A NEW METHOD OF FREQUENCY SYNTHESIS,

A number representation scheme is described which can be applied to frequency synthesizers such as are used in communication transmitters and receivers. The scheme permits a very large number of frequencies to be constructed from a much smaller set of fundamental basis frequencies. This approach may be applied to a variety of different communication requirements, such as airborne or portable equipment where weight or volume limitations are important, and wideband spread spectrum techniques. In the latter field the basis frequencies may be gene rated by other synthesis techniques, but mixed by the methods shown here. A distinction between nonlinear mixers and linear modulators for summing frequencies is described, and it is noted that for ease of separation of spurious products the linear modulator appears more desirable. Finally, the mathematical basis for the number representation scheme is described and tables useful to the design engineer are included, covering most cases of estimated practical value. Author