In the last two decades the use of mobile communication has increased quite rapidly. This also increases the importance of filters as an integral part of it. In microwave frequency range transmission line elements play an important role in designing the microwave circuit elements. Using the transmission line elements different types of microwave circuits such as filters, amplifiers, couplers etc. can be implemented very easily. Suspended stripline (SSL) usually has a larger cross-section which reduces the current densities on the metallization and also lowers the electric field strength in the dielectric. This reduces the losses.There is no radiation loss due to the shielding (mount) of the SSL. It is very difficult to integrate these types of filters having the SSL connections at the ports. The space requirement of these filters is increased due to the presence of the connectors. The transmission line structures connected to both ports need to be compatible with the circuit construction technique for integration. To meet this requirement microstrip connections are introduced to the ports.

Mohammad Shafiqur Rahman Tito is working as an assistant professor in Electrical and Electronic Engineering (EEE) department of Islamic University of Technology (IUT), an Organization of Islamic Cooperation (OIC),Board Bazar, Gazipur.