Modified printed monopole antenna with well-matched impedance bandwidth for through the wall microwave imaging applications

In this study, a printed monopole antenna with well-matched impedance bandwidth, reasonable gain and omnidirectional radiation pattern for through the wall imaging (TWI) applications is proposed. This work can be divided into two parts. The antenna design process which is the first part of this study can be explained with three design stages: antenna design is initiated with a base printed monopole antenna; parasitic patch elements are applied to the base antenna in order to obtain suitable frequency region below -10 dB and -20 dB in terms of reflection coefficient parameter; finally, the antenna is modified with the slotted ground to have better impedance match below -20 dB. Lastly, the antenna design with optimized parameters is used in a TWI scenario which is the second part of this paper. The scattering parameters are measured in two sequential time steps, and the difference in these two data is used as the data of the inversion scheme for TWI scenario. The imaging process is performed via the linear sampling method and the factorization method. The numerical simulations with a realistic wall model demonstrate that the antenna is capable of detecting objects behind the wall.