Design and development of harmonic suppressed miniaturized fractal hybrid couplers for wireless applications

Abstract

The demand for wireless connectivity in respect of voice video and data has posed new technological challenges for the future wireless systems The design and development radio frequency subsystems for wireless applications are a greater challenge RF subsystems include newlinemodulators mixer the transmit and receive antennas the wireless propagation channel and demodulators Among them mixer allows the important function of frequency conversion newlineRF hybrid couplers are fundamental building blocks of mixers It is also an essential component in the integration of amplifiers and beam forming antennas with respective subsystems When a hybrid coupler is realized in microstrip configuration radial and circular symmetric geometries are used However such hybrid coupler circuits have the disadvantage of having multiple non collinearly aligned ports Hence it is difficult to integrate with other adjoining devices such as power amplifiers Therefore it becomes necessary to use a vertically oriented feeding point This necessitates the use of using rectangular 180 hybrid coupler geometry It overcomes the newlinedivergence problem caused by the circular or radial geometry in view of the port alignment even though the size is not compact In order to achieve port alignments as well as maintaining the structure compactness rectangular shape hybrid coupler was introduced newline