Microwave Filters Based on New Design Concepts in Several Technologies with Emphasis on the Printed Ridge Gap Waveguide Technology

Microwave filters have been an interesting research topic for more than half a century. Since any communication system is required to use some microwave filters, considerable effort is being made to optimize the performance and size of these filters. As operating frequency is on the rise, filter design becomes more challenging with the demand for low insertion losses and low cost. As low cost might require the use of printed circuit technology, high performance demands waveguide technology that drives the cost to unacceptable levels. There is a need for a new technology that achieves both requirements of low cost and high performance. The new technology of ridge gap waveguide that was proposed in 2011 shows promising characteristics as a new guiding structure, especially for high-frequency bands. Therefore, it is necessary to design and propose classic or even new filtering devices on this technology. Here, we propose the use of this technology to design practical and efficient microwave filters. The work of this thesis can be divided into three major parts: (1) Developing efficient codes and methods to optimize the computationally expensive structure of ridge gap waveguide or any other large-scale microwave filter device. (2) Characterizing cavity structures on ridge gap waveguide and using them in the design of simple microwave filters. (3) The third part will discuss more advanced and practical filters, especially using printed ridge gap waveguide technology. The ultimate goal of this thesis is to design and propose state of the art designs in the field of microwave filters that can satisfy the requirements of today’s advanced communication systems and to be cost efficient and compete with other rival technologies. We achieved these objectives using efficient optimization, efficient design techniques, and fabrication of the models using advanced technology

Design of integrated diplexer-power divider

A new configuration is introduced to integrate diplexers and power dividers. The proposed configuration is based on coupling matrix. The design of the lumped element network is based on addition of an extra term to the conventional error function of the coupling matrix to decouple the two ports of the power divider. An optimized lumped element network is implemented successfully on an EBG based guiding technology known as ridge gap waveguide. The optimization of the physical structure is done efficiently by dividing the diplexer-power divider into many sub-circuits and analyzing the corrected delay response of them

Compact Integrated Full-Duplex Gap Waveguide-Based Radio Front End For Multi-Gbit/s Point-to-Point Backhaul Links at E-Band

This paper presents the design and realization of a high data rate radio front-end module for point-to-point backhaul links at E-band. The design module consists of four vertically stacked unconnected metal layers without any galvanic and electrical contact requirements among the building blocks, by using gap waveguide technology. The module components are a high-gain array antenna, diplexer, and circuitry consisting of a transmitter (Tx) and a receiver (Rx) monolithic microwave integrated circuits (MMICs) on a carrier board, which is successfully integrated into one package with a novel architecture and a compact form. The diplexer consists of two direct-coupled cavity bandpass filters with channels at 71-76 GHz and 81-86 GHz with a measured return loss of 15 dB and an isolation greater than 50 dB. A wideband 16 x 16 slot array antenna with a measured gain of more than 31 dBi is used to provide high directivity. The measured results show that the packaged transmitter provides a conversion gain of 22 and 20 dB at 76 and 86 GHz, respectively, with an output power of 14 and 16 dBm at 1-dB gain compression point, at the same frequencies. The packaged receiver shows an average conversion gain of 20 dB at 71-76-GHz and 24 dB at 81-86-GHz bands. A real-time wireless data transmission is successfully demonstrated with a data rate of 8 Gbit/s using 32-quadrature amplitude modulated signal over 1.8-GHz channel bandwidth with spectral efficiency of 4.44 bit/s/Hz. The proposed radio front end provides the advantages of low loss, high efficiency, compact integration, and a simple mechanical assembly, which makes it a suitable solution for small-cell backhaul links

Diplexer integration into a Ka-band high-gain gap waveguide corporate-fed slot array antenna

A multilayer integrated diplexer-antenna array module for Ka-band high capacity point-to-point backhaul links is presented. The proposed module is composed of three unconnected metal layers with a simple mechanical assembly and no electrical contact requirements between the distinct layers based on gap waveguide technology. A 7th order hybrid diplexer-splitter with a novel architecture is successfully integrated into a ridge gap waveguide corporate distribution network of a 16 716 slot array antenna. The measured input reflection coefficientsfor both Tx/Rx channels are below -13 dB with measured total efficiency better than 60% in the designed passband. The measured isolation of gain between the two channels is more than 55 dB

An E-band Antenna-diplexer Compact Integrated Solution Based on Gap Waveguide Technology

In this paper, a novel compact integrated antennadiplexer for Frequency-division duplex low latency wireless backhaul links at E-band is presented. The proposed solution is designed in a multilayer architecture with each layer having different functional blocks. The layers have been stacked on top of each other without any electrical contact requirement between them. This is achieved by using packaging property of gap waveguide technology. A corporate-fed 16 x 16 slot array antenna is integrated with a 5th order diplexer. The simulated reflection coefficients arc better than-13 dB for both input ports in the designed passbands. The simulated realized gains at the middle of channel 1 (73.5 GHz) and channel 2 (83.5 GHz) are respectively 31.8 dBi and 32.9 dBi, obtaining a high isolation of 50 dB between the two input ports