Super Wide Band, Defected Ground Structure (DGS), and Stepped Meander Line Antenna for WLAN/ISM/WiMAX/UWB and other Wireless Communication Applications

This paper presents a new shape (s-shape monopole) of a super wideband antenna using stepped meander lines, a quarter waveguide transformer feeding line, and a defected ground structure (DGS). The antenna will be used for multiple wireless communication applications like WIMAX/WLAN/ISM/UWB, and also for several wireless communication applications. The total dimensions of the proposed antenna are 35 mm × 35 mm × 1.57 mm or 0.36 λo × 0.36 λo × 0.016 λo, which are the corresponding electrical dimensions with free-space wavelength (λo) at the lower operating frequency. The antenna is designed and simulated into two steps: the first (Antenna 1) covers a bandwidth of 18.2 GHz, while the second (Antenna 2, using DGS) covers a super wide bandwidth of 37.82 GHz (3.08–40.9 GHz). The measured fractional bandwidth and bandwidth ratio of the antenna are 174.68% and 13.009:1, respectively, which is operating from 3.09–40.2 GHz. The maximum calculated gain and efficiency are 5.9 dBi and 92.7%, respectively. The time-domain performance is good due to the calculation of the system fidelity factor, group delay, and its linear and constant phase variation.

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.