elical antennas are often used for space applications where the polarizationof the other antenna is not necessarily constant at all times. To assure uninterrupted communication, the helical antenna...

elical antennas are often used for space applications where the polarization of the other antenna is not necessarily constant at all times. To assure uninterrupted communication, the helical antenna is designed to produce nearly circular polarization. For a 10-turn helix and axial mode operation, determine the following: (a) radius (in λ0), pitch angle (in degrees), and separation between turns (in λ) of the helix for optimum operation. (b) half-power beamwidth (indegrees). (c) directivity (indB). (d) axial ratio (dimensionless). (e) minimum loss (in dB) of the received signal if the other antenna of the communication system is linearly polarized: 1. inthe vertical direction; 2. at a 45◦ tilt relative to the verti