A Fast Frequency Sweep – Green’s Function Based Analysis of Substrate Integrated Waveguide

In this paper, a fast frequency sweep technique is applied to the analysis of Substrate Integrated Waveguides performed with a Green’s function technique. The well-known Asymptotic Waveform Evaluation technique is used to extract the Padè approximation of the frequency response of Substrate Integrated Waveguides devices. The analysis is extended to a large frequency range by adopting the Complex Frequency Hopping algorithm. It is shown that, with this technique, CPU time can be reduced of almost one order of magnitude with respect to a point by point computation

An Integrated Radar Tile for Digital Beamforming X-/Ka-Band Synthetic Aperture Radar Instruments

This paper presents the first experimental assessment of a highly integrated dual-band dual-polarized antenna tile designed for synthetic aperture radar (SAR) digital beamforming (DBF) satellite applications. The demonstrator described in this paper is the first comprehensive experimental validation of an RF module providing the X-band and Ka-band (9.6- and 35.75-GHz) operation with custom downconversion stages. All the antennas, transitions, and downconversion chips are integrated in the same antenna tile fabricated using a customized 15-layer high density interconnect process. The designed tile goes to the limits of the proposed technology and for the high trace density and for the size of the vertical transitions. The proposed results represent the state of the art in terms of compactness for a DBF SAR RF module even though the demonstrator was manufactured with a standard low-cost technology. The experimental assessment proves the validity of the proposed manufacturing and integration approaches showing a substantial agreement between the performance of the individual blocks and of the integrated system

Antenna array elements for Ka-band satellite communication on the move

Two dual-polarised reflectarray unit cells for the folded reflectarray and one linearly polarized array element for direct radiating array for Ka-band SatCom on the move are presented in this paper. All of these antenna unit cells have multi-layered structure and are designed for the smart array antenna with beams that can be steered to large scanning angles. The unit cells for reflectarray are designed to operate at 29.5-30.8GHz band for both transmitting and receiving while the antenna element for the direct radiating array is designed to have a dual band operation: 29.5-30.8GHz for transmitting and 19.7-21.0GHz for receiving. These three antenna elements have a low profile and the simulation results show that they exhibit good radiation performance over the required frequency bands

A current-matrix model for metallic and dielectric postwall waveguides

Waveguide structure integration in planar substrates for use in microwave components has received considerable attention in recent years. Waveguides with side walls consisting of cylindrical posts (postwall waveguides or PWWGs) are of interest, since they are compatible with standard PCB fabrication technology and exhibit low loss. In this paper we present an electromagnetic model for PWWG building blocks, whose characteristics are described entirely in terms of equivalent electric and magnetic surface currents at predefined port interfaces consistent with Lorentz's reciprocity theorem. Introducing input and output surface currents, we determine the response of a block for a given port excitation. The expansion of the currents in terms of suitable bases results in a matrix that relates input and output currents. The scattering parameters of a building block are determined by expressing waveguide modes in terms of these bases. This facilitates the future integration of PWWG components in a microwave circuit simulator. We validate our model by comparing the results for simulated and measured uniform PWWGs implemented with metallic and dielectric posts