Santi Pavone | University of Siena / Università di Siena (original) (raw)
Papers by Santi Pavone
—The paper presents the analysis and design of Bessel beam launchers using a finite inward cylind... more —The paper presents the analysis and design of Bessel beam launchers using a finite inward cylindrical traveling wave aperture field distribution. The launcher radiates an electric field whose normal or longitudinal component takes the form of a zeroth-order Bessel function. The nondiffractive behavior of the structure in a well-defined area close to the radiating aperture is analyzed by decomposing the radiated field in its geometrical optics (GO) and diffractive (D) contributions. A closed-form expression is provided for the GO contribution whereas an asymp-totic approximation is provided for the diffractive part. Such theoretical analysis allows a precise definition of the nondiffrac-tive region for the generated Bessel beam. At the same time, it also highlights and predicts the oscillating behavior of the longitudinal component of the electric field along the z-axis due to the diffraction from the edges of the aperture. The proposed analysis is validated by a prototype at 30 GHz made by a radial waveguide loaded with metallic gratings and centrally fed by a coaxial probe. Measurement results for the longitudinal component of the electric field are in excellent agreement with full-wave results. In addition , the nondiffractive behavior for the radiated beam is reported over a bandwidth larger than 6.5% around 30 GHz. This behavior is peculiar of the nonresonant first kind Hankel aperture field distribution used for the generation of the Bessel beam.
In this paper the focusing capability of a radiating aperture implementing an inward cylindrical ... more In this paper the focusing capability of a radiating aperture implementing an inward cylindrical traveling wave tangential electric field distribution directed along a fixed polarization unit vector is investigated. In particular, it is shown that such an aperture distribution generates a non-diffractive Bessel beam whose transverse component (with respect to the normal of the radiating aperture) of the electric field takes the form of a zero-th order Bessel function. As a practical implementation of the theoretical analysis, a circular-polarized Bessel beam launcher, made by a radial parallel plate waveguide loaded with several slot pairs, arranged on a spiral pattern, is designed and optimized. The proposed launcher performance agrees with the theoretical model and exhibits an excellent polarization purity.
The 8th European Conference on Antennas and Propagation (EuCAP 2014), 2014
2014 IEEE Antennas and Propagation Society International Symposium (APSURSI), 2014
ABSTRACT We present an automatically optimized near-field focusing radial line slot array (RLSA) ... more ABSTRACT We present an automatically optimized near-field focusing radial line slot array (RLSA) antenna. The side lobe level and beamwidth of the normal component of the radiated electric field are controlled during the design process. A set theoretic approach is used to derive the RLSA aperture field distribution generating the required near field over a focusing plane at a given distance from the radiating aperture. The position and size of the slots of the RLSA antenna are automatically controlled to synthesize the derived aperture field distribution. The design approach is validated by measurements at 12.5 GHz.
2014 USNC-URSI Radio Science Meeting (Joint with AP-S Symposium), 2014
Optics express, Jan 28, 2014
The focusing capabilities of an inward cylindrical traveling wave aperture distribution and the n... more The focusing capabilities of an inward cylindrical traveling wave aperture distribution and the non-diffractive behaviour of its radiated field are analyzed. The wave dynamics of the infinite aperture radiated field is clearly unveiled by means of closed form expressions, based on incomplete Hankel functions, and their ray interpretation. The non-diffractive behaviour is also confirmed for finite apertures up to a defined limited range. A radial waveguide made by metallic gratings over a ground plane and fed by a coaxial feed is used to validate numerically the analytical results. The proposed system and accurate analysis of non-diffractive Bessel beams launched by inward waves opens new opportunities for planar, low profile beam generators at microwaves, Terahertz and optics.
IEEE Transactions on Antennas and Propagation, 2015
ABSTRACT In this paper we prove experimentally that nondiffractive Bessel beams can be generated ... more ABSTRACT In this paper we prove experimentally that nondiffractive Bessel beams can be generated by using inward cylindrical traveling wave aperture distributions. An azimuthally invariant inward traveling wave distribution is defined over the aperture of a Radial Line Slot Array (RLSA) to launch a Bessel beam whose normal electric-field component assumes a truncated, zeroth-order Bessel function. An optimization procedure based on a holographic approach is used for tuning the position and size of the slots of the RLSA. The antenna is centrally fed by a coaxial probe transition. The final structure operates at 12.5 GHz. Full-wave simulations and measurements of the vertical component of the electric field show that a non-diffractive radiation is obtained within a range larger than 12 wavelengths in front of the antenna. The generated Bessel beam presents a stable half power beamwidth of about 20 mm within this range. The proposed system may open new opportunities for planar, low profile Bessel beam generators at millimeter waves, Terahertz, and optics.
