A Self-Adapting Flexible (SELFLEX) Antenna Array for Changing Conformal Surface Applications

Abstract

S-Shaped Conformal ArrayAs far as the S-shaped conformal array is concerned, once again the projection method proves to be an effective mean for pattern recovery. Figure 10 shows the absolute value of the co-polar component of the electric field jE / j of the S-shaped array without and with phase-compensation, normalized with respect to the peak value obtained through simulations for the corrected array: the co-polar component is shown, since the cross-polar one (i.e., jE h j) is well below 230 dB. First of all, as in the previous case it can be noticed that simulations and measurements from the realized prototype (represented in Fig. 11) agree. It can be seen that the main lobe direction changes from 08 to 98 with respect to the linear case, and that the side lobe level has consistently increased from 213.8 dB to 26 dB. The gain of the 1 3 4 undistorted linear array was 11:1 dB, when the array is deformed it becomes 10.5 dB in the new direction of maximum at h59 while it is only 8.2 dB for h50 (the original direction of maximum); after compensation the gain in the desired direction of maximum (i.e., h50 ) increases to 10.8 dB. Applying the projection method the radiation pattern can be recovered: the main lobe direction moves back to 08 and the side lobe level decreases to 211 dB. CONCLUSION

Design and Simulation of Fully Printable Conformal Antennas With BST/Polymer Composite Based Phase Shifters

“…Deformation of an antenna array from a planar geometry to a non-planar geometry results in the distortion of the radiation pattern and consequently in the degradation in antenna performance, such as lower maximum gain and higher side lobe levels [15]. Here, we study two different bending profiles and the bending effects on the realized radiation pattern, following our previous work [38].…”

“…The bending of the surface alters the distances between the antenna elements [8,15]. Consequently, the elements no longer lie on the same plane and significant vertical displacement appears.…”

“…Many attempts have been made to study and address the deteriorative effects of bending on radiation pattern of conformal antennas [12][13][14]. In a more recent work, an autonomous self-adapting capability is developed for a flexible microstrip antenna array by utilizing locally based sensors and a feedback analog circuit to detect and recover the pattern of the conformal antenna array for different deformations [15]. In previously reported studies including the latter work, compensation is commonly achieved by locating a commercially available tunable phase shifter at the feed line of the array elements to adjust the phase of the spatially displaced elements, thus recovering the distorted radiation pattern.…”

Main Lobe Control of a Beam Tilting Antenna Array Laid on a Deformable Surface

“…In particular, if strain sensors between adjacent antennas are used to measure the surface deformation, then the distance of the elements from the xy-plane can be directly computed from the sensor data [5]: no analytical expression of this distance in the function of the deformation geometry must be provided.…”

“…The projection method effectiveness was thoroughly studied for many types of antennas, as, for example, 1 × 4 and 1 × 6 linear arrays placed on surfaces that change shape in time [5][6][7] and planar arrays subject to cylindrical [8], spherical [9], and asymmetrical [10] surface deformations. All the aforementioned works adopt the PM in order to recover the pattern of broadside arrays, but a common requirement when dealing with phased arrays is to dynamically steer the main lobe towards different desired directions.…”