Fast methods for evaluating the electric field level in 2D-indoor environments

When estimating the electric field level in an indoor environment, the usual complexity of the geometry and its large electric size make it necessary to deal with asymptotic assumptions, also known as high frequency techniques. But, even with these assumptions, the computational complexity, and the CPU-time cost, can be very high. Considering this drawback, this paper proposes the implementation of a "Neural Networks System" for fast calculations of the Electric field in 2D-indoor environment

Antenna measurement and diagnostics processing techniques using unmanned aerial vehicles

European Conference on Antennas and Propagation (EuCAP) (13th. 2019. Krakow, Poland

Unmanned aerial system for antenna measurement and diagnosis: evaluation and testing

This contribution analyses the performance of an unmanned aerial system for antenna measurement (UASAM) for different kinds of measurement scenarios. UASAM is conceived for antenna diagnostics and characterisation at the operational location of the antenna under test (AUT). The system measures the amplitude of the near field radiated by the AUT. Then, these measurements are post-processed using phase retrieval techniques and equivalent currents methods to obtain an electromagnetic model of the AUT. This model can be used for antenna diagnostics and for evaluating the far field pattern. Similar to antenna measurement systems in anechoic chamber, UASAM allows defining different acquisition grids depending on the type of AUT (planar, cylindrical, arc cylindrical), which also influences the flight time. In addition to this, the capability to measure circularly polarised antennas from amplitude-only measurements is presented, discussing the limitations found during the tests, and comparing the results with those from measurements at a spherical range in an anechoic chambe

Complex Impedance Transformers Based on Branch-Line Hybrid Couplers

A topology, equations and design methodology for complex impedance-transforming branch-line hybrid couplers are presented. This method also allows the realization of real impedancetransforming to higher impedances. Limitations for real, imaginary and complex impedances are discussed. Test results are shown for a 3 dB 50 to 450 Ω hybrid coupler, at a 2 GHz center frequency, with a 21% bandwidth, an amplitude balance of 4.35 ± 1 dB and a phase balance of 92.16◦ ± 8.8◦. To showcase the complex impedance scenario, two 3 dB 50 Ω to 70 − 200j Ω are measured at a 2 GHz center frequency. One of these couplers uses a technique for reducing the chip size, yielding a 22.5% bandwidth, 4 ± 0.9 dB amplitude balance and 93.22◦ ± 6.74◦ phase balance, while accomplishing a 25% size reductio