Beam Switching Capability Research Articles

Switch beam dielectric resonator antenna array with four reconfigurable radiation patterns

A single feed, four element dielectric resonator antenna (DRA) array with beam switching capability is proposed. A wide impedance bandwidth of 700 MHz (1.6–2.3 GHz) is achieved. The proposed array is designed to operate in four modes, each mode having diverse radiation pattern. The beam is switched in azimuth (θ = 45°) at Φ = 0°, 90°, 180°, and 270°. The antenna gain is found to be more than 5 dB in most of the frequency band of interest. The reflection coefficient and radiation characteristics of proposed switched beam DRA array are investigated and validated by measurements. A good agreement between the measured and simulated results is observed. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:86–92, 2016

Design of phased array antennas with beam switching capability in the near‐field focus applications

This study presents the design methodology of a phased array antenna whose radiation will focus in the near zone of array aperture by using microstrip feeding circuits. A beam-forming network based on Butler matrix is also implemented to scan the radiation beam along a target area in the near zone, which may improve the energy efficiency and reduce the multipath interferences. The design approach, numerical simulation and experimental measurement over an antenna prototype in the applications of radio-frequency identification are presented to validate the feasibility.

A COMPACT BEAM RECONFIGURABLE ANTENNA FOR SYMMETRIC BEAM SWITCHING

In this paper, two radiation pattern-reconflgurable antennas are designed to operate near the frequency of 1.8GHz. The geometry of the proposed antennas is symmetric with respect to the vertical center line. The electrical shapes of the antennas are composed of a monopole-loaded loop and an open wire. The open wire functions as either a director or re∞ector for the two antennas. Depending on the switching state, the antennas can select between two beam directions with no input impedance difierence. The sizes of each antenna are then optimized to achieve beam switching capability using PIN diodes and FETs. The re∞ection coe-cients and gain patterns for two bias conditions using both switches are measured and compared with the simulated results. The measured results show that the proposed antennas can clearly alternate their beam directions using the switching components.

Beam pointing errors of phased arrays for digital switched beam acoustic radars

Abstract Phased array antennas and corresponding driving electronics units have been introduced in Atmospheric Acoustic probing. Using modern microprocessor systems in conjunction with suitable digital electronics, it is possible to implement an acoustic probing system, with full beam switching capabilities. The radiation pattern of a planar M × N phased array acoustic radar equipped with digital phase shifting circuits for the beam switching, is examined and all the necessary formulas are presented. For a given accuracy of phase quantization, the set of beam pointing directions which can be achieved without deterioration, due to this quantization, is computed and diagrams showing the mapping of the available beam pointing directions throughout space are presented. The relation between the cardinal number of this set of directions and the accuracy of the phase quantization is also presented. The beam pointing errors, due to the accuracy of the phase quantization and the dissimilarities among the array's elements are analysed using simulation techniques

18-25 GHz low-noise Line Receiver for the Tidbinbilla 64-m Antenna

A K-band (18-25 GHz) reflected-wave ruby maser (Moore and Clauss 1979) has been borrowed from the National Radio Astronomy Observatory for radio astronomy use on the NASA 64-m antenna of the Deep Space Network at the Tidbinbilla Tracking Station, near Canberra. The purpose of the installation is to provide additional sensitive spectral line, continuum, and VLBI capabilities in the southern hemisphere. Previous measurements at 22.3 GHz (λ = 13.5 mm) determined that the Tidbinbilla 64-m antenna has a peak aperture efficiency of ˜22%, a well-behaved beam shape and consistent pointing (Fourikis and Jauncey 1979). Before installing the maser on the antenna a cooled (circulator) switch was added to provide a beam-switching capability, and a spectral line receiver following the maser was incorporated. The system was assembled and tested at JPL in late 1980 and installed at Tidbinbilla early in 1981. We give here a brief description and present some of the first line observations made in February and March 1981. Extensive line and continuum observations are planned with the present system and a program is under way to determine the telescope pointing characteristics.