Miniaturized Vivaldi Tapered Slot Antenna (VTSA) with Microstrip to SIW Feed Structure for X Band Application

Vivaldi tapered slot antenna (VTSA) families are low-cost, lightweight, and have a simple design structure with good electrical performance and consistent impedance over a wide frequency range. It can be fabricated on a fragile substrate to be used for various applications like an aircraft wing or in wearable networks. One biggest issue with this antenna is impedance matching. In this design, an antipodal Tapered slot antenna is used. The proposed antenna’s feed structure used a SIW (Substrate Integrated Waveguide) to microstrip transition. It allows us to design the characteristics of an antenna on a common substrate while maintaining a high-quality factor. The structure is simulated in CSTMWS (CST Microwave Studio) and the equivalent circuit of the transition part is also evaluated using ADS software tools. The operating frequency range of the structure is between 8 and 12 GHz (X band). This band has potential uses in radar, imaging, medical, space communication, and military applications. The whole structure is fabricated on the RO4003c substrate and measurements are taken with a VNA. The simulated and measured results are found to be very close to each other. The designed structure has a 40% percentage bandwidth and the overall dimension is 33 × 14 mm2.