Shraman Gupta

Gain Enhancement of Circularly Polarized Dielectric Resonator Antenna Based on FSS Superstrate for MMW Applications

In this communication, a high gain circularly polarized (CP) dielectric resonator antenna (DRA) is proposed. The radiating DR is coupled to a 50 Ω microstrip line through an X-shaped slot etched off the common ground plane. Using a frequency selective surface superstrate layer, a gain enhancement of 8.5 dB is achieved. A detailed theoretical analysis is given and used to optimize the superstrate size and the air gap height between the antenna and superstrate layer. The proposed DRA is designed, simulated, implemented, and tested. The high gain CP DRA has the potential to be used for millimeter wave wireless communication and imaging systems.

SIW beamforming of 2 × 2 and 4 × 4 AFLTSA arrays for MMW applications

In this paper, a beamforming technique using multimode section based on s-parameters has been analyzed for antipodal fermi-linear tapered slot antenna (AFLTSA). The analysis is proposed for 2 × 2 and 4 × 4 sub arrays on Rogers 5880 substrate with a relative dielectric permittivity εr=2.2 in order to achieve an objective of high gain and narrow beamwidth, which can be used for target tracking and precise detection applications. The solution frequency is chosen as 32.5 GHz which yields 3 dB beamwidth of ~ 20° and ~13° for 2 × 2 and 4 × 4 AFLTSA structures respectively. The realized gain achieved for these two structures is 12.39 dB and 14.19 dB respectively. The simulation results for multimode section and sub array antenna structures are presented using Ansoft HFSS simulation tool.

Metamaterial-corrugated fermi tapered slot antenna for MMW applications

A novel approach is presented to increase the realized gain for millimeter wave applications at 28 GHz using metamaterial (MTM) profile based antennas. The concept of epsilon-negative medium (ENG) and double negative medium (DNG) is analyzed to have metamaterial corrugations instead of sine corrugations. In this paper, the antipodal Fermi based tapered slot antenna (AFTSA) is analyzed using metamaterial corrugations which allow a total gain greater than 14 dB in the H-plane for a frequency range of 24–30 GHz. The extraction of effective parameters of a metamaterial unit cell is also presented depicting its ENG and DNG behavior. The antenna is also analyzed using the practical model of a 2.92 mm connector, thereby showing the effect of end launch connectors on the millimeter wave frequency range.

Sequential feeding networks for subarrays of circularly polarized patch antenna

The following paper presents and compares simulated results of reflection coefficient, axial ratio, and realized gain, which are related to various structures of patch antenna including single element, subarrays of 2×2 and 4×4. The proposed antennas have a capability of circular polarization in millimeter wave applications. In addition, the basic structure of antennas is in the form of aperture coupled conducting patch. In order to extend CP bandwidth, parallel sequential feeding technique is used in subarrays 2×2 and 4×4.

High gain antipodal fermi-linear tapered slot antenna (AFLTSA) array fed by SIW for MMW applications

A 32.5 GHz antipodal fermi-linear tapered slot antenna (AFLTSA) 1×8 array for millimeter wave applications is presented in this paper. The substrate integrated waveguide (SIW) feeding structure is used to excite this proposed antenna. The proposed antenna has a sine corrugation to improve the radiation characteristics of the antenna. The simulated results of the single element yields a wide bandwidth between 30-40 GHz with a high gain of 12.15 dB and a side lobe level better than 17.85 dB in E-plane. This antenna is further simulated for 1×8 antenna array which yields a high gain of 20.1 dB with a side lobe level better than 22.5 dB in E-plane. The objective of this work is to have a high gain and lowside lobe level for this proposed array structure. The work is simulated using AnsoftHFSS and CST Microwave Studio software.