A radio CATV relay system using the frequency modulated signal from 27.5 GHz to 28.5 GHz is designed by studying its system budget for 48 channel television relay at 5 kilometer span. A local oscillator is designed by using a dielectric resonator and HEMPT CFB001-03 at its oscillation frequency of 26.5 GHz. S-parameters of the HEMPT given by its data book are used in the design and its normal oscillation did not occur. Other oscillation occurred at 24.17 GHz with its output power of -23.3dBm.
