Direct Generation of MSK Modulation at Microwave Frequencies

Direct generation of a modulated signal at microwave frequencies offers considerable simplicity and economy in the transmitter of a microwave communication system. Minimum-shift-keying (MSK) is a digital modulation which yields the same bit-error-rate performance as coherent PSK even though this modulation may be generated as a continuous phase frequency-shift- keying. Utilizing this feature of MSK, this paper describes novel circuits for generation of MSK modulation at microwave frequencies.