Laëtitia Rigaudeau

Ka-band Lange coupler in multilayer thick-film technology

A 3-dB Ka-band Lange coupler was implemented in a multilayer thick-film technology, which avoids the drawbacks of planar technology, e.g. bonding-wires and the limitation of the coupling level induced by the minimal resolution of the slot between the coupled lines. The coupler was realized and measured by using 50-Ω thick-film resistors as terminations. Finally, the electrical performances exhibited by the proposed coupler proved to be good with a coupling level of 4.2 dB at the central frequency, a return loss greater than 15 dB and isolation greater than 20 dB in the coupler passband.

When new needs for satellite payloads meet with new filters architecture and technologies

To cope with the economical and technical demands of the market and to compete with terrestrial networks, satellite operators and manufacturers will need to upgrade their satellites and services. Nowadays, most of commercial satellite payloads are designed for a predetermined service and lack flexibility. Future communication satellites have to become more flexible and shall provide capacity at the lowest cost. The upcoming new needs lead to a major impact on the architecture at satellite payload level. RF and microwave filters are one of the most affected by the derived equipment specifications. The required out-of-band rejection close to the useful bandwidth will become more stringent (better than 40 dBc) while saving size and mass by more than 30% compared to the heavy mechanical cavities used today. Advanced technologies, like ceramic 3D stereolithography or Surface Integrated Waveguide technology presented in this paper are very promising solutions to overcome these requirements. Moreover, tunable filters could be a relevant option to simplify payload architectures by giving more flexibility on the frequency plan and/or bandwidth. Today, agile filters are not available in space equipments but some new technologies presented in this paper, such as MEMS technologies or ceramic based flexible filters, have now the capability to comply with space environment constraints. Finally, new synthesis method techniques could help saving mass (by 30% or more) of future OMUX equipments.

150 GHz Band-Pass Filter Using LTCC Technology

A low temperature co-fired ceramic 150 GHz bandpass filter is, for the first time, designed and manufactured. Experimental electric performances are encouraging and validate the use of LTCC technology at submillimeter wave range. A Chebyshev 2-pole bandpass filter is achieved, with 1.6% bandwidth and 4.6 dB insertion loss. The unloaded quality factor is found to be 290.

LTCC Millimeter Wave Device Combining Both Filtering and Radiating Functions for Q band Applications

An original new design of microwave LTCC (low temperature co-fired ceramic) structure integrating a resonator and a patch antenna on a single device is presented. The structure is composed of a U-shape resonator that is magnetically coupled to the patch antenna. In order to validate the radiant structure concept, a two pole filter is designed using both the resonator resonance and the patch antenna one. Experimental results presented in this paper validate this very compact structure design

Mixed LTCC Ultra Compact S-Band Filter with Wide Multispurious Stopband

In this paper, two main objectives were validated. The first one was to develop and validate an original new hybrid Low Temperature Co-fired Ceramic process mixing both low- permittivity (low-K) and high-permittivity (high-K) materials in the same substrate. This approach proceeds to be very efficient in decreasing circuits dimensions. The second objective was to design a novel compact S-band filter based on this new technology, with high electrical performances and wide multispurious stopband. A two-pole bandpass filter functioning at a central frequency f0 = 2.52 GHz with 13 % relative bandwidth and very low insertion losses was optimized and manufactured successfully, validating the technology and the theoretical approach. The conceived structure is very compact and presents an excellent frequency isolation.

Quasi-elliptic 150 GHz highly selective LTCC filter

In this paper, and for the first time to the best of our knowledge, a very challenging 4-pole quasi-elliptic filter in the submillimetric wave range is studied and fabricated by the LTCC technology. The proposed 4-pole filter, centered at 150 GHz with 2 GHz band pass, is described and the coupling apertures used to provide the required positive and negative couplings are studied. The measured response is in very good agreement with the predicted behavior with a central frequency of 149.7 GHz (0.2% variation) and a 2.02 GHz band pass. The obtained manufactured filter is compact in size (3.32 mm x 2.36 mm x 0.6 mm), has a high performance with 5.5 dB insertion loss at the central frequency and a transmission attenuation over 20 dB for fo ± 1.6 GHz. Index Terms Low temperature co-fired ceramic (LTCC), quasi-elliptic filter, resonant cavity, submillimeter wave range.

Compact LTCC millimeter wave radiating filter dedicated to antenna array

An original new design of microwave LTCC (Low Temperature Co-fired Ceramic) structure integrating a resonator and a patch antenna on a single device is presented. The structure is composed of a U-shape resonator that is magnetically coupled to the patch antenna. In order to validate the radiating structure concept, a two pole filter is designed using both the resonator resonance and the patch antenna one. Experimental results presented in this paper validate this very compact structure. Then, a new design has been studied composed of two elementary radiant filters in order to realize linear array of patch antennas. The first results (return loss and radiation pattern) are very encouraging.