Direct-type binary frequency synthesizer for microwave frequencies

摘要

An apparatus including means for providing at least four fixed internal frequency signals having four different values of frequency in which all of said frequencies are coupled into a first processor stage comprised of a single pole double throw switch controlled by a first input bit command signal for selecting either of two of said four frequencies for coupling into a first frequency mixer. A third frequency signal is also coupled into the first frequency mixer which provides a first difference frequency output signal that is coupled into a binary frequency divider. The divider output signal is then coupled along with a fourth frequency signal into a second frequency mixer which produces a second difference frequency output signal that is coupled into a third mixer in an output stage which also includes a second single pole double throw switch controlled by a second input bit command signal for selecting either of the same two of the four frequency signals to also be coupled into the third frequency mixer. The output signal produced by the third mixer is a discrete synthesizer frequency output signal selected from a range of frequency output signals in accordance with the input bit command signal. Additional identical processor stages may be added to provide smaller increments between the selectable discrete synthesizer frequency output signals.