scholarly journals A Ku-Band Magnified Active Tx/Rx Multibeam Antenna Based on a Discrete Constrained Lens

Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2824
Author(s):  
Gianfranco Ruggerini ◽  
Pasquale Giuseppe Nicolaci ◽  
Giovanni Toso
Keyword(s):  
Design Procedure ◽  
Thermal Control ◽  
Experimental Results ◽  
Frequency Bandwidth ◽  
Dual Polarization ◽  
Multibeam Antenna ◽  
Ku Band

This paper presents the design, manufacturing, and testing of a Ku-band magnified active Tx/Rx multibeam antenna based on a discrete constrained lens. Multibeam antennas based on constrained lenses generate a significant number of beams on a large operative frequency bandwidth. The main novelty and challenge in this development are associated with the combined transmitting and receiving functionality of this active array. An innovative RF building blockchain working in dual-polarization and covering both the transmitting and receiving bandwidth is successfully implemented. In order to improve the accommodation constraints and the thermal control, the active lens is magnified by two confocal paraboloidal reflectors. To validate the design procedure, experimental results are compared with numerical ones.

scholarly journals A new ZCZVT commutation cell for PWM DC-AC converters

2004 ◽  
Vol 15 (2) ◽  
pp. 162-171 ◽  
Author(s):  
C. M. de O. Stein ◽  
H. L. Hey ◽  
J. R. Pinheiro ◽  
H. Pinheiro ◽  
H. A. Gründling
Keyword(s):  
Design Procedure ◽  
Experimental Results ◽  
Cell Design ◽  
Load Range ◽  
Switching Operation ◽  
Full Load ◽  
Turn On ◽  
Zero Current ◽  
Ac Converters ◽  
Zero Voltage

This paper proposes a new auxiliary commutation cell for PWM inverters that allows the main switches to be turned on and off at zero voltage and zero current. The main switches zero current turn-on reduces the undesired effects of parasitic inductances related to the circuit layout. The main diodes reverse recovery losses are minimized since di/dt and dv/dt are controlled. The ZCZVT commutation cell is located out of the main power path of the converters and is activated only during switching transitions. Additionally, the auxiliary switches are turned on and off at ZCS and use the same ground signals of the upper main switches. The commutation losses are practically reduced to zero. Soft switching operation is guaranteed for full load range without changes in command strategy. The operation of the ZCZVT PWM full-bridge DC-AC Converter is analyzed and an auxiliary commutation cell design procedure based on the analysis is proposed. Experimental results are presented to demonstrate the feasibility of the proposed commutation cell.

scholarly journals Development of Enabling Technologies for Ku-Band Airborne SATCOM Phased-Arrays

Electronics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 488
Author(s):  
Alfredo Catalani ◽  
Giovanni Toso ◽  
Piero Angeletti ◽  
Mario Albertini ◽  
Pasquale Russo
Keyword(s):  
Phased Array ◽  
Phased Arrays ◽  
Satellite Communications ◽  
Antenna System ◽  
Array Antenna ◽  
Commercial Product ◽  
Dual Polarization ◽  
Phased Array Antenna ◽  
Radiating Element ◽  
Ku Band

In the paper the development of a fully electronic transmit-receive phased-array antenna system in Ku-band for aircraft communications via satellite is presented. Particular emphasis has been placed in the improvement of the following key elements: a dual-polarization self-diplexing radiating element, a transmit/receive active module with full polarization agility based on a digital vector modulator and a SiGe multinode MMIC. The optimized antenna elements enable a significant improvement towards the realization of a future affordable commercial product for satellite communications.

scholarly journals Design Optimisation of a Nonlinear Energy Sink Embedded on a Harmonically Forced Linear Oscillator: Theoretical and Experimental Developments

2012 ◽  
Author(s):  
Etienne Gourc ◽  
Guilhem Michon ◽  
Sébastien Seguy ◽  
Alain Berlioz
Keyword(s):  
Invariant Manifolds ◽  
Relaxation Oscillation ◽  
Design Procedure ◽  
Nonlinear Energy Sink ◽  
Experimental Results ◽  
Linear Oscillator ◽  
Mapping Procedure ◽  
Modulation Equations ◽  
Energy Sink ◽  
Nonlinear Energy

In this paper, the dynamic response of a harmonically forced Linear Oscillator (LO) strongly coupled to a Nonlinear Energy Sink (NES) is investigated theoretically and experimentally. The system studied comprises a linear oscillator subject to an imposed displacement with an embedded, purely cubic, NES. The behavior of the system is analyzed in the vicinity of 1:1 resonance. The complexification averaging technique is used to obtain modulation equations and the associated fixed points. These modulation equations are analyzed using asymptotic expansion to study the regimes related as relaxation oscillation of the slow flow called Strongly Modulated Response (SMR). The zones where SMR occur are computed using a mapping procedure. The Slow Invariant Manifolds (SIM) is used to derive a proper optimization procedure. It is shown that there exist an optimal zone in the parameter plane forcing amplitude–nonlinear stiffness, where SMR occurs without having a high amplitude detached resonance tongue. An experimental setup exhibits a strong mass asymmetry (mass ratio ≈ 1%). The cubic stiffness is realized geometrically with two linear spring that extend axially and are free to rotate. Using the previous optimized stiffness of the NES, different frequency response curves and associated zones of SMR are obtained for various forcing amplitude. Good agreement between theoretical and experimental results is observed. The reported experimental results confirm the design procedure, and the possible application of NES for vibration mitigation under periodic forcing.

Design of a highly integrated Ku-band planar broadband phased array receiver with dual polarization

2014 ◽  
Author(s):  
Marc van der Vossen ◽  
Gerard Voshaar ◽  
Chris Roeloffzen ◽  
Adriaan Hulzinga ◽  
Maikel Iven
Keyword(s):  
Phased Array ◽  
Dual Polarization ◽  
Array Receiver ◽  
Ku Band

A ku-band dual-polarization connected array of dipoles with wide-scan capability for in-flight entertainment

2012 ◽  
Author(s):  
Daniele Cavallo ◽  
Giampiero Gerini ◽  
Roland Bolt ◽  
Reindert Grooters ◽  
Duije Deurloo ◽  
...  
Keyword(s):  
Dual Polarization ◽  
Ku Band

scholarly journals Dual-polarization reflectarray in Ku-band based on two layers of dipole arrays for a transmit–receive satellite antenna with South American coverage

2018 ◽  
Vol 10 (2) ◽  
pp. 149-159 ◽  
Author(s):  
Jose A. Encinar ◽  
Rafael Florencio ◽  
Manuel Arrebola ◽  
Miguel Alejandro Salas Natera ◽  
Mariano Barba ◽  
...  
Keyword(s):  
Method Of Moments ◽  
High Performance ◽  
Spectral Domain ◽  
South American ◽  
Radiation Patterns ◽  
Dual Polarization ◽  
Satellite Antenna ◽  
Dielectric Layers ◽  
Reflectarray Antenna ◽  
Ku Band

A 1.1-m reflectarray antenna has been designed, manufactured, and tested to fulfill the requirements of a satellite antenna in Ku-band that provides South-American coverage in Tx and Rx. The reflectarray cells consist of four dipoles for each polarization in two dielectric layers, selected because of their simplicity and high performance. The dipole dimensions are optimized in all the reflectarray cells to accomplish the prescribed radiation patterns, by iteratively calling an analysis routine based on method of moments in spectral domain and local periodicity. The measured radiation patterns of the manufactured antenna have been satisfactorily compared with simulations and with a three-layer reflectarray previously designed, manufactured, and tested for the same mission.

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