Varactor-Loaded Pattern Reconfigurable Array for Wide-Angle Scanning With Low Gain Fluctuation

Abstract

An improved phased array using pattern reconfigurable antenna elements in this communication is proposed to realize wide-angle scanning performance with low gain fluctuation. The pattern reconfigurable element is a microstrip Yagi antenna with its parasitic strips loaded with varactors. The reconfigurability of radiation pattern from the element is enabled by tuning the capacitive reactance of the varactors. Five elements were arranged in an equally-spaced linear array, and the effects of several key parameter variations on the radiation characteristics of the array are provided. The proposed array is fabricated and experimentally verified. It is seen from the measured results that the main beam of the array can scan from -70° to 70° in the H-plane with a gain fluctuation less than 2 dB. Meanwhile, the coverage of 3 dB beamwidth of the array is from about -87° to 87°. The agreement between simulated and measured results validates our design exhibiting a good performance of wide-angle scanning.

Design of Frequency- and Pattern-Reconfigurable Wideband Slot Antenna

“…In [7], a lumped capacitor is inserted in the middle of a slotted patch antenna, and the operation bands can be tuned continuously. In [8], an improved phased array pattern-reconfigurable antenna is proposed. By tuning the capacitive reactance of the varactors, the main beam of the array can scan from −70°to 70°in the H-plane.…”

A compact dual circular patch pattern reconfigurable antenna

“…Moreover, the ease of handling and integration with a planner antenna is not well entertained by MEMS. Use of varactor diodes is another resort of producing reconfigurability, where a varying dc voltage results in a variable capacitance, and thus, an antenna structure equipped with a variable capacitance can provide a dynamic reconfiguration capability . Yet, it suffers from low dynamic range, nonlinearity and complex biasing networks design .…”

“…Use of varactor diodes is another resort of producing reconfigurability, where a varying dc voltage results in a variable capacitance, and thus, an antenna structure equipped with a variable capacitance can provide a dynamic reconfiguration capability. 7 Yet, it suffers from low dynamic range, nonlinearity and complex biasing networks design. 8 PIN diodes enjoys the liberty of low dc voltage biasing requirement, high-power handling capacity, high-speed switching (1-100 nsec) and exceptionally low cost that makes it a suitable candidate for the reconfiguration capability of the planner antennas.…”

A novel wideband pattern reconfigurable antenna using switchable parasitic stubs

“…Pattern diversity antennas are used in various wireless communication systems such as base station antennas, mobile handset antennas and MIMO diversity antennas . The reconfiguration mechanism can be realized by using double‐pole double‐through (DPDT) switch or varactor diode or RF switch or pin diode or GaAs FET switch, microelectromechanical switches (MEMs) or artificial transmission lines . A great deal of research has been explored on the design of pattern reconfigurable antenna including tunable impedance surface, shared radiating aperture, Frequency selective surfaces, parasitic layer‐based, switchable feed networks, switching alternate reflector and radiator, liquid metal reflector stacked array and artificial structures .…”