The radio telescope invention is accredited to Kari Guthe Jansky. A  radio telescope is basically a specialized antenna and radio receiver  used to detect radio waves from astronomical radio sources (i.e., moon,  stars, planets, etc.) The field of study is called Radio Astronomy and  studies the radio frequency portion of the electromagnetic spectrum  (E.M.). Traditional telescopes study these same astronomical objects by  analyzing the light wave portion of the electromagnetic spectrum.

     Since radio waves are at the lower frequency and relative weaker  range of the EM spectrum, they are collected and amplified by the radio  telescope antenna and receiver. These waves can then be analyzed. The  general wavelength range of these waves are from 1 millimeter to 10  meters long. Therefore, we usually refer to radio waves in terms of  their frequencies instead of their corresponding wavelengths. This is  also why radio telescopes are the world largest telescopes with the most  sensitive receivers.

     Early radio telescopes had a serious limitation in that they had  to be tuned to one specific frequency. With vast improvements in modern  electronic technology, radio receivers and computers can divide the  frequency band into several thousand separate channels that may range  from over tens to hundreds of megahertz. This modern improvement in  radio telescope technology provided a great advantage when compared to  optical telescopes. Another advantage is that radio telescopes can be  used both day and night.

Radio telescopes like the Long Wavelength Array, seen  here, do not need accurate dish surfaces to detect radio waves from  space. These use dipole antennas in a cross-shape.

                                            Reference

National Radio Astronomy Observatory. What are Radio Telescopes?  (2022). 

What are Radio Telescopes? – National Radio Astronomy Observatory (nrao.edu)Links to an external site.