Aurélien Perigaud

Synthesis of Vertical Interdigital Filters Using Multilayered Technologies

Taking advantage of multilayer technologies, a vertical evolution of the interdigital topology is proposed with its associated synthesis method. In order to validate this filter topology, a 4-pole filter, centered at 10 GHz, and an 11-pole filter, centered at 6 GHz, have been designed and fabricated using low-temperature co-fired ceramic (LTCC) technology. Two other multipole filters have also been designed showing a large surface reduction with respect to equivalent interdigital filters. LTCC technology has been chosen for fabricating the filters, but the proposed topology can also be implemented with other multilayer technologies.

Design of Microstrip Lossy Filters for Receivers in Satellite Transponders

This paper compares several designs of lossy filters for receiver subsystems in satellite transponders. The reference design is a microstrip filter made of coupled hairpin resonators. Two approaches are investigated for improving the flatness of the reference design. The first approach combines nonuniform quality factor (Q) resonators in a transversal network. The second approach uses an inline network with resistive cross couplings. Lossy filter designs are compared to the reference, considering the same specifications and the same technology. The inline network with resistive cross-couplings is finally modified for designing absorptive filters, which protect the receiver from reflected waves. All filter configurations are fabricated and measured, showing a good agreement with electromagnetic simulations.

Multilayered Coupled Interdigital Resonator Filters for General Chebyshev Filtering Functions

This paper presents compact multilayer interdigital filters for realizing general Chebyshev (i.e., quasi-elliptic) filtering functions. Several coupling elements are proposed for implementing a wide range of couplings between quarter-wavelength resonators, which are placed on a unique layer or stacked thanks to a multilayer technology. Several multipole filters are designed and fabricated using low-temperature co-fired ceramic (LTCC) technology. Designs and experimental results are detailed in order to appreciate the potential of the proposed technology. The multilayer interdigital filters proposed in this paper are designed especially for electronic warfare specifications from S- to Ku-band.

Continuously Tuned Ku-Band Cavity Filter Based on Dielectric Perturbers Made by Ceramic Additive Manufacturing for Space Applications

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.

3D printing of microwave passive components by different additive manufacturing technologies

This paper presents an overview of the possibility offered by 3D plastic printers for a quick, simple and affordable manufacturing of working filters and other passive devices such as antennas. This paper thus goes through numerous examples of passive devices made with the Fused Deposition Modeling (FDM) and material jetting (Polyjet©) technologies and will highlight how they can now be considered as a solid companion to RF designers during an optimization process up to Ku and higher bands.

Multilayer Interdigital Structures for Compact Bandpass Filters Providing High Selectivity and Wideband Rejections

Two compact microwave filters designed using multilayer inter-digital resonators are introduced. The first structure combines vertically and horizontally coupled interdigital resonators for optimizing the surface occupation while realizing high-order filters. A 12-pole filter centered at 18 GHz, with a 2.4 GHz passband, is designed and characterized. The second structure is composed of stepped-impedance interdigital resonators for widening the upper stopband. The filter is centered at 3 GHz with a 0.9 GHz passband, and both simulated and experimental results show an extended stopband up to 21 GHz.

Dual-Mode Dual-Band Bandpass Cavity Filters With Widely Separated Passbands

A dual-mode dual-band cavity is proposed for the integration of compact dual-band filters with widely separated passbands. The basic structure is a cavity working on two distinct dual-modes, realizing a four-pole dual-band filtering function. An intermediate structure is also designed to validate coupling between dual-band cavities. Finally, two dual-mode dual-band cavities are coupled together for implementing an eight-pole filter with two passbands at 5 and 7.5 GHz, respectively. Prototypes are fabricated and measured for validating all designs, showing the relevance of the proposed concept.

A dual-mode dual-band bandpass cavity filter with widely separated passbands

A compact dual-mode dual-band filter with widely separated passbands is proposed for possible integration in a TX/RX front-end. The basic structure is a cavity working on two distinct dual-modes. The design of this cavity realizing a 4-pole dual-band filtering function is detailed. A prototype is fabricated and measured for validating the concept.

Ceramic Q-band bandpass filters by laser micro-machining of Alumina substrates

Two millimetre-wave filters (a Chebyshev 4-pole and a quasi-elliptical 6-pole 2 zeroes realized with dual-mode resonators) centred at 39 GHz are presented in this paper. They are both obtained by laser machining Alumina substrates and metallized with an electroless Copper plating technique. Laser etching is finally used again to etch the different patterns required for their input and output as well as other features. Despite the simplicity of this method, good agreements are obtained between full wave simulations and measurements, validating the proposed approach.

Additive manufacturing of microwave antennas up to 60 GHz

This paper presents three different microwave antennas made by plastic additive manufacturing. Firstly two broadband mode converters made with the Polyjet© technology are presented with their measurement. They can be used as E-plane omnidirectional antennas. The first one is designed to work in the Ka-band (measured from 28 to 36 GHz) and the second is made to work in the V-band (measured from 45 to 61 GHz). The experimental behaviour closely matches the simulated results with a realized gain contained between 6 and 8dB over the different frequencies bands. The last device is a Gaussian corrugated horn antenna designed to work over the Ka band, between 26 and 40 GHz. A first outlook of the expected performances and the fabricated prototypes are presented in this paper along.