S. Verdeyme

High performances of shielded LTCC vertical transitions from DC up to 50 GHz

This paper reports on research on two generic shielded vertical transitions in low-temperature cofired ceramic technology. These interconnections are simulated and optimized by three-dimensional electromagnetic simulations. The first circuit, a coplanar waveguide (CPW) or microstrip-to-stripline transition, presents great experimental performances from dc up to 50 GHz, and the second, a CPW-to-waveguide transition, is defined for Q-band applications.

Simple Electromagnetic Modeling Procedure: From Near-Field Measurements to Commercial Electromagnetic Simulation Tool

As the first part of a study that aims to propose tools to take into account some electromagnetic compatibility aspects, we have developed a model to predict the electric and magnetic fields emitted by a device. This model is based on a set of equivalent sources (electric and magnetic dipoles) obtained from the cartographies of the tangential components of electric and magnetic near fields. One of its features is to be suitable for a commercial electromagnetic simulation tool based on a finite element method. This paper presents the process of modeling and the measurement and calibration procedure to obtain electromagnetic fields necessary for the model; the validation and the integration of the model into a commercial electromagnetic simulator are then performed on a Wilkinson power divider.

CAD applying the finite-element method for dielectric-resonator filters

The progress of numerical techniques now permit us to analyze rigorously complex devices such as dual-mode cavity multipole filters or planar passive elements for coplanar monolithic microwave integrated circuits (MMICs). In this paper, we describe a rigorous design of dielectric resonator (DR) filters applying the finite-element method (FEM). We first present a dual mode coupling technique which replaces classical DRs, coupling, and tuning screws, which are commonly used in dual-mode filters, by slotted DRs. Next, a new theoretical analysis based on the contribution to the dual-mode filter response of the first DR hybrid mode and of higher order modes is described. This analysis can be applied to any type of microwave dual-mode filter. It allows us to define a procedure which explains the presence and controls the position of the two transmission zeros in the filter responses. In this paper, this procedure has been applied to improve filtering performances of a dual-mode DR filter. Finally, a synthesis method is developed to rigorously design for the first time, a four- and an eight-pole slotted DR elliptic filters. The experimental results were obtained with no tuning and the theoretical ones show good agreement.

Linear and nonlinear FET modeling applying an electromagnetic and electrical hybrid software

A new approach is presented in this paper to help the modeling of complex active microwave devices like field-effect transistors. This hybrid method couples an electromagnetic three-dimensional simulator to characterize the extrinsic part and a circuit software to introduce the contribution of the component intrinsic part. The interests of such approach are diverse and are discussed in this paper. Theoretical linear and nonlinear results are compared with measurements and show good agreements.

LTCC reduced-size bandpass filters based on capacitively loaded cavities for Q band application

The filter presented here is composed of cavities delimited in a LTCC substrate by a periodic lattice of metallized via-holes. The resort to LTCC technology permits us to improve the structure bulk by adding capacitive posts in the middle of the cavity. I/O CPW feeds are printed on the top face of the substrate and are suitable for planar circuit integration. A filter, functioning around 42.6 GHz with bandwidth at -3 dB of 7% and insertion losses lower than -0.6 dB has been designed and realized with success.

Finite elements for microwave device simulation: application to microwave dielectric resonator filters

The two-dimensional (2-D) and three-dimensional (3-D) finite element methods (FEMs) are applied to compute the exact scattering parameters (taking into account the transmission lines) of dielectric resonator (DR) filters. These filters act in TM or hybrid modes. A sensitivity analysis is also performed to predict the influence of the geometrical parameters on the devices responses. Examples of one, two, and three DR filters are given. Experimental results are in good agreement with theoretical ones. >

Narrow Ka Bandpass Filters Made Of High Permittivity Ceramic By Layer-By-Layer Polymer Stereolithography

Electromagnetic bandgap (EBG) concept is used to create cavity by dimensioning a variant cell (or defect) inside a 2D EBG material. Compact high unloaded Q cavity (Qu ~ 2500) and narrow two and three pole filters are designed in Ka band. They are manufactured by layer-by-layer stereolithography and made out of high permittivity yttria-stabilized Zirconia. Measurements of the three pole filter working at 33.45GHz exhibits an 1.05% bandwidth and an insertion loss of 1.7dB. These specifications are close to the theoretical values of 33GHz (1.5% shift in central working frequency) and 0.95% bandwidth

Microwave device combining filtering and radiating functions for telecommunication satellites

An original new design of microwave structure for integrating filter and antenna functions on a single device is presented. The structure is composed of a partially metallized dielectric plate enclosed in a parallelepipedic cavity. This topology allows a high integration in a planar environment type, and is suitable for high frequency filtering and power applications. In order to validate the multilayer radiant filter concept, an open two-pole filter using two superposed cavities coupled by a metallic iris is presented. Its filtering and radiating functions are optimized at the same time to present some required electrical performances. Moreover, to show the variety of uses of the antenna, two examples are described. The first one presents a coupled array of two radiant filters, and the second one an antenna with circular polarization radiation.

Finite element method for rigorous design of microwave devices using photonic band gap structures

In this paper, we present theoretical and experimental analyses of microwave devices using photonic band gap materials. These analyses are applied to design volumic or planar microwave filters. The experiments were conducted at 9-14 GHz to validate the concept which could be applied to millimeter frequency band (60 GHz) filters.

A new planar type dielectric resonator for microwave filtering

This paper is devoted to high electrical performance resonator realization for multilayer filter applications. A partially metallized substrate is shielded in a metallic cavity and excited by coplanar lines directly integrated on the dielectric resonator. This structure is suitable for high frequency filtering and power applications, and presents the advantage that it can be easily manufactured. Moreover, a new coupling technique without tuning is presented to realize a 2-pole filter. Experiments are performed to verify the theoretical design.