Principles of implementing coaxial microwave connectors for modern radioelectronic systems

Many modern radioelectronic systems are based on antenna arrays such as APAA (active phased array antenna) or DAAR (digital active array antenna), which require specialized connectors of new types and design solutions for the input/output of the microwave signal. The aim of this work is to improve the performance and reliability of coaxial microstrip connectors and coaxial waveguide transformer connectors of longitudinal type. The paper analyzes the arrangement principles of antenna feeders in modern radioelectronic systems with microwave connectors and substantiates the need to create new types of specialized microwave connectors. The authors demonstrate the issues that arise when using known coaxial microstrip connectors with threaded joints in antenna arrays. The paper considers the principles of implementing a cut-in microwave connector with hyperboloid contacts and its advantages, as well as the design of such a connector, i. e., the block coaxial microstrip transition and the cable part. The main technical parameters of cut-in microwave connectors are given. Using the analysis of the advantages and drawbacks of the known coaxial waveguide junction, the authors develop the requirements for the creating new microwave connectors of this type. The paper presents a design version of the longitudinal coaxial waveguide transformer connectors and their main characteristics.The considered design versions of the cut-in coaxial microstrip connector and the longitudinal coaxial waveguide transformer connector were manufactured and their characteristics were carefully studied. Analysis of the research results and measured parameters allow asserting that the proposed technical solutions are reliable, reproducible, can be mass produced, and thus can be recommended for use in modern radioelectronic systems.

Identifying Near-Perfect Tunneling in Discrete Metamaterial Loaded Waveguides

Mu-negative and epsilon-negative loaded waveguides taken on their own are nominally cut-off. In ideal circumstances, and when paired in the correct proportions, tunneling will occur. However, due to losses and constraints imposed by finite-sized constituent elements, the ability to experimentally demonstrate tunneling may be hindered. A tunnel identification method has been developed and demonstrated to reveal tunneling behavior that is otherwise obscured. Using ABCD (voltage-current transmission) matrix formulation, the S-parameters of the mu-negative/epsilon-negative loaded waveguide junction is combined with S-parameters of an epsilon-negative loaded waveguide. The method yields symmetric scattering matrices, which allows the effect of losses to be removed to provide yet clearer identification of tunneling.