Dish antennas are a common type of antenna at high frequencies. (a) Explain the design and operation of dish antennas with the use of equations and diagrams. Discuss different types of dish antennas and identify the main advantages and disadvantages of each type. Identify the main trade-offs between different types of dish antennas and suggest ways to improve efficiency.

Explain the helical antenna with respect to structural design, working principle in axial mode and normal mode, their merits, demerits and applications.

Problem 4. We need to allocate requirements to a parabolic antenna gimbal system and spacecraft. Our aperture size is 1 meter in diameter and transmission frequency is 5 GHz. We need to maintain pointing loss to < 0.5 dB. a. What is the ideal gain, at peak of beam, for the antenna at the given frequency? b. What is the beam width in degrees, using the equation given in class? c. What is the maximum allowed pointing error to not exceed the pointing loss?

a) Explain the terms: radiation pattern, radiation efficiency factor, wire- type antenna, permittivity and antenna aperture efficiency.