A5084627942- Microwave Engineering and Waveguides
- Superconducting and THz Device Technology
- Radio Frequency Integrated Circuit Design
- Radio Astronomy Observations and Technology
- Gyrotron and Vacuum Electronics Research
- Cosmology and Gravitation Theories
- Advanced Antenna and Metasurface Technologies
- Knowledge Societies in the 21st Century
- Occupational Health and Safety in Workplaces
- Geophysics and Gravity Measurements
- Acoustic Wave Resonator Technologies
- Semiconductor Lasers and Optical Devices
- Photonic and Optical Devices
- Antenna Design and Analysis
- Pulsars and Gravitational Waves Research
- Power Line Communications and Noise
- Advancements in Semiconductor Devices and Circuit Design
- Business, Innovation, and Economy
- Microwave and Dielectric Measurement Techniques
- Soil Moisture and Remote Sensing
- Sensor Technology and Measurement Systems
- Astrophysics and Cosmic Phenomena
- Silicon Carbide Semiconductor Technologies
- Electromagnetic Compatibility and Noise Suppression
- Advanced Frequency and Time Standards
Universidad de Cantabria
2014-2024
University of Rome Tor Vergata
2019
The QUIJOTE (Q-U-I JOint Tenerife) CMB Experiment will operate at the Teide Observatory with aim of characterizing polarisation and other processes Galactic extragalactic emission in frequency range 10-40GHz large medium angular scales. first two telescopes multi-frequency (10-30GHz) instrument are already built have been tested laboratory. QUIJOTE-CMB be a valuable complement low frequencies for Planck mission, required sensitivity to detect primordial gravitational-wave component if...
A 64% instantaneous bandwidth scalable turnstile-based orthomode transducer to be used in the so-called extended C-band satellite link is presented. The proposed structure overcomes current practical limitations by adding a single-step widening at junction of four output rectangular waveguides. This judicious modification, together with use reduced-height waveguides and E-plane bends power combiners, enables approach theoretical limit simple, compact design. presented architecture exhibits...
A 45% bandwidth in-line air-filled waveguide-to-substrate integrated waveguide (SIW) direct transition is designed to greatly improve the performance of existing configurations. The transition, based on a four-section height-stepped waveguide, includes single-step widening transformer that enables full-band operation without using any dielectric probe. absence probe reduces significantly insertion loss and makes this simple, controllable easily scalable millimeter-wave frequency range....
A 20-dB chip attenuator designed for cryogenic noise measurements from dc up to 40 GHz is presented. The based on the use of temperature-stable tantalum-nitride thin-film resistors, a high thermal conductivity substrate such as crystal quartz (z-cut), and suitable design that avoids inner conductor heating, which an important limiting factor precision measurements. high-accuracy temperature sensor installed inside module provides precise characterization close location. in assures negligible...
This article introduces an easy and accurate technique for the full characterization of septum polarizers (SPs) in back-to-back configuration through standard amplitude/power measurements at rectangular waveguide ports. The proposed calibration algorithm, based on use two simple sections, along with developed mathematical formulation, allows complete extraction relevant SP parameters: return loss, isolation, cross-coupling (XP) or axial ratio (AR), copolarization losses (CP). methodology has...
The design and fabrication of an Ultra broadband square quad-ridge polarizer is discussed here. principal advantages this topology relay on both the instantaneous bandwidth axial ratio improvement. Experimental measurements exhibit very good agreement with predicted results given by Mode Matching techniques. structure provides extremely flat (AR< 0.4dB) return losses >25dB at ports over extended Ku band (= 60%). Moreover, yield analysis scaling properties demonstrate robustness against tolerances.
A >40% bandwidth fully scalable turnstile-based waveguide orthomode transducer having excellent phase performance is described for the WR75 standard rectangular waveguide. Flexible tuning achieved through use of an interchangeable stepped scattering element. Reduced height topology provides a simple, compact, and robust design against mechanical tolerances. The intrinsic broadband nature half-height E-plane bends single-step power combiners assures high order mode free increased in balanced...
An octave bandwidth concept for compact rectangular-to-circular and square-to-circular waveguide transitions based on the use of intermediate octagonal-shaped sections is presented. Apart from its inherent capability spurious mode free operation, this architecture offers some other useful advantages such as easy fabrication, low losses, extremely short length (less than 0.75 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> , with being...
The QUIJOTE-CMB project has been described in previous publications.Here we present the current status of QUIJOTE multi-frequency instrument (MFI) with five separate polarimeters (providing 5 independent sky pixels): two which operate at 10-14 GHz, 16-20 and a central polarimeter 30 GHz.The optical arrangement includes conical corrugated feedhorns staring into dual reflector crossed-draconian system, provides optimal cross-polarization properties (designed to be < -35 dB) symmetric...
A highly compact and efficient dual-mode power divider suitable for multi-level (4 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</sup> ) beam-forming networks is presented. Circular waveguide dual polarization accomplished by using a symmetric 4:1 turnstile-like topology strategic cavity resonance suppressors to achieve more than 20% bandwidth operation with theoretical 35 dB cross-polar discrimination. Experimental verification Ku-band...
