Broadband matching of shorted antennas

B. V. Chernyshev

Special Design Bureau, Kotel’nikov Institute of RadioEngineering and Electronics of Russian Academy of sciences, Vvedensky sq. 1, Fryazino Moscow region, 141190, Russia

 

The paper is received on June 7, 2017

 

Abstract. Matching circuit based on the Chebyshev bandpass filter and L-shaped matching circuit are compared in order to provide broadband matching of the shorted antennas with the feeder. A method for matching antennas is proposed using a two-link Chebyshev bandpass filter, the elements of a serial loop of which are either a capacitive component of the resistance of radiation of a shortened dipole antenna or an inductive component of a magnetic antenna. The calculation of matching circuits has been carried out for a shortened dipol antenna and a magnetic antenna. The graphs of AFC and S₁₁ depending on the frequency are represented. The calculation of active and reactive components of the input impedance of antennas was carried out with using the two-link Chebyshev bandpass filter and the L-shaped circuit for output resistance of the filter matching to the 50-ohm line.

The graphs, based on the calculations performed, of the dependence of the antenna bandwidth on the degree of shortening for a shortened symmetrical dipole antenna and for a magnetic antenna are represented. Calculations of the matching circuits with using the Chebyshev bandpass filter were carried out and comparison with the L-shaped circuit was made.

Conclusions:

- matching of the shortened dipol antenna, with the degree of shortening η = 2, using Chebyshev two-link bandpass filter allows to increase antenna bandwith as much as 2,5 times as compared to matching using of the L-shaped matching circuit;

- matching of the magnetic antenna, with the degree of shortening η = 2, using Chebyshev two-link bandpass filter allows to increase antenna bandwith as much as 3 times as compared to matching using of the L-shaped matching circuit.

Keywords: symmetrical dipol antenna, magnetic antenna, matching circuit. 

References

1. Voitovich N. I., Sokolov A. N. Vibratornye antenny. [Dipole antennas]. Chelyabinsk, YurGu Publ., 2001, 76 p. (In Russian)

2. Fusko V. Microwave circuit: Analysis and computer-aided design. Prentice Hall; First Edition edition (March 1987), 352 p.

 

For citation:

B. V. Chernyshev. Broadband matching of shorted antennas. Zhurnal Radioelektroniki - Journal of Radio Electronics, 2017, No. 7. Available at http://jre.cplire.ru/jre/jul17/1/text.pdf. (In Russian)