🔍 Key Concepts

• RF (Radio Frequency) amplification in a receiver front end • Differences between sensitivity, selectivity, and signal-to-noise ratio (SNR) • How an RF amplifier stage affects the detector (demodulator) that follows it

💭 Think About

• For each choice, ask yourself: does an RF amplifier directly improve this characteristic, or is that more associated with another stage (like IF or audio)? • Think about what happens if you place a low-noise RF amplifier right at the antenna input—what gets better before the signal is filtered or detected? • Consider which benefits might be side effects versus the primary design goals of adding RF amplification.

✅ Before You Answer

• Be clear on the difference between sensitivity (weak-signal handling) and selectivity (ability to separate close frequencies). • Consider whether signal-to-noise ratio is improved at the RF stage, and how noise from later stages compares to noise at the front end. • Ask if more efficient and more stable detector operation is a commonly cited, primary advantage of adding an RF amplifier stage, or more of an indirect/conditional benefit.