Conversion of a donut-shaped pattern to a directive one using a wide frequency band hive-shaped pattern director antenna

ABSTRACT

In this paper, a pattern director antenna (PDA) with 4 GHz bandwidth was designed, simulated, and measured. In the past, to convert a donut-shaped pattern into a directive, mode converters have been used. But their losses, weight, size, and cost additions had a negative impact on the total system performance. Furthermore, the very low bandwidth of the mode converters prevented their use in a broadband source. When testing an electromagnetic diode, the operating frequency may change dramatically. PDA is best used to change the output mode of electromagnetic sources which their frequency is a function of the size of the electromagnetic source and voltage applied. To solve this problem, we propose the pattern directors. The PDA accepts directly (without the need for mode conversion) an azimuthally symmetric generated mode of an electromagnetic source and radiates a directive and pencil-beam pattern. 3D printer technology has been used to reduce manufacturing costs. The gain is from 17 to 22 dB in the frequency band. The S₁₁, main lobe deviation (MLD), and sidelobe level (SLL) are less than −15 dB, 2°, −6 dB in all frequency band, respectively. Also, the 3 dB beamwidths are 4 to 8 and 11 to 15 in the E and H plates, respectively. The pattern was measured at three frequencies in the frequency band. The simulation results are a good agreement with the measurement.

KEYWORDS:

• Pattern director antenna
• mode converter antenna
• wideband antenna
• hexagonal waveguide
• circular waveguide
• electromagnetic source

Disclosure statement

No potential conflict of interest was reported by the author(s).