Why Data transmission at higher rates requires wider bandwidths?

Why Data transmission at higher rates requires wider
bandwidths?

Data rate is higher means that we are able to transmit those signals quickly,it is possible when frequency is very high then band width will be high ,note that band width is equal to highest frequency component if it is low pass signal.
(Frequency is rate at which signal changes)

Digital data is a series of ones and noughts. if you send 1010101, its a square wave (equal on and off times). Analysing a square wave, it comprises of a fundamental frequency(F) and odd harmonics , 3 F, 5F, 7F. Normaly if the fundemental gets through the system, the other components can be generated. So if you send one, nought (10) over a 1mS, this works out at a frequency (F) of 2 X 1/.001 = 500 HZ. If you send it over one microsecond, the frequency is 1000 times more ( 500,000 HZ). Your transmission system must have the bandwidth to handle these frequencies. Also if you data stream is 1,1,1,1,1,1,1. . . , its effectively a DC level so the system must be able to send this also. There are many systems designed to break up a long chain of ones or noughts to overcome the need for a true DC response.
Frank

because if you don't have enough bw or sr your high rate or high freq signal will be distorted or deformed because your system won't be able to track your signal fast variations ( for analog cases ). in digital ones having more bandwidth provide the capability of more data transferring and this(more data transferring) means high rate.

A data transmission line is like a frequency limiting pipe. The bandwidth describes at what frequency the signal amplitude at the end degrates by -3dB. For transmitting digital signals it mean that the maximal possible raise and fall time is limited by the bandwidth of the cable. If the frequency gets higher then 2x tr + 2x tf, the signal amplitude get less and less.

Enjoy your design work!

The theoretical channel capacity (maximal achievable data rate with optimal modulation) is described by the Shannon-Hartley theorem. https://en.wikipedia.org/wiki/Shannon-Hartley_theorem

As a simple conclusion, it says that the available data rate under given conditions (S/N ratio, modulation method) is proportional to bandwidth.