why it is necessary to use a carrier for the radio transmission of baseband signals?The transmission of EM fields through space is accomplished with the use of antennas. The size of the antenna depends on the wavelength and the application.Bandpass modulation can provide other important benefits in signal transmission.If more than one signal utilizes a single channel, modulation may be used to separate the different signals. Such a technique. known as frequencydivision multiplexing