This work proposes an easily scalable quadrature hybrid coupler (QHC) topology with two symmetric stepped apertures that originate a square coaxial-like mid-section. new configuration enables ultra-compact design, three times shorter than equivalent structures, having 40% of fractional bandwidth 25 dB matching/isolation and 1 axial ratio (AR). The impedance transformers can be redesigned to meet other requirements related electrical performance or even desired coupling values. For...
This paper presents the analysis, design, and characterization of thirty gigahertz instrument receiver developed for Q-U-I Joint Tenerife experiment. The is aimed to obtain polarization data cosmic microwave background radiation from sky, obtaining Q, U, I Stokes parameters incoming signal simultaneously. A comprehensive analysis theory behind proposed presented a linearly polarized input signal, functionality tests have demonstrated adequate results in terms parameters, which validate...
A very low‐loss in‐line rectangular waveguide‐to‐coaxial transition covering an octave bandwidth is presented. In order to obtain such frequency coverage, the employs oversized mode conversion, i.e. waveguide dimensions are internally enlarged modify cavity cutoff while obtaining good matching properties for a standard output port. four‐step ridge transformer included TE‐to‐TE 10 conversion in whole range. The transition, completed with commercial SMA connector coaxial port, exhibits return...
A wideband (30% relative bandwidth) correlation and detection module based on substrate-integrated waveguide (SIW) technology intended for a radio astronomy polarimeter is presented. The SIW circuit six-port network with two input ports that are correlated in hybrid couplers their corresponding output signals routed to Schottky diode detectors, which designed using microstrip assembled within the same system. structure includes couplers, power dividers, 90° phase shifter, bends, providing...
QUIJOTE (Q-U-I JOint TEnerife) is a new polarimeter aimed to characterize the polarization of Cosmic Microwave Background and other Galactic extragalactic signals at medium large angular scales in frequency range 10-40 GHz. The multi-frequency (10-20~GHz) instrument, mounted on first telescope, saw light November 2012 from Teide Observatory (2400~m a.s.l). During 2014 second telescope has been installed this observatory. A instrument 30~GHz will be ready for commissioning during summer 2015,...
Differential phase shifters are common circuits in communication systems where a fixed difference between two points within the circuit is required. Among available technologies, waveguide preferred for applications such as antenna feed or beam-forming networks. Typical designs literature devoted to specific delays 90° 180°, but any shift might be required, and therefore design procedure resulting mechanically-related parameter fitting equations arbitrary would advantageous. This paper...
A 64% instantaneous bandwidth turnstile-junction-based orthomode transducer (OMT) made up of only three layers in a platelet configuration is presented. Such frequency coverage, while maintaining very much reduced number layers, accomplished mainly by incorporating an improved power combiner based on noncontacting matching steps machined one layer. This solution makes real impact the compactness concept these OMTs excellent electrical performance. An OMT 10-20-GHz band was designed and...
The QUIJOTE (Q-U-I JOint Tenerife) CMB Experiment is designed to observe the polarization of Cosmic Microwave Background and other Galactic extragalactic signals at medium large angular scales in frequency range 10-40 GHz. first two telescopes multi-frequency (10-20 GHz) instrument have been operation since November 2012. In 2014 a second telescope new 30GHz will be ready for commissioning, an additional 40 GHz its final design stages. After three years effective observations, data obtained...
This paper demonstrates the feasibility of very compact and broadband square waveguide bends able to transmit both linear circular polarizations. A careful control bend profile for dual-linear polarization or use a new septum-polarizer-like geometry dual-circular allows reach full band operation ~34% in first case ~20% second application. Experimental validations show excellent agreement with theoretical predictions thus effectively extending previous bandwidth limitations.
Abstract Substrate integrated circuits (SIC) have attracted much attention in the last years because of their great potential low cost, easy manufacturing, integration a circuit board, and higher‐quality factor than planar circuits. A first suite SIC where waves propagate through dielectric been developed, based on well‐known substrate waveguide (SIW) related technological implementations. One step further has made with new empty waveguides, air, thus reducing associated losses. This is case...
QUIJOTE (Q-U-I JOint TEnerife) is an experiment designed to achieve CMB B-mode polarization detection and sensitive enough detect a primordial gravitational-wave component if the amplitude larger than r = 0.05. It consists in two telescopes three instruments observing frequency range 10-42 GHz installed at Teide Observatory Canary Islands, Spain. The strategy includes raster scan deep integration fields for cosmology, nominal wide survey covering Northen Sky specific observations regions of...
The architecture concept and fabrication of a quasi-octave bandwidth waveguide feed network for circular polarized antennas is discussed here. main advantages this extremely compact topology rely on three key achievements: the instantaneous capability, axial ratio improvement significant size reduction which in many cases determinant antenna subsystems. Experimental measurements exhibit very good agreement with predicted results given by conventional mode matching techniques. overall...
This paper presents the design, simulation and measurement of a broadband Back-End Module (BEM) for radio-astronomy applications in Ka-band. It is direct conversion receiver based on low noise amplification, band pass filtering Schottky diode detection. System simulations are individual linear-subsystems S-parameters measurements together with non-linear detector model. Measurements show more than 30 dB RF gain over 26 to 36 GHz figure below 3.9 dB. Detected voltage range 1-10 mV which meets...