सुधार

IT IS WELL-KNOWN that printed antennas possess attractive features such as lightweight, compact size, linear polarization and low profile in comparison to the conventional wire antennas [1].

Such advantages allow decreasing overall system size.

These antennas have attracted research attention due to their applications in wireless communication systems.

In the last decade, there have been published number papers on the investigation of printed dipole antennas.

In [2] authors presented printed dual-band antenna comprised printed balancing unit, which operates over wide frequency band.

Such design contributes to the fully planar implementation so that it can be used in planar antenna arrays.

The primary motivation for designing two-port antenna supplied by a ring power divider is its potential usability in very specific areas such as radiolocation and space industry where there are strict requirements for weight and size of antennas.

In addition, in this design a power divider and radiators are placed above integrated balun so that a balun transforms terminal-fed dipole input impedance and impedance of the divider.

Moreover, since many applications need to have summing and differential channels it is desirable to integrate such both into one fully printed module.

Two-port radiating elements, such as those reported in [3] appear to have desirable characteristics when designing wireless communication systems.

For particular purposes such as signal selection against the background of spatial noise this kind of antennas might be the solution [Skolnic].

In relevant problems it is important to have good isolation between channels.

In radiolocation problems, channels must be designed to form summing and differential RP.

In [5] authors consider four-port printed antenna array supplied by a beam-forming network, which comprises Gysel cell.

In that work authors achieved good isolation between channels as well as appropriate radiation characteristics