Wide-Angle Scanning Phased Array Antenna using High Gain Pattern Reconfigurable Antenna Elements

Abstract

This paper presents a wide-angle scanning phased array antenna using high gain pattern reconfigurable antenna (PRA) elements. Using PRA elements is an attractive solution for wide-angle scanning phased array antennas because the scanning range can be divided into several subspaces. To achieve the desired scanning performance, some characteristics of the PRA element such as the number of switching modes, tilt angle, and maximum half-power beamwidth (HPBW) are required. We analyzed the required characteristics of the PRA element according to the target scanning range and element spacing, and presented a PRA element design guideline for phased array antennas. In accordance with the guideline, the scanning range was set as ±70° and a high gain PRA element with three reconfigurable patterns was used to compose an 8x1 array antenna with 0.9 λ0 spacing. After analyzing whether the active element patterns meet the guideline, the array antenna was fabricated and measured to demonstrate the scanning performance. The fabricated array can scan its beam from -70° to 70° by dividing the scanning range into three subspaces. It shows that even if the array antenna has large element spacing, the desired scanning performance can be obtained using the elements designed under the guideline.

Broadband RF Phased Array Design with MEEP: Comparisons to Array Theory in Two and Three Dimensions

“…That design allowed reflections internal to the horns to distort the initial wavefront. Holding the horn-width constant in the z-direction produces radiation patterns that match Equation (25) because it follows the onedimensional example of Section 3. To obtain z-polarized wavefronts, all that is necessary is to rotate the array.…”

“…For these two-dimensional antennas, the 1/ f -dependence is a good description of the beamwidth across the [0.3-5 GHz] bandwidth. The constant term b is only necessary since the array has finite length L. The beamwidth (BW) scales inversely with array length L: BW ≈ 0.886λ/L, from Equation (25).…”

“…The radiation patterns are normalized to the power at the beam angle, and are shown in blue. The red curves represent Equation (25) with the correct N-value and d y /λ-value. Equation ( 25) is symmetric, with identical forward and backward lobes.…”

“…The index of refraction varies within the ice because of the transition between surface snow (ρ ≈ 0.4 g/cm 3 ) and the solid ice below (ρ = 0.917 g/cm 3 ). Most recent and intricate studies of phased array beam behavior still assume a uniform medium [24][25][26]. Embedded phased arrays with varying n(z) emit signals that curve in the direction of increasing n(z).…”

A Method for Tailoring the Gain Pattern of a Single Antenna Element

“…The other option is to use patternreconfigurable elements [7]- [11] for larger beam steering range in the vertical plane θ = [−90 • , +90 • ]. Arrays with wide element patterns are limited to spacings below 0.5λ to avoid emergence of grating lobes [10]. They can be avoided with pattern-reconfigurable elements since the single element does not radiate towards the grating lobes, which arise from the shape of the array factor.…”