Alejandro Álvarez Melcón
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View article: Efficient Integral Equation Analysis of Arbitrarily Shaped Rectangular Waveguide Discontinuities Including Conducting Objects
Efficient Integral Equation Analysis of Arbitrarily Shaped Rectangular Waveguide Discontinuities Including Conducting Objects Open
In this contribution, an Integral Equation (IE) formulation is proposed for the analysis of microwave circuits, based on the junction of two different rectangular waveguides coupled by an arbitrarily shaped zero thickness discontinuity. Th…
View article: RADES axion search results with a high-temperature superconducting cavity in an 11.7 T magnet
RADES axion search results with a high-temperature superconducting cavity in an 11.7 T magnet Open
A bstract We describe the results of a haloscope axion search performed with an 11.7 T dipole magnet at CERN. The search used a custom-made radio-frequency cavity coated with high-temperature superconducting tape. A set of 27 h of data at …
View article: Design of Rectangular Waveguide Bandpass Filters with Transmission Zeros Using High-Qu Complementary Split Ring Resonators with Irises
Design of Rectangular Waveguide Bandpass Filters with Transmission Zeros Using High-Qu Complementary Split Ring Resonators with Irises Open
This paper introduces a novel bandpass filter designed in rectangular waveguide (RW) technology using an inline structure. The main design concept involves inserting a complementary split-ring resonator (CSRR) into the RW crosssection alon…
View article: Efficient Integral Equation Analysis of 3-D Rectangular Waveguide Microwave Circuits by Using Green’s Functions Accelerated With the Ewald Method
Efficient Integral Equation Analysis of 3-D Rectangular Waveguide Microwave Circuits by Using Green’s Functions Accelerated With the Ewald Method Open
In this contribution, an electric field integral equation (EFIE) formulation is proposed, for the analysis of microwave circuits based on rectangular waveguides with an unlimited number of arbitrarily 3-D-shaped conducting elements. For th…
View article: RADES axion search results with a High-Temperature Superconducting cavity in an 11.7 T magnet
RADES axion search results with a High-Temperature Superconducting cavity in an 11.7 T magnet Open
We describe the results of a haloscope axion search performed with an 11.7 T dipole magnet at CERN. The search used a custom-made radio-frequency cavity coated with high-temperature superconducting tape. A set of 27 h of data at a resonant…
View article: A technique for the passband and stopband control of wideband band-pass substrate integrated waveguide (SIW) filters designed with elliptic stepped impedances
A technique for the passband and stopband control of wideband band-pass substrate integrated waveguide (SIW) filters designed with elliptic stepped impedances Open
In this paper, a design technique based on a stepped impedance synthesis is proposed for the first time for the passband and stopband control of band-pass filters in substrate integrated waveguide (SIW) technology. The structure of the ban…
View article: Design of Wideband Substrate Integrated Waveguide Filters With Tunable Lowpass Characteristics
Design of Wideband Substrate Integrated Waveguide Filters With Tunable Lowpass Characteristics Open
In this paper, the application of the stepped impedance synthesis technique in the design of tunable wideband substrate integrated waveguide (SIW) Chebyshev filters is explored. By employing Chebyshev transfer functions and stepped impedan…
View article: Design of Evanescent-Mode Rectangular Waveguide Inline Bandpass Filters With Transmission Zeros Using Split Ring Resonators
Design of Evanescent-Mode Rectangular Waveguide Inline Bandpass Filters With Transmission Zeros Using Split Ring Resonators Open
This paper introduces a novel bandpass filter designed in rectangular waveguide (RW) technology using an inline structure. The main design concept involves inserting a complementary split-ring resonator (CSRR) into the RW cross-section alo…
View article: A Proposal for a Low‐Frequency Axion Search in the 1–2 μ$\umu$ eV Range and Below with the BabyIAXO Magnet
A Proposal for a Low‐Frequency Axion Search in the 1–2 μ$\umu$ eV Range and Below with the BabyIAXO Magnet Open
In the near future BabyIAXO will be the most powerful axion helioscope, relying on a custom‐made magnet of two bores of 70 cm diameter and 10 m long, with a total available magnetic volume of more than 7 m 3 . In this document, it proposes…
View article: Design and Implementation of Quart-Torus Waveguide Filters for Layout Optimization Using Additive Manufacturing Techniques
Design and Implementation of Quart-Torus Waveguide Filters for Layout Optimization Using Additive Manufacturing Techniques Open
In this contribution, a novel quart-torus cavity for the design of waveguide filters is presented. A filter breadboard based on this kind of cavity is designed at Ku-band, and then fabricated using Additive Manufacturing (AM) techniques. T…
View article: Compact Wideband Groove Gap Waveguide Bandpass Filters Manufactured with Printing and CNC Milling Techniques
Compact Wideband Groove Gap Waveguide Bandpass Filters Manufactured with Printing and CNC Milling Techniques Open
This paper presents for the first time a compact wideband bandpass filter in groove gap waveguide (GGW) technology. The structure is obtained by including metallic pins along the central part of the GGW bottom plate according to an n-orde…
View article: Compact Wideband Groove Gap Waveguide Bandpass Filters Manufactured with 3D Printing and CNC Milling Techniques
Compact Wideband Groove Gap Waveguide Bandpass Filters Manufactured with 3D Printing and CNC Milling Techniques Open
