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Fully reconfigurable hexagonal-shaped comb-line filterplatform for prototyping and education purposes
In this paper, a completely reconfigurable comb-line bandpass filter is presented. Due to the modularity, different standard coupling matrix topologies like the folded form, cascaded triplets, and the cul-de-sac form can be implemented and tested. Circuit-based coupling matrices like the extracted pole topology can easily be realized as well. Different types of input-/output- and cross-couplings c
Surface impedance properties of a wire grid embedded in a chiral medium
The surface impedance characteristics of a wire grid composed of infinitely long parallel conducting wires embedded in lossless and lossy frequency-dispersive chiral background media have been investigated. Using wavefield decomposition approach for a chiral background and with the application of impedance boundary conditions for a wire grid, an analytic expression for the surface impedance of a w
A miniaturized CPW-fed on-chip UWB monopole antenna with band-notch characteristics
This paper presents the design and analysis of a miniaturized, coplanar waveguide-fed ultra-wideband monopole on-chip antenna with band-notch characteristics. By incorporating a ?U?-shaped slot in the feedline, a band-notch is realized in the frequency range of 7.9?8.4 GHz to avoid interference from the X-band uplink satellite communication system. The proposed antenna achieved good voltage standi
Effects of vibration on passive intermodulation of microwave connector
This paper investigates the generation of passive intermodulation (PIM) in coaxial connectors during vibration. A series of experiments were designed and the simulation model and method were proposed for understanding these phenomena. We found that PIM is mainly influenced by the contact stress and contact surface roughness during vibration. Thus, a power spectral density method is presented to id
Localization of unknown electromagnetic source using 3D-antenna arrays
In this article, we propose three-dimensional antenna systems for determining the position of electromagnetic radiation source at an unknown location. Received signal power at different antennas and position of radiation source are used as training data for Artificial Neural Network (ANN). It is found that, a well-trained ANN is computationally efficient and capable of predicting the unknown locat
A compact four-port UWB MIMO antenna with connected ground and wide axial ratio bandwidth
A new design method of an ultra-wideband circularly-polarized planar multiple-input-multiple-output (MIMO) antenna is presented in this paper. The proposed MIMO antenna consists of four unit cell antennas, being comprised of a microstrip feed line and a square slotted ground plane. In the proposed unit cell design, a circular stub is protruded from the ground plane strip for achieving circular pol
MRF volume 11 issue 5-6 Cover and Back matter
MRF volume 11 issue 10 Cover and Back matter
MRF volume 11 issue 10 Cover and Front matter
Behavioral modeling and digital pre-distortion techniques for RF PAs in a 3 × 3 MIMO system
Modern telecommunications are moving towards (massive) multi-input multi-output (MIMO) systems in 5th generation (5G) technology, increasing the dimensionality of the systems dramatically. In this paper, the impairments of radio frequency (RF) power amplifiers (PAs) in a 3 × 3 MIMO system are compensated in both the time and the frequency domains. A three-dimensional (3D) time-domain memory polyno