P. Guillon

Microwave tunable active filter design in MMIC technology using recursive concepts

In this article, two active filters in the X-band, using low frequency transversal and recursive principles are presented. Previously implemented in hybrid technology, those two structures are developed here using MMIC technology. In a first step, studies of the different functional blocks leading to the design of such original structures are described. Then we validate our approach with the measured results for these two filters.<<ETX>>

An electromechanical model for MEMS switches

This paper presents a new dynamic and parametric model of a capacitive micro-electromechanical switch electro-statically actuated. It is built of elementary electrical equivalent-circuit blocks constructed of voltage-controlled current sources. The model describes the nonlinear mechanical behavior of the membrane movement, which allows the computation or the bridge capacitance. It can be inserted as a model to perform simulations at microwave frequencies. All the switch parameters such as dimensions and materials properties are adjustable.

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.

New classes of microstrip resonators for HTS microwave filters applications

The rapid growth of mobile communication means creates a great interest for the use of the superconducting technology, especially for base station and satellite communication systems. Planar devices with HTS films allow one to conceive narrowband filters with very low loss and small dimensions. A novel class of cross shaped planar resonators is proposed for superconducting applications. This includes dual-mode and single-mode resonators. A four pole elliptic function filter at 4 GHz is realized and measured at room temperature. Theoretical and experimental results are presented.

Automatic frequency control techniques for microwave active filters

The paper discusses Phase Locked Loop (PLL) and Magnitude Locked Loop (MLL) techniques based on voltage controlled filter (VCF), for the automatic frequency central (AFC) of active filters. Applications to a microwave planar filter are considered. Theoretical analysis, simulated and measured results are presented for both phase and magnitude control circuits enabling the filter to accurately track a reference signal.

Design concept for microwave recursive and transversal filters using Lange couplers

The authors focus on the use of Lange couplers in the design of passive recursive and transversal filters in the microwave frequency range. A simple numerical method for the computation of the filter parameters is described. A synthesis example is given to illustrate the techniques for the wideband filter case. It is shown that Lange couplers can be effectively employed in the design of recursive and transversal filters. Analytical, computer-simulated, and experimental results are preserved for two passive bandpass filters which were implemented on a Duroid substrate in the 3-5-GHz frequency range. Good agreement was obtained between the theoretical and the measured S-parameters for the filters.<<ETX>>

Theoretical and experimental analysis of microwave tunable recursive active filters using power dividers

It is shown how power dividers can be effectively employed in the design of microwave recursive filters in strict accordance with low-frequency principles. Analytical, computer-simulated, and experimental results are presented for an active recursive bandpass filter, and for a newly developed tunable recursive active filter employing a reflection-type microwave phase shifter and implemented on a Duroid substrate in the 2.75-3.75-GHz range. The last step in the filter design was to insert a classical reflection-type analog phase shifter structure directly into the recursive loop, to help in the realization of a tunable recursive response. Measured S-parameters of the circuits show excellent agreement with theoretical analysis.<<ETX>>

Planar Ka-band high temperature superconducting filters for space applications

The impressive explosion of the satellite communication systems during the last few years has led to new constraints in regards to filtering requirements. The development of multimedia satellites and the saturation of the operational frequency bands, necessitates an increase in frequency coverage. This paper presents the design of High Temperature Superconducting (HTS) preselect receive fitters for communication satellites. Attention has been focused on obtaining low insertion loss and small dimensions, at frequencies of 4 GHz and 30 GHz.