Gain of circularly polarised arrays composed of linearly polarised elements

A Shared Aperture Dual-Frequency Circularly Polarized Microstrip Array Antenna

“…It is well-known that CP radiation can be achieved by applying proper phase shifts to sequentially rotated LP antenna elements [6][7][8]. We have extended this concept to the novel configuration as shown in Fig 2x2 sub-array, which can be seen as the unit cell of a larger array.…”

“…Of course, there are also disadvantages of which the relevance depends on the final application. One of the main draw-backs of sequential rotation with LP antenna elements is that relative high sidelobes of cross polarization may appear in the diagonal plane (ϕ=45 0 ) [6][7][8]. This effect strongly depends on the element spacing d, and is therefore a design parameter.…”

SCRLH-TL Based Sequential Rotation Feed Network for Broadband Circularly Polarized Antenna Array

“…When the SR techniques are used, the radiated polarization type of the element cannot be considered and the overall bandwidth performances of CP antenna arrays can be significantly improved. Until now, many CP antenna arrays using SR feed networks have been reported [4][5][6][7][8][9][10]. In [4], CP antenna array with wide axial ratio (AR) bandwidth was obtained by rotating linearly polarized elements sequentially.…”

“…In [6], a novel broadband CP antenna array was presented using SR feed technique. Instead of using linearly polarized elements in [4], [7] and [8], CP antenna elements were used to improve the AR bandwidth. However, the defected ground structure leads to back radiation and difficult encapsulation.…”

On the Use of Metal Gratings to Reduce Diffraction From a Finite Ground Plane in Circularly-Polarized Microstrip Arrays

“…An alternative method is shown in Figure 1(b). It uses sequentially-rotated linearly polarized (LP) antenna elements in an array configuration [4][5][6]. (a) (b) Figure 1.…”