Microstrip U-shaped dual-band antenna

This paper presents the design of a dual-operation antenna having microstrip configuration. The chosen dual-operation frequencies are that of indoor mobile system; 0.9 GHz and 2.4 GHz. The design starts with a microstrip square patch antenna being fed by a coaxial probe from underneath the substrate. An FR4 material was used for the design. The antenna was first cut into U-shaped configuration to operate at lower frequency of 0.9 GHz. A smaller square patch was then separately designed to operate at the lower frequency of 2.4 GHz. The feeding is similar, i.e coaxial probe feed. Successive simulations were performed on both antennas. Upon achieving a good impedance match at the input of the U-shaped antenna, the antenna was then integrated with the separately designed smaller square patch element. The smaller patch was coupled to internal region of the U-shaped configuration. The integrated U-shaped antenna was then optimized through successive cycles of simulations in order to operate well at the two frequencies of operations.