An independent loop, labeled (1), was first implemented to make sure that the load
impedance matches with the line impedance.
When the elements of the folded dipole and the Alford loop are combined, the desired
impedance match can be achieved using the properties of a folded dipole, and the desired radiation pattern can be reached from the Alford loop shape.
At low frequency, the return loss is about--40 dB, a very good
impedance match to 50[OMEGA].
This requires a broadband wide-scan
impedance match with elements spaced as closely as 0.1 wavelength.
This is accomplished while maintaining the
impedance match at the design frequency and without the need to increase the substrate's dielectric constant.
Active termination provides higher pull up current and a better
impedance match; the characteristics do not change will termpower fluctuations.
With this feed configuration, a good
impedance match has been achieved for a narrow slot, and an impedance bandwidth of approximately 20 percent has been obtained.
The centre frequency of the 10-dB working band will move to higher frequency and the
impedance match will be better by increasing g, the corresponding reflection coefficients and axial ratios for different g values are given in Fig.
The proposed antenna shows a good
impedance match over a wi de frequency band.
Good
impedance match is obtained with a conventional feeding structure, only for narrow slots.
The limiting conditions of
impedance match are defined by Equations 10 for an infinite number of matching elements, and by a chart presented in Fano [5] for various finite numbers of matching elements.
The beveled ground plane and the CPW-fed patch could result in a smooth transition from one resonant mode to another and ensure good
impedance match, especially at the upper frequencies.
