**Abstract**

In today's modern communication systems, miniaturized and lightweight subsystems covering broad bandwidth are in much demand as they lead to realization of very compact and lightweight systems. A printed podal Vivaldi antenna with single as well as double cavities fed with strip line transmission line and operating from X band to KU band (8–18 GHz) is proposed. The comparison of antenna performance for single cavity and double cavity is also reported. Using double cavity, the miniaturization of antenna is possible as compared to single cavity Vivaldi antenna. The antenna is first designed using conventional theoretical approaches. Later, it is simulated using a 3D EM simulation software, CST Microwave StudioTM. The optimal value for taper length is 6.86455 cm and cavity diameter is 1.582 cm. Finally, the design is physically fabricated using PCB technology for carrying out practical measurement. The antenna's input impedance characteristic is measured in the form of S-parameter and VSWR using Vector network analyzer. VSWR less than 3:1 is achieved over the band from 8 to 18 GHz. The radiation pattern measurements are carried out in anechoic chamber. The proposed Vivaldi antenna is used for digital data transmission via satellites and for voice/audio transmissions.

**Keywords:** Vivaldi, broadband antenna, microstrip, VSWR, characteristic impedance