Optics express, Jan 28, 2014
The focusing capabilities of an inward cylindrical traveling wave aperture distribution and the n... more The focusing capabilities of an inward cylindrical traveling wave aperture distribution and the non-diffractive behaviour of its radiated field are analyzed. The wave dynamics of the infinite aperture radiated field is clearly unveiled by means of closed form expressions, based on incomplete Hankel functions, and their ray interpretation. The non-diffractive behaviour is also confirmed for finite apertures up to a defined limited range. A radial waveguide made by metallic gratings over a ground plane and fed by a coaxial feed is used to validate numerically the analytical results. The proposed system and accurate analysis of non-diffractive Bessel beams launched by inward waves opens new opportunities for planar, low profile beam generators at microwaves, Terahertz and optics.
2014 IEEE Antennas and Propagation Society International Symposium (APSURSI), 2014
ABSTRACT We present an automatically optimized near-field focusing radial line slot array (RLSA) ... more ABSTRACT We present an automatically optimized near-field focusing radial line slot array (RLSA) antenna. The side lobe level and beamwidth of the normal component of the radiated electric field are controlled during the design process. A set theoretic approach is used to derive the RLSA aperture field distribution generating the required near field over a focusing plane at a given distance from the radiating aperture. The position and size of the slots of the RLSA antenna are automatically controlled to synthesize the derived aperture field distribution. The design approach is validated by measurements at 12.5 GHz.
IEEE Transactions on Antennas and Propagation, 2000
We describe the design of a radial line slot array antenna with a shaped and focused near field. ... more We describe the design of a radial line slot array antenna with a shaped and focused near field. The antenna is designed in such a way to control the side lobe level and beamwidth of the normal component of the electric field with respect to the radiating aperture. The design procedure consists of two steps. In the first step, the requirements on the near-field pattern are provided over a focusing plane at a given distance from the radiating aperture. A set theoretic approach is then used to derive the aperture field distribution fitting the requirements over the near field. In the second step, the aperture field distribution is synthesized by accurately placing and sizing the slots of the antenna. The spillover efficiency is maximized during the design process. The antenna is centrally fed by a simple coaxial probe. The antenna design is validated by a prototype and measurements at 12.5 GHz.
The 8th European Conference on Antennas and Propagation (EuCAP 2014), 2014
—The paper presents the analysis and design of Bessel beam launchers using a finite inward cylind... more —The paper presents the analysis and design of Bessel beam launchers using a finite inward cylindrical traveling wave aperture field distribution. The launcher radiates an electric field whose normal or longitudinal component takes the form of a zeroth-order Bessel function. The nondiffractive behavior of the structure in a well-defined area close to the radiating aperture is analyzed by decomposing the radiated field in its geometrical optics (GO) and diffractive (D) contributions. A closed-form expression is provided for the GO contribution whereas an asymp-totic approximation is provided for the diffractive part. Such theoretical analysis allows a precise definition of the nondiffrac-tive region for the generated Bessel beam. At the same time, it also highlights and predicts the oscillating behavior of the longitudinal component of the electric field along the z-axis due to the diffraction from the edges of the aperture. The proposed analysis is validated by a prototype at 30 GHz made by a radial waveguide loaded with metallic gratings and centrally fed by a coaxial probe. Measurement results for the longitudinal component of the electric field are in excellent agreement with full-wave results. In addition , the nondiffractive behavior for the radiated beam is reported over a bandwidth larger than 6.5% around 30 GHz. This behavior is peculiar of the nonresonant first kind Hankel aperture field distribution used for the generation of the Bessel beam.
In this paper the focusing capability of a radiating aperture implementing an inward cylindrical ... more In this paper the focusing capability of a radiating aperture implementing an inward cylindrical traveling wave tangential electric field distribution directed along a fixed polarization unit vector is investigated. In particular, it is shown that such an aperture distribution generates a non-diffractive Bessel beam whose transverse component (with respect to the normal of the radiating aperture) of the electric field takes the form of a zero-th order Bessel function. As a practical implementation of the theoretical analysis, a circular-polarized Bessel beam launcher, made by a radial parallel plate waveguide loaded with several slot pairs, arranged on a spiral pattern, is designed and optimized. The proposed launcher performance agrees with the theoretical model and exhibits an excellent polarization purity.
