Barbara Bonnet

Miniaturized C-Band SIW Filters Using High-Permittivity Ceramic Substrates

This paper introduces an effective way to build efficient miniature C-band filters using high-permittivity ceramics. The objective was to evaluate the feasibility of such filters using commercial electromagnetic simulators and a conventional fabrication process. For the demonstration, the substrate integrated waveguide (SIW) technology was chosen. Compared with planar solutions, this configuration offers good quality factors and good electrical performances as a consequence. However, its dimensions are large, leading to unacceptably large footprints for many applications. The solution proposed in this paper is based on a ceramic substrate with a permittivity of 90, which allowed us to work with shorter wavelengths. In comparison with a standard alumina substrate (permittivity εr= 9.9, this approach makes it possible to reduce the footprint up to nine times. Two prototypes were realized on a Trans-Tech ceramic substrate (thickness = 635 μm, εr = 90, and tanδ = 9 · 10-4. The first prototype is a folded sixth-order SIW filter including a cross coupling combining coplanar waveguide probes and a thin microstrip line on an InterVia substrate. The second one is a folded eighth-order SIW filter without cross couplings. Here, we compare the sixth-order prototype with an identical one built on alumina. The eighth-order filter, which had no alumina counterpart, is a potentially useful alternative for situations where complex technological steps must be avoided.

Miniature UHF-Band microstrip filter based on a high-permittivity ceramic material

The miniaturization of embarked devices remains a major concern in the space sector. Alternative solutions based on the use of new ceramic materials with very high dielectric permittivity, enhanced electric properties and high temperature stability are worth being investigated. This paper reports on the design of an UHF-microstrip bandpass filter with drastic specifications and based on such a dielectric substrate of relative permittivity εr = 90. Simulation and measurement results highlight some of the possibilities offered by these particular materials.

3D Packaging Technology for Integrated Antenna Front-Ends

Thanks to Vertical Multi-Chip Module packaging technology (MCM-V), a novel concept of integrated antenna feed in Ka band has been developed. This technology enables the integration of active elements very close to the radiating surface, which reduces dramatically the weight and volume of the antenna. In this paper the different technological building blocks are described, and the measurements obtained on the first breadboard are discussed. The promising results obtained should lead to a major breakthrough for active receive antennas, driving down cost and complexity.

Design of high-permittivity ceramic UHF microstrip filter for a space application

The miniaturization of embarked devices remains a major concern in many applications and in particular in the space domain. Alternative solutions based on the use of ceramic materials with very high dielectric permittivity, enhanced electric properties and high temperature stability are worth being investigated. This paper presents the design of a 720 MHz central frequency microstrip bandpass filter. This filter use a ceramic with a relative permittivity ¿r = 90. Simulations, and measurements over a large range of temperature are presented.