Patents on reconfigurable reflectarray antennas (original) (raw)
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JOURNAL OF HIGH-FREQUENCY COMMUNICATION TECHNOLOGIES
The frequency reconfigurable reflectarray (RRA) reported in this paper provides a pencil beam at three frequencies captivating the need for satellite broadcast television at uplink and downlink frequencies in Ku band and X band. To achieve such frequency reconfiguration, a unit cell developed and simulated based on an infinite array approach is used in integration with four PIN diodes to produce a reflection phase variation of 525°, 415°, and 308° at 14.34 GHz for uplink operation, 12.2 GHz for downlink and 11.9 GHz for X-band performance respectively. In this proposed unit cell, the phase variation for uplink is achieved by varying the size of concentric loops, while in the case of downlink and X-band, reconfiguration controlled by pin diodes is achieved by varying the length of the delay line. With the periodicity of 0.49λ0 (10.5 mm), a 15 15 array with 225 elements is constructed using the designed unit cell on square planar geometry. The paper reports a maximum gain of 25.77 dBi...
Global technique analysis for reconfigurable reflectarray antennas
This paper focuses on the simulation of reconfigurable reflectarrays. A new method combining the 'surrounded-cell' approach and the compression method is presented. The method considers the real environment of the radiated elements and it only requires one lightweight electromagnetic simulation for the whole reflectarray.
Phase Characterization of Reconfigurable Reflectarray Antennas
International Journal on Electrical Engineering and Informatics, 2013
The design and performance optimization of X-band reconfigurable reflectarray antennas have been discussed in this paper concentrating mainly on the phase characteristics. Liquid crystals based substrates and slot embedded patch elements have been proposed as two different techniques for the design of reflectarrays with frequency tunability characteristics. Reflectarray patch elements constructed on anisotropic liquid crystal substrate are proposed to be employed as a dynamic phase control strategy for terrestrial systems. A detailed analysis of dynamic phase range and frequency tunability with respect to dielectric anisotropy is presented for two different anisotropic liquid crystal substrate materials. The investigated liquid crystals substrates provided a maximum reduction of 14.1% in volume for reflectarray design at 10 GHz. Moreover rectangular slots on the patch elements are shown to offer a maximum frequency tenability of 1.7GHz. The Finite Integral Method (FIM) validated by waveguide scattering parameter measurements demonstrated a dynamic phase range of 314° and a volume reduction of up to 24.36%.
Design of a reconfigurable reflectarray based on a varactor tuned element
2012 6th European Conference on Antennas and Propagation (EUCAP), 2012
The design of a single varactor-based reconfigurable reflectarray is presented which adopts an aperture-coupled single-element configuration. A planar array prototype of 3x15 radiators is considered as validation example of the proposed structure. A DAC-board is integrated to the reflectarray antenna for driving the varactor bias voltages. Measured radiation patterns are reported to demonstrate the beam-scanning capabilities of the designed reflectarray prototype.
A 1-Bit 10×10 Reconfigurable Reflectarray
An electronically reconfigurable reflectarray antenna (RRA) with 10×10 elements is presented with a detailed design procedure for an improved beam-scanning performance. The element, designed at Ku band using a simple patch structure with one PIN diode and two substrate layers, can be electronically controlled to generate two states with 180º phase difference and low reflection loss. A reflectarray prototype is fabricated and experimentally studied for proof of principle. The limitations of the small aperture size are analyzed in details, and synthetic optimizations of both feed location and aperture phase distribution are used to improve the beam scanning performance of the prototype. Experimental results agree well with full-wave simulations, and scan beams within ±50º range are obtained with a maximum aperture efficiency of 17.9% at 12.5 GHz. Consistent scan beams are obtained from 11.75 GHz to 13.25 GHz.
Active reconfigurable reflectarray based on voltage-controlled oscillators
2010
A reconfigurable reflectarray based on the use of voltage controlled oscillators is presented. Each of the cells in the reflectarray is formed by an active oscillator antenna consisting of a radiating element aperture coupled to a voltage-controlled oscillator (VCO). The various cells due to radiation coupling form a coupled oscillator array. Beam-steering as well as beam forming can be achieved by appropriately tuning the free-running frequency of the individual oscillators. After the desired beam pattern is synthesized, modulation is introduced to the array by synchronizing each individual cell to the feeding horn signal in a star topology. The proposed system allows a continuous and electronic control of the reflected wave phase. Harmonic balance continuation methods combined with EM simulation are used to design the array. A 2x4 prototype at 6.1 GHz has been designed, implemented and tested.
Wireless Communications and Mobile Computing, 2021
This work presents the design and analysis of active reflectarray antennas with slot embedded patch element configurations within an X -band frequency range. Two active reflectarray design technologies have been proposed by digital frequency switching using PIN diodes and analogue frequency tuning using liquid crystal-based substrates. A waveguide simulator has been used to perform scattering parameter measurements in order to practically compare the performance of reflectarray designed based on the two active design technologies. PIN diode-based active reflectarray unit cell design is shown to offer a frequency tunability of 0.36 GHz with a dynamic phase range of 226°. On the other hand, liquid crystal-based design provided slightly lower frequency tunability of 0.20 GHz with a dynamic phase range of 124°. Moreover, the higher reflection loss and slow frequency tuning are demonstrated to be the disadvantages of liquid crystal-based designs as compared to PIN diode-based active refl...
Characterization of resonant elements for passive and reconfigurable reflectarray design
2014 5th International Conference on Intelligent and Advanced Systems (ICIAS), 2014
The performance of individual reflectarray resonant elements drives the overall performance of the reflectarray antenna. This work proposes novel configurations of reflectarray unit cells with different slot configurations embedded on the patch elements. A detailed theoretical analysis on the scattering energy is provided for the reflectarray antenna design. The proposed designs are categorized based on the capability of frequency tunability and dynamic phase range obtained by varying the dimensions of the slots on the patch elements. Measured and simulated results demonstrate a very close agreement where rectangular slots provide a measured frequency tunability of 1.68 GHz and dynamic phase range of 332° at 9.66 GHz while the design with circular slots provides a measured frequency tunability of 1.46 GHz and dynamic phase range of 330° at 10.27 GHz.
Design and Development of Frequency Agile Reflectarray Antenna
JOURNAL OF HIGH-FREQUENCY COMMUNICATION TECHNOLOGIES
This paper presents the design of a frequency reconfigurable reflectarray with concentric circular rings. The PIN diode connected between a phase delay line and the ring produces reconfigured resonances at 16 GHz and 10.4 GHz. The variation in the size of the concentric rings offer a phase change of 356º during the OFF state of the PIN diode. 360° phase variation in the PIN ON condition is achieved by varying the delay line length. A 225-element centre-fed reflectarray antenna is constructed with square geometry. A simulated gain of 23 dBi is obtained with -17 dB side lobe level and -28 dB cross-polarization level at 16 GHz. In the PIN ON condition, a simulated gain of 22 dBi is obtained with -12 dB side lobe level and -28 dB cross polarization level. This reconfigurable reflectarray finds its applications in space research, satellite communication, and RADAR.