Why are space communication links moving to Ka-band (20–30 GHz)? Choose the primary technical advantage that motivates this migration (assume link design accounts for propagation impairments).

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Introduction / Context: Modern satellites increasingly exploit Ka-band to meet exploding capacity demands from broadband and video. This question probes the main technical driver behind choosing Ka-band despite its well-known propagation challenges. Given Data / Assumptions: Ka-band spans roughly 20–30 GHz for satellite services. Higher frequency bands provide more spectrum allocation opportunities. Propagation issues (rain fade, atmospheric absorption) can be mitigated with link design (power, coding, adaptive modulation). Concept / Approach: The primary motivation is access to larger contiguous bandwidth, enabling higher aggregate throughput. While smaller antennas are possible due to shorter wavelengths, that is a secondary practical benefit; crucially, statements claiming “no atmospheric or rain attenuation” are incorrect—Ka-band is more susceptible and needs mitigation. Step-by-Step Solution: Identify the real advantage: spectrum availability → capacity growth.Reject claims removing physical propagation limits (rain/atmosphere still affect Ka).Select the bandwidth argument as the most accurate and general reason. Verification / Alternative check: Operator whitepapers and textbooks cite “more bandwidth at Ka-band” as the core reason for adoption, with engineering countermeasures to handle higher fades. Why Other Options Are Wrong: “No atmospheric or rain attenuation” is factually wrong; Ka-band is more fade-prone. “Smaller antennas” can be true, but is not the primary capacity driver compared to bandwidth availability. Common Pitfalls: Assuming Ka-band is superior in every respect. It provides capacity, but needs robust fade mitigation techniques. Final Answer: It offers a much wider available bandwidth for services and carriers

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