The 8th European Conference on Antennas and Propagation (EuCAP 2014), 2014
2014 IEEE Antennas and Propagation Society International Symposium (APSURSI), 2014
ABSTRACT We present an automatically optimized near-field focusing radial line slot array (RLSA) ... more ABSTRACT We present an automatically optimized near-field focusing radial line slot array (RLSA) antenna. The side lobe level and beamwidth of the normal component of the radiated electric field are controlled during the design process. A set theoretic approach is used to derive the RLSA aperture field distribution generating the required near field over a focusing plane at a given distance from the radiating aperture. The position and size of the slots of the RLSA antenna are automatically controlled to synthesize the derived aperture field distribution. The design approach is validated by measurements at 12.5 GHz.
2014 USNC-URSI Radio Science Meeting (Joint with AP-S Symposium), 2014
Optics express, Jan 28, 2014
The focusing capabilities of an inward cylindrical traveling wave aperture distribution and the n... more The focusing capabilities of an inward cylindrical traveling wave aperture distribution and the non-diffractive behaviour of its radiated field are analyzed. The wave dynamics of the infinite aperture radiated field is clearly unveiled by means of closed form expressions, based on incomplete Hankel functions, and their ray interpretation. The non-diffractive behaviour is also confirmed for finite apertures up to a defined limited range. A radial waveguide made by metallic gratings over a ground plane and fed by a coaxial feed is used to validate numerically the analytical results. The proposed system and accurate analysis of non-diffractive Bessel beams launched by inward waves opens new opportunities for planar, low profile beam generators at microwaves, Terahertz and optics.
IEEE Transactions on Antennas and Propagation, 2015
ABSTRACT In this paper we prove experimentally that nondiffractive Bessel beams can be generated ... more ABSTRACT In this paper we prove experimentally that nondiffractive Bessel beams can be generated by using inward cylindrical traveling wave aperture distributions. An azimuthally invariant inward traveling wave distribution is defined over the aperture of a Radial Line Slot Array (RLSA) to launch a Bessel beam whose normal electric-field component assumes a truncated, zeroth-order Bessel function. An optimization procedure based on a holographic approach is used for tuning the position and size of the slots of the RLSA. The antenna is centrally fed by a coaxial probe transition. The final structure operates at 12.5 GHz. Full-wave simulations and measurements of the vertical component of the electric field show that a non-diffractive radiation is obtained within a range larger than 12 wavelengths in front of the antenna. The generated Bessel beam presents a stable half power beamwidth of about 20 mm within this range. The proposed system may open new opportunities for planar, low profile Bessel beam generators at millimeter waves, Terahertz, and optics.
Optics express, Jan 28, 2014
The focusing capabilities of an inward cylindrical traveling wave aperture distribution and the n... more The focusing capabilities of an inward cylindrical traveling wave aperture distribution and the non-diffractive behaviour of its radiated field are analyzed. The wave dynamics of the infinite aperture radiated field is clearly unveiled by means of closed form expressions, based on incomplete Hankel functions, and their ray interpretation. The non-diffractive behaviour is also confirmed for finite apertures up to a defined limited range. A radial waveguide made by metallic gratings over a ground plane and fed by a coaxial feed is used to validate numerically the analytical results. The proposed system and accurate analysis of non-diffractive Bessel beams launched by inward waves opens new opportunities for planar, low profile beam generators at microwaves, Terahertz and optics.
2014 IEEE Antennas and Propagation Society International Symposium (APSURSI), 2014
ABSTRACT We present an automatically optimized near-field focusing radial line slot array (RLSA) ... more ABSTRACT We present an automatically optimized near-field focusing radial line slot array (RLSA) antenna. The side lobe level and beamwidth of the normal component of the radiated electric field are controlled during the design process. A set theoretic approach is used to derive the RLSA aperture field distribution generating the required near field over a focusing plane at a given distance from the radiating aperture. The position and size of the slots of the RLSA antenna are automatically controlled to synthesize the derived aperture field distribution. The design approach is validated by measurements at 12.5 GHz.
IEEE Transactions on Antennas and Propagation, 2000
We describe the design of a radial line slot array antenna with a shaped and focused near field. ... more We describe the design of a radial line slot array antenna with a shaped and focused near field. The antenna is designed in such a way to control the side lobe level and beamwidth of the normal component of the electric field with respect to the radiating aperture. The design procedure consists of two steps. In the first step, the requirements on the near-field pattern are provided over a focusing plane at a given distance from the radiating aperture. A set theoretic approach is then used to derive the aperture field distribution fitting the requirements over the near field. In the second step, the aperture field distribution is synthesized by accurately placing and sizing the slots of the antenna. The spillover efficiency is maximized during the design process. The antenna is centrally fed by a simple coaxial probe. The antenna design is validated by a prototype and measurements at 12.5 GHz.
The 8th European Conference on Antennas and Propagation (EuCAP 2014), 2014