Which statement is incorrect regarding microwave transmissions?

Microwave transmissions have specific characteristics that distinguish them from other forms of communication. The statement that microwave signals travel in curved lines is incorrect as microwaves typically travel in straight lines, especially over relatively flat terrain or when obstacles are minimal. The straight-line propagation is primarily due to the relatively high frequency and wavelength of microwave signals, which are more akin to line-of-sight communication.

The other options accurately describe the properties of microwave transmissions. For instance, microwave signals do penetrate fog and snow to a certain degree, allowing for reliable communication even in adverse weather conditions. They are also transmitted in short radio waves, which is characteristic of their frequency range, making them suitable for high-bandwidth applications. Moreover, the ability to transmit a large number of microwave signals simultaneously is a key advantage of this technology, allowing for the multiplexing of multiple signals within the same frequency range.