Designing a patch system to interface between HF and VHF radios

High frequency (HF), (3-30)MHz, and Very high frequency (VHF), (30-300)MHz, radio are the backbones of communication systems from many years. They are playing a major role in country wide communication system. Unfortunately there is no direct interface between these two radio frequencies. A lot of research work had been done to create a cross patch between HF radio and VHF radio. The search for a complete solution for this cross patch circuit is still in progress. The idea in this paper is to design at least two versions of crosspatch circuits with different mechanisms and have a comparative study between these circuits to find out which one is better. The Crosspatch circuits would be a two way communicating circuit to interface between HF and VHF frequency ranges, and will not depend on any external signal rather will take the help of an internal signal to provide the interfacing.