9 research outputs found
Design of controlled RF switch for beam steering antenna array
YesA printed dipole antenna integrated with a duplex RF switch used for mobile base
station antenna beam steering is presented. A coplanar waveguide to coplanar strip transition was adopted to feed the printed dipole. A novel RF switch circuit, used to control the RF signal fed to the dipole antenna and placed directly before the dipole, was proposed. Simulated and
measured data for the CWP-to-CPS balun as well as the measured performance of the RF switch are shown. It has demonstrated the switch capability to control the beam in the design of beam steering antenna array for mobile base station applications
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Beam Steering of Time Modulated Antenna Arrays Using Particle Swarm Optimization
yesIn this paper, a simple switching process is employed to steer the beam of a vertically polarised circular antenna array. This is a simple method, in which the difference resulting from the induced currents when the radiating/loaded element is connected/disconnected from the ground plane. A time modulated switching process is applied through particle swarm optimisation.Electronics and Telecommunication
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Frequency Tuned Planar Inverted F Antenna with L Shaped Slit Design for Wide Frequency Range.
yesA frequency tuned antenna has been designed to meet the coverage requirements of the DCS, PCS, UMTS and WLAN bands. The antenna consists of a main patch, and a planar inverted L (PIL) slot. The radiator patch is fed, and shorted, using simple feed lines with broadband characteristics. The handset represents the finite ground plane, and a varactor diode is mounted across the middle of the slot for tuning purposes. Initial tuning was obtained by placing lumped capacitors, instead of the varactor, over the radiator. Good agreement is obtained between the predicted and measured input return loss, gain and radiation pattern over the tuned frequency range.MSCR
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Design and modelling of beam steering antenna array for mobile and wireless applications using optimisation algorithms. Simulation and measrement of switch and phase shifter for beam steering antenna array by applying reactive loading and time modulated switching techniques, optimised using genetic algorithms and particle swarm methods.
The objectives of this work were to investigate, design and implement beam steering antenna arrays for
mobile and wireless applications using the genetic algorithm (GA) and particle swarm optimisation (PSO)
techniques as optimisation design tools. Several antenna designs were implemented and tested: initially, a
printed dipole antenna integrated with a duplex RF switch used for mobile base station antenna beam
steering was investigated. A coplanar waveguide (CPW) to coplanar strip (CPS) transition was adopted to
feed the printed dipole. A novel RF switch circuit, used to control the RF signal fed to the dipole antenna
and placed directly before it, was proposed. The measured performance of the RF switch was tested and
the results confirmed its viability. Then two hybrid coupled PIN diode phase shifters, using Branchline
and Rat-Race ring coupler structures, were designed and tested. The generation of four distinct phase
shifts was implemented and studied. The variations of the scattering parameters were found to be realistic,
with an acceptable ±2 phase shift tolerance.
Next, antenna beam steering was achieved by implementing RF switches with ON or OFF mode
functions to excite the radiating elements of the antenna array. The switching control process was
implemented using a genetic algorithm (GA) method, subject to scalar and binary genes. Anti-phase
feeding of radiating elements was also investigated. A ring antenna array with reflectors was modelled
and analysed. An antenna of this type for mobile base stations was designed and simulation results are
presented.
Following this, a novel concept for simple beam steering using a uniform antenna array operated at 2.4
GHz was designed using GA. The antenna is fed by a single RF input source and the steering elements
are reactively tuned by varactor diodes in series with small inductors. The beam-control procedure was
derived through the use of a genetic algorithm based on adjusting the required reactance values to obtain
the optimum solution as indicated by the cost function. The GA was also initially used as an optimisation
tool to derive the antenna design from its specification.
Finally, reactive loading and time modulated switching techniques are applied to steer the beam of a
circular uniformly spaced antenna array having a source element at its centre. Genetic algorithm (GA)
and particle swarm optimisation (PSO) processes calculate the optimal values of reactances loading the
parasitic elements, for which the gain can be optimised in a desired direction. For time modulated
switching, GA and PSO also determine the optimal on and off times of the parasitic elements for which
the difference in currents induced optimises the gain and steering of the beam in a desired direction.
These methods were demonstrated by investigating a vertically polarised antenna configuration. A
prototype antenna was constructed and experimental results compared with the simulations. Results
showed that near optimal solutions for gain optimisation, sidelobe level reduction and beam steering are
achievable by utilising these methods. In addition, a simple switching process is employed to steer the
beam of a horizontally polarised circular antenna array. A time modulated switching process is applied
through Genetic Algorithm optimisation. Several model examples illustrate the radiation beams and the
switching time process of each element in the array
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Modified small PIFA frequency tunable antenna,
NoThis paper presents a physically compact, frequency tunable antenna design for use in mobile terminals. The full operating bandwidth is between 1750 MHz and 2400 MHz with good impedance match in the entire tuning range to meet the coverage requirements of the DCS, PCS, UMTS and WLAN bands . The antenna bandwidth is is realized by loading the embedded resonant slot of a PIFA, with a varactor diode, with an equivalent capacitance range of 0.5 pF to 2.5 pF
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Time modulated switching and reactive loading techniques applied to a circular array antenna using genetic algorithm optimisation
NoAdaptive arrays have the capability to direct or steer the main beam in real time in a desired direction, or towards signal of interest (SOI), whilst suppressing interference or multipath signals. Reactive loading and time modulated switching techniques are applied to steer the beam of a uniform circular six element antenna array having a source element at its centre. Genetic algorithm (GA) optimization is used to calculate optimal values for the reactances loading the parasitic elements, from which the gain can be optimized in a desired direction. For temporal switching, the GA is also used to determine the optimal on and off times for the parasitic elements. This gives the difference in the induced currents, optimies the gain and steers the beam in a desired direction. These methods are demonstrated for a vertically polarised array configuration operating at 2.45GHz. Simulation results show that near optimal solutions for gain, sidelobe level reduction, with VSWR 3 over a 100MHz bandwidth, and beam steering is achievable by the GA optimisation
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Beam steering technique for binary switched array antenna using genetic algorithm
NoA new approach in achieving beam steering in array antenna is introduced using the genetic algorithm optimization. The binary switching technique uses simple binary ON/OFF diodes placed in the feeding network of the array element to achieve beam steering. Constantly feeding the driven element and continuous binary variation of the ON/OFF state of each parasitic array elements which determines its conducting ability defines a beam steering angle. Each beam steered angle is distinguished by series of binary combination determined by the genetic algorithm. A uniform circular array antenna consisting of 13 elements is used to implement this technique. The simulation and result analysis of the binary switched array is presented with several beam steering angles scanned