1. A 4-element dipole array has element spacing of 2/2. The elements are excited by sources with the same magnitude but different phases as show in the figure below (y=0°). Assume the phase of element 1 to be zero. Sketch the resulting radiation pattern in the xy-plane using the graphical method. (hint: u= kodsin Osind+ y where 0= 90° in xy plane.) 1 20° Top View 2 3 4 مر23 22 /

Find out the radiation resistance of a quarter wave dipole antenna.

If a half wave dipole antenna has a peak antenna current of 10 A, then estimate the power radiated by the antenna.

What will be first null beam width of a paraboloidal reflector antenna operating at a frequency of 4 GHz and having a diameter of 20 m?

A half-wave dipole, which has a total length of L = 1.39 cm (i) Analyze the resonant frequency fr. (ii) Determine the new fr when the dipole length is 3L. (iii) Determine the radiation resistance of a quarter-wave monopole that hasa total length of L.

1. A quarter-wave dipole oriented on z-axis is placed vertically at a height of h = 0.285A above an infinite electric ground plane, a. Write the expression of the electric field, b. Plot the element factor, array factor, and total pattern on yz-plane, c. Redo parts (b) if h = 0, d. Find the input impedance of the dipole if h = 0.

A half-wave dipole, which has a total length of L = 2.00 cm. (i) Analyze the resonant frequency fr. (ii) Determine the new fr when the dipole length is 3L. (iii) Determine the radiation resistance of a quarter-wave monopole that has a total length of L.