Question

subject:Antenna and propagation

09. Design an end fire polarized helix antenna having a half-power beamwidth (HPBW) of 45°, pitch angle is 13°, circumference of the helix is 60 cm at a frequency operation of 500 MHz. Determine, (1) Number of turns needed (ii) Diameter of a turn on the helix antenna Total height of helix antenna (iv) Directivity in decibel. (v) Axial ratio (vi) Draw the helix antenna design (13 Marks) (CO2, PO4, C6]

Answer 1

Each part of the question has been solved in details, with proper calculations and design, results are marked with red boxes -
9 frequency f = 500 MHz N° cad=60 cm 60cm for notis L = fors (3) cfona cotom 13°=60 (0.23) 13.852 cm s - s = 13.852 cm 3/2 HP BW (degrees) = 45 = 52. B CONS 59 (60)/2 GO UN (13.852) = 52( 464.757) Gov N. (17.852) 52.(464:758) ro (45) ND (09) 2.19.872 5.7839 Number of TN F 6 tums

(ii) Diameter of a tum pitch arogle x = tant forma 2 > storia = 13.85 tana AX form 13° D = 19.095 (1) Total height of helix antenna 5 (528. 21) n H = 6X 13.852 Н - 83.112 cm (23.11). / (iv) Directivity in (dB) Doa ISNc2s 15X6(43.852) (60) 13 (60)? 22 Do = 13.176 dB

(W) axial Roto ARE 12 г). 08 31 2 N ++) AN 2 (c) t) 12 А = o8 33 Design: Axial Mode ко сах 000,