What characteristic of a receiver is impacted by the selectivity of its IF circuitry?

The selectivity of a receiver's intermediate frequency (IF) circuitry primarily affects signal resolution. Selectivity refers to the ability of the receiver to distinguish between different frequencies or signals that are closely spaced. A highly selective IF stage can effectively filter out unwanted signals or noise that are near the desired signal frequency, thereby allowing only the intended signal to be processed.

When the IF circuitry is designed with good selectivity, it enhances the receiver’s ability to resolve between closely occurring signals, minimizing interference and ensuring that each signal can be distinctly interpreted. This characteristic is crucial for accurate demodulation and decoding of signals, especially in crowded frequency environments.

In contrast, signal amplification deals with increasing the power of a signal, noise reduction refers to suppressing background noise rather than resolving signals, and frequency stability pertains to maintaining a constant frequency over time. While all of these aspects are important in a receiver's performance, selectivity's direct impact is most prominently on the signal resolution.