Analysis of dual-frequency operating microstrip antenna fed by coplanar waveguide using method of moments in spectral domain

At millimeter wave frequencies, the loss in the transmission line is signif icant. To alleviate this problem, a quasi-optical mixer will reduce the tra nsmission loss by combining the antenna and the mixer. The RF and the local signals at two different frequencies are received spatially, and the inter mediate frequency is generated immediately. To realize this function, there is a microstrip antenna fed by a coplanar waveguide to operate at two freq uencies. In this paper, the spectral domain method is used to analyze the i nput characteristics of the 1/20 scale model of this antenna at microwave f requencies. It is shown that the antenna can be operated at two frequencies independently. Further, the radiation characteristics of this antenna are evaluated in terms of the absolute gain. (C) 2000 Scripta Technica.