Difficulty: Easy
Correct Answer: 30, 60 and 70 MHz
Explanation:
Introduction / Context:
Microwave and radar receivers use down-conversion from gigahertz RF to a convenient IF where filtering and amplification are practical. Standardized IFs simplify filter design and system interoperability.
Given Data / Assumptions:
Concept / Approach:
Common IFs for microwave superhets include ~30 MHz, ~60 MHz, and ~70 MHz (and their near variants). These strike a balance between image rejection, filter availability (crystal/SAW), and achievable IF gains.
Step-by-Step Solution:
Verification / Alternative check:
Radar/receiver literature and module catalogs list 30/60/70 MHz IF chains as industry staples.
Why Other Options Are Wrong:
Common Pitfalls:
Final Answer:
30, 60 and 70 MHz
Discussion & Comments