I am working on a project to determine the distance between two objects using electromagnetic waves. So far we plan to send a signal from one object to the other object and compare that signal (sine wave) with a base signal (sine wave) and determine the phase shift of the transmitted signal. From there we can calculate the distance the wave traveled. In order to get the accuracy and distance requirements for our distance calculation we require sending and measuring the phase difference between signals sent at 3GHz, 300MHz, 30MHz, 3MHz, and 300KHz.
I was wondering if there are any products available that can help us measure the phase difference between two signals at these frequencies? Any help, even a point in the right direction would be a great help.