This paper presents for the first time a compact wideband bandpass filter in groove gap waveguide (GGW) technology. The structure is obtained by including metallic pins along the central part of the GGW bottom plate according to an n-order…
View article: A proposal for a low-frequency axion search in the 1-2 $μ$eV range and below with the BabyIAXO magnet
A proposal for a low-frequency axion search in the 1-2 $μ$eV range and below with the BabyIAXO magnet Open
In the near future BabyIAXO will be the most powerful axion helioscope, relying on a custom-made magnet of two bores of 70 cm diameter and 10 m long, with a total available magnetic volume of more than 7 m$^3$. In this document, we propose…
View article: Efficient Calculation of the 3-D Rectangular Waveguide Green’s Functions Derivatives by the Ewald Method
Efficient Calculation of the 3-D Rectangular Waveguide Green’s Functions Derivatives by the Ewald Method Open
In this contribution, the Ewald method has efficiently
\nbeen applied to accelerate the computation of the rectangular waveguide Green’s functions derivatives. Based on previous works, we have outlined new approximation formulae that avoid…
View article: Design of evanescent mode band-pass filters based on groove gap waveguide technology
Design of evanescent mode band-pass filters based on groove gap waveguide technology Open
This paper proposes for the first time a design method of Chebyshev band-pass filters based on groove gap waveguide (GGW) technology and evanescent mode. The evanescent mode GGW section has been implemented by decreasing the width of the g…
View article: Methods and restrictions to increase the volume of resonant rectangular-section haloscopes for detecting dark matter axions
Methods and restrictions to increase the volume of resonant rectangular-section haloscopes for detecting dark matter axions Open
Haloscopes are resonant cavities that serve as detectors of dark matter axions when they are immersed in a strong static magnetic field. In order to increase the volume and improve its introduction within dipole or solenoid magnets for axi…
View article: On the Development of New Tuning and Inter-Coupling Techniques Using Ferroelectric Materials in the Detection of Dark Matter Axions
On the Development of New Tuning and Inter-Coupling Techniques Using Ferroelectric Materials in the Detection of Dark Matter Axions Open
Tuning is an essential requirement for the search of dark matter axions employing haloscopes since its mass is not known yet to the scientific community. At the present day, most haloscope tuning systems are based on mechanical devices whi…
View article: Integral equation analysis of multiport H‐plane microwave circuits by using 2D rectangular cavity Green's functions accelerated by the Ewald Method
Integral equation analysis of multiport H‐plane microwave circuits by using 2D rectangular cavity Green's functions accelerated by the Ewald Method Open
An integral equation technique for the analysis of multiport H‐plane microwave circuits composed of an unlimited number of arbitrarily shaped metallic and/or dielectric elements is proposed. The structure under study is divided into differ…
View article: Compact Wideband Groove Gap Waveguide Bandpass Filters Manufactured with Printing and CNC Milling Techniques
Compact Wideband Groove Gap Waveguide Bandpass Filters Manufactured with Printing and CNC Milling Techniques Open
This paper presents for the first time a compact wideband bandpass filter in groove gap waveguide (GGW) technology. The structure is obtained by including metallic pins along the central part of the GGW bottom plate according to an n-order…
View article: Compact Wideband Groove Gap Waveguide Bandpass Filters Manufactured with Printing and CNC Milling Techniques
Compact Wideband Groove Gap Waveguide Bandpass Filters Manufactured with Printing and CNC Milling Techniques Open
This paper presents for the first time a compact wideband bandpass filter in groove gap waveguide (GGW) technology. The structure is obtained by including metallic pins along the central part of the GGW bottom plate according to an n-orde…
View article: On the use of ferroelectric material in the detection of dark matter axions
On the use of ferroelectric material in the detection of dark matter axions Open
Tuning is an essential requirement for the search of dark matter axions employing haloscopes since its mass is not known yet to the scientific community. At the present day, most haloscope tuning systems are based on mechanical devices whi…
View article: Time-modulated Patch Antennas with Tunable and Nonreciprocal Polarization Ellipticity
Time-modulated Patch Antennas with Tunable and Nonreciprocal Polarization Ellipticity Open
In this paper, we propose and demonstrate time-modulated patch antennas able to exhibit opposite polarization ellipticity when operated in transmission or reception, effectively leading to nonreciprocal polarization responses. To this purp…
View article: Time-modulated Patch Antennas with Tunable and Nonreciprocal Polarization Ellipticity
Time-modulated Patch Antennas with Tunable and Nonreciprocal Polarization Ellipticity Open
In this paper, we propose and demonstrate time-modulated patch antennas able to exhibit opposite polarization ellipticity when operated in transmission or reception, effectively leading to nonreciprocal polarization responses. To this purp…
View article: Wide-band full-wave electromagnetic modal analysis of the coupling between dark-matter axions and photons in microwave resonators
Wide-band full-wave electromagnetic modal analysis of the coupling between dark-matter axions and photons in microwave resonators Open
The electromagnetic coupling axion–photon in a microwave cavity is revisited with the Boundary Integral-Resonant Mode Expansion (BI-RME) 3D technique. Such full-wave modal technique has been applied for the rigorous analysis of the excitat…