Hello, Good day Fam.
I am trying to build a device that is able to detect Radio frequency within the band of 30MHZ - 300MHZ (VHF) and the frequency detected should be displayed on an LCD screen.
I will be very grateful if anyone here can help me out.
Will save you a lot of time and headaches....
Why do you want to build one, there are plenty of low cost ready made frequency counters avaialable ?
You don't describe the circumstances under which you want to "detect Radio Frequency" but RTL-SDR might be relevant as well. This is an inexpensive USB stick receiver intended for television reception, but which hobbyists have discovered supports radio reception across a broad range of frequencies. This wouldn't be an Arduino solution, but there is a wealth of open source support for it.
Broadly speaking one might prefer a frequency counter to verify that their own transmitter is on frequency and a receiver/scanner to determine what frequencies are being transmitted on by others.
That is a very wide band. That covers a lot of licenced users such as FM radio and aviation. There will always be many transmitters transmitting in that band.
Or is this for some kind of lab test where you plug in to the device instead of having an antenna?