Design and analysis of miniaturized integrated antenna with direct conversion transceiver for wireless communications applicaions

In this paper, the design of a compact miniature and low cost rectangular microstrip patch antenna integrated with 90° hybrid coupler, Wilkinson power divider and circulator for direct conversion, or zero IF transceiver. The frequency chosen is at 2.4 GHz, which is of particular interest wireless application. The finite element method (FEM) simulation is employed to analyze the entire structure. Different parametric solutions have been optimizing the proposed structure components. In the fabrication process, the proposed structure is printed on a Rogers RO3010 substrate with a dielectric constant of 10.2 and a thickness of 0.635 mm. The 90° hybrid coupler can act as a phase shifter to provide the necessary 90° characteristics to operate with I/Q signal for direct conversions while the circulator can act as R/T switch. The measured characteristics that are presented here have 94.98% power transmitted at input port, 99.999% gain in transmission side and 92.59% gain in receiving side.