. Then, array beam scan by modifying the antenna parameters is demonstrated. For substrates with tailored parameters a perforated dielectric is fabricated. Preferential etching of the substrate is used to generate reduced local dielectric constant in the vicinity of millimeter wave elements. Substrates possessing multiple local or graded dielectric constants are possible.