Wideband compact Vivaldi Antenna loaded with dielectric lens for millimeter-wave applications

Wideband Antipodal Vivaldi Antenna (AVA) loaded with dielectric lens for fifth generation gigabit communication and millimeter-wave (MMW) imaging system is presented. The simulated results demonstrated that proposed antenna can be operated from 10 GHz up to 65 GHz band showing 146% fractional bandwidth. The designed antenna is considered for transmission of short time duration pulses covering 27-33 GHz frequency band. We examined time domain performance of our proposed AVA for an ultra-short 16 ps fifth derivative Gaussian pulse excitation. We found up to 11% improvement in pulse radiation efficiency for the 5^th derivative Gaussian pulse excitation compared to conventional 1^st order Gaussian. Moreover, gain improvement is up to 7 dB by loading half spherical dielectric lens over AVA. Further analysis is done by calculation of energy pattern and pulse fidelity factor (PFF) for both kinds of pulse excitations. Within 3-dB beamwidth of the proposed antenna PFF value is found more than 90%. The AVA with lens reduces the 3 dB energy beamwidth from ±18° to ±8° owning side lobe levels less than -20 dB. The proposed antenna is compact in size with physical dimension of 31×38 mm².