C. Person

An original topology of dual-band filter with transmission zeros

This paper reports on a new topology of high-performance dual-band filters. This topology is derived from the Dual Behavior Resonator (DBR) filter. The resulting resonator is directly dual-band. It allows the control of two bandpasses separated by a transmission zero to ensure a high rejection level between them. Moreover, two other transmission zeros are located on either side of the two bandpasses. The possibilities offered by this structure are discussed and measurements are presented to validate the method.

Bandwidth and central frequency control on tunable bandpass filter by using MEMS cantilevers

This paper deals with a tunable bandpass filter topology which controls independently and simultaneously both the central frequency and bandwidth. This tunable filter results from the association of MEMS cantilevers, used as variable capacitors, with an original passive topology. The latter is based on dual behavior resonators (DBRs), each of them is constituted of low- and high-frequency open-ended stubs. The associated filter electrical response is characterized by tunable frequency transmission zeros. A millimeter bandpass filter with central frequency and relative bandwidth tunability of about 10 and 75%, respectively, is presented.

Integration of optimized low-pass filters in band-pass filters for out-of-band improvement

We propose an original structure for the design of high performance filters with simultaneously controlled band-pass and band-reject responses. The band-reject response is controlled due to the integration of low-pass structure. Thus, the spurious resonances of the band-pass filter are rejected up to the low-pass filter ones. In this way, we have to optimize the response of the low-pass structure in order to control the out-of-band response of the band-pass filters.

Optimization and miniaturization of a filter/antenna multi-function module using a composite ceramic-foam substrate

In view of optimizing a CPW-fed microstrip patch antenna, a composite ceramic-foam substrate is investigated. Using a global synthesis technique, a multilayer multitechnology miniature band-pass filter is integrated on the back-side ceramic while a microstrip patch is laid down on the upper foam dielectric. This combination leads to an efficient and compact multi-function module.

Integration of an Antenna/Filter Device, using a Multi-Layer, Multi-Technology Process

In this paper, we discuss about the synthesis and the implementation of a multi-function antenna/filter device, which appears as an optimum response in relation with the systems physical and electrical evolutions. Due to the extensive development of the uniplanar technology, our investigations concern the integration of a uniplanar slotline dipole directly in a standard Tchebyscheff band-pass filter. As a result, such a combination appears like a convenient solution for improving the performances of the basic antenna. To overcome technological constraints, we show that an optimum approach consists in the use of a multi-layer, multi-technology process. Preliminary experimental results prove the validity of this approach, and allow some extensions to more complex sub-systems.

Planar tri-band filter based on dual behavior resonator (DBR)

This paper reports on the application of dual behavior resonators to design triband filters. The principle is briefly presented by considering monoband, dual-band and triband filters. A circuit is proposed by using an approximate synthesis. Then, a hybrid (electromagnetic / circuit) simulation is performed to take into account the parasitic effects induced by the junction discontinuities and to allow a fast triband optimization in the same time. An example of layout with associated simulated and experimental results is proposed.

Original techniques for designing wideband 3D integrated couplers

In this paper, we propose some original technological configurations for implementing highly coupled wideband structures in a 3D environment. Thanks to a convenient combination of thinkable topologies, difficulties commonly encountered with a classical approach can be solved. Different design examples of couplers are given, and experimental and simulated results are presented.

Influence of design liquid crystal-based devices on the agility capability

This article deals with liquid-crystal-based tunable components: phase-shifters and patch-antennas. It reports on investigations about the influence of design on their characteristics. For phase-shifters based on an inverted microstrip line, the line design is paramount for improvement of phase-shift and figure-of-merit. Moreover, the use of liquid crystal in the design of patch antennas allows adjustment of the resonance frequency, and slot insertion results in size reduction with no decrease of performances. Both cases highlight the interest of liquid crystal in millimeter frequency devices.

Miniaturized and out-of-band improved bandpass filter in Si-BCB technology

This paper reports on the design of a 24 GHz bandpass filter. This device is developed in a multilayer BCB-Si technology to ensure the development of the system on a unique chip. Moreover the technique of integration of semi-lumped lowpass filters in bandpass filter is used to reduce the global size and eliminate spurious response of the filter. The general method to design this kind of filters is described and experimental results are presented.

Multi-Layer Thick-Film Technology: A Convenient Way to Design Compact and Efficient Microwave Components

In current communication systems, significant efforts are being made concerning the miniaturization of the different microwave integrated sub-functions involved. In addition to size considerations, acceptable performance and insensitivity to external phenomena (like temperature, vibrations, acceleration, etc ...) remain essential criteria for their validity (especially for spacial applications, mobile communications devices, etc...). in this way, Multi-layer Thick-film technology is very apprpriate for developing such compact and efficient integrated systems. The purpose of this paper is to show the possibilities and the interesting properties of this particular technological process. By considering simple test structures and using corresponding equivalent circuits, we have built numerous microwave functions, like filters, couplers, DC-Blocks, etc.. with good performances, rarely achieved before using the classical approach.