Currently, artificial satellites are extensively used for scientific, military, and civil applications, particularly for telecommunications satellites.

This paper presents a concept of a tunable cavity resonator composed of a resonating cavity and a dielectric perturber. This tunable resonator is designed and measured to prove the tuning mechanism obtained by varying the angle of rotation of the perturber. A rotation from 0 to 90 produces a tuning ratio of 1:1.25, i.e., a tuning range of 22.2% around 11.5 GHz while maintaining an unloaded Q factor between 1500 and 2300. After this first experimental validation, a third-order bandpass filter is then designed and measured using the same base principle. Using a single mechanical movement, all three resonators' perturbers are synchronously rotated to create a third-order Chebyshev bandpass filter maintaining a 516±38-MHz bandwidth (for a return loss better than 10 dB) from 9.915 to 12.189 GHz. A 20.6% tuning range is then obtained at approximately 11 GHz with an estimated Q factor from 1400 to 2150. These performances have been obtained by using specifically shaped dielectric perturbers, which have been made by a ceramic additive manufacturing (AM) process (stereolithography). This technology has enabled the perturbers' specific geometries and embedded supporting elements to be feasible. A sixth-order Chebyshev bandpass filter has also been theoretically proposed using full wave simulations.

We investigate the microwave magnetic field confinement in several microwave three-dimensional (3D)-cavities, using a 3D finite-element analysis to determine the best design and achieve a strong coupling between microwave resonant cavity photons and solid state spins. Specifically, we design cavities for achieving strong coupling of electromagnetic modes with an ensemble of nitrogen vacancy (NV) defects in diamond. We report here a novel and practical cavity design with a magnetic filling factor of up to 4 times (2 times higher collective coupling) than previously achieved using one-dimensional superconducting cavities with a small mode volume. In addition, we show that by using a double-split resonator cavity, it is possible to achieve up to 200 times better cooperative factor than the currently demonstrated with NV in diamond. These designs open up further opportunities for studying strong and ultra-strong coupling effects on spins in solids using alternative systems with a wider range of design parameters. The strong coupling of paramagnetic spin defects with a photonic cavity is used in quantum computer architecture, to interface electrons spins with photons, facilitating their read-out and processing of quantum information. To achieve this, the combination of collective coupling of spins and cavity mode is more feasible and offers a promising method. This is a relevant milestone to develop advanced quantum technology and to test fundamental physics principles.

This paper proposes, for the first time to the best of our knowledge, two challenging LTCC multi-pole bandpass filters operating at 150 GHz for radioastronomy applications. Low-temperature co-fired ceramic (LTCC) technology is employed to realize these filters because it assures the high precision and compactness needed at this high frequency. The two filters are optimized by 3-D electromagnetic simulations and are validated by experimental results. Different positive and negative couplings, which are achieved by different coupling apertures, are studied. The five-pole Chebyshev filter has 8.4 dB of insertion loss in a 1.31% fractional bandwidth for 6.7 mm × 2.45 mm lateral dimensions. The four-pole quasi-elliptic filter is conceived to decrease insertion loss by decreasing the number of resonant cavities while conserving the same selectivity by introducing two transmission zeros around the passband. Beside 5.5 dB of insertion loss, this filter occupies a more compact circuit area (3.32 mm × 2.37 mm) and insures a very good spurious free region (16 GHz) around 150 GHz. Experimental results are in good agreement with the theoretical ones and validate the use of LTCC technology at such high frequencies over 100 GHz.

A first approach toward the integration of heterogeneous electronic circuit technologies and fully 3-D printed ceramic microwave devices is discussed in this work. Additive manufacturing (AM) capabilities are explored for the development of multifunction surface-mount compact components used in different RF front-ends’ scenarios. Monolithic ceramic bandpass filters (BPFs) are designed to operate in the $X$ -Band and to assess the typical limitations of ceramic stereolithography (SLA) processes. A post-fabrication tuning method based on a laser engraving strategy is presented to overcome the manufacturing constraints and carry out the filters’ correction. 2.5-D and 3-D printed four-pole filters were fabricated and tuned using the proposed methodology.

A study on the passive microwave components made by polymer additive manufacturing (polymer jetting) is presented. Different types of components (waveguides, couplers, power dividers, filters and antennas) are designed to be made in a single part. Using a simple and cost‐effective metallisation by applying silver paint, various prototypes with complex geometries have been manufactured to evaluate these proofs of concept and the robustness of the low‐cost approach to make microwave components. Different measurements show that the obtained filters can provide an acceptable unloaded Q factor of 400–500 for the operating frequencies of 12–22 GHz. Waveguiding structures such as a mode converter, which is used as a broadband antenna, have also notably efficiently worked up to the Ka band (36 GHz). Due to a remarkable accuracy of nearly 80 µm, the obtained results of the proposed coupler, power divider and antennas are consistent with the full wave simulations, which prove that the currently available three‐dimensional plastic printers can provide notably accurate prototypes to design original components.