EXXELIA, A EUROPEAN SOURCE OF HIGH Q FACTOR DIELECTRIC RESONATORS
Exxelia presents its new dielectric resonator, the E7000 series. The series has been designed for high-end filters where Q factor is critical, especially in space or military applications.
Operating frequencies in wireless communications have shifted towards high frequency band and thus frequencies higher than 1 Ghz are now commonly utilized. In addition, the microwave frequency spectrum becoming severely crowded and sub-divided into many different frequency bands, designers are systematically looking for resonators giving them a narrow bandwidth with smaller size.
Dielectric resonators are designed to replace resonant cavities in microwave functions such as filters and oscillators. Exxelia Temex, daughter company of Exxelia Group, has developed with support of ESA and CNES, a new high-end dielectric material, E7000 series, designed for high-end filters where high Q factor is requested.
E7000 is Ba-Mg-Ta materials based that combines an ultra-high Q factor and the possibility to get all the temperature coefficients upon request. E7000 provides high-performance requested for space use in the frequency range 5 to 32 GHz, and guarantees up to Qxf > 250 000 at 10GHZ.
Typical applications: Satellite multiplexing filter devices, radio links for communication systems (LMDS),
HIGH VOLTAGE CERAMIC CAPACITORS BASED ON BRAND NEW DIELECTRIC MATERIAL
No more compromises between stability and capacitance! The brand new C48X material combines most advantages of NPO and X7R dielectrics, enabling the new high power and high frequency ceramic capacitor range to provide great stability in voltage, high capacitance, great dissipation factor and fast charge/discharge. Miniaturization is a driving need for future electronics pieces of equipment. This evolution, true whatever the application, leads Exxelia Technologies (ex-Eurofarad) to develop a brand new high voltage ceramic capacitors range based on a new dielectric material named C48X, combining most of the advantages of NPO and X7R dielectrics. Compared to X7R material, C48X dielectric allows to get the same capacitance values under working voltage with the unrivaled advantage of a very low dissipation factor (less than 5.10-4). Besides, it can also withstand very high dV/dt, up to 10kV/μs, which makes it the solution of choice for pulse and fast charge/discharge applications. Thus capacitors with C48X dielectric appear to be ideally suited for power applications where heat dissipation may be detrimental to performances and reliability. Exxelia Technologies’ capacitors based on the C48X material have been developed from 200V to 5kV with chip sizes ranging from 1812 to 16080, allowing a maximum capacitance value of 10μF 200V (10 times more than with an NPO ceramic). The standard stacked versions are proposed with a maximum capacitance value of 47μF 200V. Regarding the mounting of these capacitors, many configurations are possible to be compatible either with surface mounting or through-hole mounting. All these versions can be suitable for space use and can be designed in order to avoid any whisker growth risk (10% min lead in all tin-lead alloys used). The introduction of the C48X range in the EPPL (European Space Agency Preferred Parts List) for space is in progress for sizes 0603 to 6560 from 100V to 1kV up to size 1210 and up to 5kV until the size 6560).
New Invar Tuning Elements with Self-Locking System
Working frequencies in Space applications are shifting to Ka, Ku or even Q band, while cavity filters are undergoing the general trend towards miniaturization: this context calls for a much more precise and stable tuning element now offered by Exxelia Temex, daughter company of Exxelia, through their last innovative and unrivalled solution to incorporate a self-locking system into their Invar Tuning Elements. Invar-36 is a unique Iron-Nickel alloy (64 % Fe / 36 % Ni) sought-after for its very low coefficient of thermal expansion. With 1.1 ppm. K–1 between 0°C and 100°C, Invar-36 is about 17 times more stable than Brass which is the most traditional and common alloy Tuning Elements are made of. The working temperature range in Space is so wide that this property becomes essential for a reliable and stable cavity filter tuning. Self-locking system is a technology commonly used on Tuning Element made of Brass or other soft “easy-to-machine” alloys but is innovative and pretty advanced when applied to hard and tough Invar 36. The design consists of two threaded segments separated by two parallel slots. After cutting both parallel slots, the rotor is compressed in its length in order to create a plastic deformation. Thus, an offset is induced between the two threaded segments which generates a constant tensile stress in the rotor from the moment threaded segments are screwed.