Dielectric-loaded L-band filters for high-power space applications

Abstract

The design and first experimental results of Tx and Rx L-band bandpass filters for a high-power satellite diplexer are presented in this paper. Designed in the framework of an ESA ARTES AT project, the filters are based on TM010 mode dielectric resonators. These resonators allow for better results in terms of volume occupation with respect to other dielectric resonators still maintaining high Q-factor values (>2000). Volume saving above 30% is achieved with respect to standard coaxial filters. The filter geometries and materials have been chosen in order to improve the power-handling and to cope with related critical issues for space applications (i.e. avoid any multipactor discharge in the operating RF power range and low-PIM response). Measurements of Tx filter show good correlation with the design in terms of central frequency, BW, and unloaded Q-factor (almost 3000). Measurements of Rx filter show a worse correlation with the design in terms of filter response shape. This is ascribed to size tolerances of one of the filter resonators. Multiple analyses are ongoing to remove this degradation in the final engineering model.

Very Compact Diplexer Based on Dual-Mode Dielectric TM-Mode Resonators

“…Accordingly, many diplexers were presented in the open literature based on various planar and waveguide technologies. In particular, loaded-waveguide diplexers have gained an increasing amount of attention because of their desirable features of more size miniaturization, high-Q, and good power handling capabilities [1]- [9]. For example, [1] presented an L-band combline diplexer for space applications with input power up to 1800 watts.…”

Compact Ultra-Wideband Bandpass Filter Using Additively Manufactured TM - Mode Dielectric Resonators

“…Thanks to their excellent characteristics and distinctive volume-saving capabilities compared to other 3-D technologies, TM-mode dielectric resonator (DR) filters are attracting increasing attention in high-performance narrowband applications including cellular base stations and satellite payloads [1]- [3]. For example, [1] introduced a compact base station filter using TM 010 mode DRs with fractional bandwidth of 1% at UMTS 1.95 GHz frequency band.…”

“…For example, [1] introduced a compact base station filter using TM 010 mode DRs with fractional bandwidth of 1% at UMTS 1.95 GHz frequency band. Also, narrowband 2.7% L-band TM-mode dielectric filters and diplexers were presented for high-power space applications in [3].…”

“…While small inter-resonator (IR) couplings of narrowband TMmode DR filters are commonly realized through transversal magnetic coupling configurations as in[1]-[3], unfortunately, they cannot provide the required large IR couplings for wideband filter applications similar to all other DR filter categories. In contrast and uniquely, the longitudinal…”

3D-Printed Dielectric Resonators for Quasi-TE112 Mode Singlets, Doublets and Dual-Mode Filters

“…For that reason, architectures that are known for high quality factors like microwave cavities and dielectric resonators have widely been used in satellite communication systems [3]- [5], and in addition, several different approaches to improving the quality factor of these types of filters are extensively described in the literature [6]- [16].…”