Gamma rays
I don't think there is a limit, as to how high the frequency can get. The EM waves of the highest energy (and frequency) are called "gamma rays".
The highest frequency in the electromagnetic spectrum is found in gamma rays. These rays have the shortest wavelengths and the highest energy levels of all electromagnetic waves.
Gamma rays have the highest energy in the electromagnetic spectrum. They have the shortest wavelengths and highest frequencies, making them the most energetic form of electromagnetic radiation.
Gamma rays have the highest energy on the electromagnetic spectrum. They have the shortest wavelength and highest frequency, carrying the most energy of all electromagnetic waves.
The energy of EM radiation depends on its frequency, and the lowest frequency corresponds to the lowest energy. Radio waves are at the low end of the energy and frequency spectrum.
The highest frequency part of the electromagnetic spectrum is gamma rays. Gamma rays have the shortest wavelengths and highest energy of all electromagnetic waves.
Most of the EM spectrum is visible light.
-- The lowest frequencies that we have a name for are what we call "radio" waves. -- The highest frequencies that we have a name for are what we call "gamma" rays. Although there is not upper or lower limit in the electromagnetic spectrum.
The smallest part of the electromagnetic spectrum is the gamma rays. They have the shortest wavelengths and highest frequencies among all types of electromagnetic radiation.
The electromagnetic spectrum, from highest to lowest wavelength, is ordered as follows: Gamma rays, X-rays, ultraviolet (UV) light, visible light, infrared light, microwaves, and radio waves.
The categories of the electromagnetic (EM) spectrum, in the ascending order of their frequencies are:RadioMicrowaveInfraredVisibleUltravioletX-rayGammaHence, Radio waves have the lowest frequency and the longest wavelengths while Gamma rays have the highest frequency and the shortest wavelengths.(check related link for an image)
The highest frequency is gamma rays And the lowest is radio waves