Low Loss and Ultra Flat Rectangular Waveguide Harmonic Coupler

Recently, communication networks are evolving dramatically to meet the human dynamic needs as well as provide the required support for the massive expansion in future applications. This fosters the research in the mm-wave components to create a new infrastructure for these applications. As a result, the electrical characteristics of the designed components in terms of the bandwidth and the linearity have to be evaluated in an accurate way. The linearity of the mm-wave components is evaluated through the assessment of the inter-modulation of these components, especially at the second harmonic band. In this paper, a −17-dB harmonic coupler is designed to pick a strong sample at the second harmonic, while suppressing the fundamental signal at the coupled port. A design procedure for the proposed harmonic coupler is presented and illustrated. The fabricated unit is silver plated to minimize the losses, where the measured coupling at the second harmonic band shows an excellent agreement with the simulated ones. In addition, the measured coupling level at the fundamental band is below −75 dB

Printed Ridge Gap Waveguide 3-dB Coupler: Analysis and Design Procedure

Communication systems are witnessing an outstanding revolution that has a clear impact on all aspects of life. The world technology is drifting towards high frequency and data rate solutions to accommodate the future expansion in applications such as 5G communications. The 5G technology will offer advanced features in the mm-Wave frequency band which requires intelligent subsystems such as beam switching. Therefore, the microwave components, especially couplers, still need a significant improvement to follow the rapid variations in future technologies. One of the most recent and promising guiding technologies for mm-Wave applications is the printed ridge gap waveguide (PRGW). In this paper, a design of 3-dB planar quadrature hybrid coupler based on PRGW is presented. The proposed design has superior characteristics such as compactness, low loss, and low dispersion device. The prototype of the proposed coupler is fabricated and tested, where the measured and simulated results show an excellent agreement

Graphene-based terahertz reconfigurable printed ridge gap waveguide structure

Graphene-based microwave devices have enabled reconfigurability, thus paving the way to the realization of flexible wireless terahertz systems with featured performances. Despite great progress in the development of graphene-based terahertz devices in the literature, high insertion loss and wide tunable range are still significant challenges at such high frequencies. In this work, we introduce the use of graphene to implement a reconfigurable printed ridge gap waveguide (RPRGW) structure over the terahertz frequency range for the first time. This guiding structure is suitable for both millimeter and terahertz wave applications due to its supporting quasi-TEM mode, which exhibits low dispersion compared to other traditional guiding structures. The presented solution is featured with low loss as the signal propagates in a lossless air gap, which is separated from the lossy graphene elements responsible for the reconfigurable behavior. In addition, this guiding structure is deployed to implement a tunable RPPGW power divider as an application example for the proposed structure