A Noble UWB Array with Band Notch Characteristics

A miniaturized four-element microstrip array of dimension (22 × 19 × 1.58) mm³ has been designed for ultra wideband (UWB) application. Unlike existing UWB arrays, the new UWB array is proposed for multiband applications. The key contribution of this paper is that both the layers (upper and lower) of FR4 substrate have been used to design the radiating elements for achieving a compact UWB structure. It is a challenging task for the researchers to design a miniaturized UWB array that offers uniform gain as gain is the major limitation of a UWB antenna. In this paper, four antenna elements (two-element array on the upper surface and other two-element array on the lower surface) of same dimension of the each element have been designed in order to achieve a reduced size of the array. Array on the top surface has been connected with the array in the bottom surface through a cylindrical via of diameter 1.0 mm. This type of array design will open up a new dimension for the UWB antenna array designers by avoiding the necessity of large substrate area. Furthermore, a U-shaped microstrip resonator has been integrated with the array structure in the lower layer and as a result, a notch band has been created at WLAN band. The array has been studied both numerically and experimentally. Prototype antennas with two and four-element arrays have been fabricated, tested and a remarkable agreement has been observed between the measured and the simulated results.