Apparatus and method for increasing the maximum input frequency of a frequency divider

An apparatus for increasing the maximum input frequency of a frequency divider, the apparatus comprising:

• a frequency mixer circuit to receive as input a first input frequency signal, a second input frequency signal and to generate a combination signal wherein the combination signal is a frequency subtraction of the second input frequency signal from the first input frequency signal;
• at least one frequency divider circuit in operative contact with the mixer to receive and to frequency divide the combination frequency signal by a predetermined number;
• and
• at least one of a signal splitter and a directional coupler in operative contact with the frequency divider to receive the divided frequency signal and to generate an output frequency signal and a feedback frequency signal wherein the feedback signal having a frequency identical with the output frequency signal and wherein the feedback frequency signal constitute the second input frequency signal.

A frequency divider system, comprising:

• a mixer, operative to receive an input frequency signal of which the frequency is to be divided;
• a frequency divider, coupled to an output of the mixer, the frequency divider being operative to divide the output of the mixer by a predetermined division ratio into a frequency-divided output frequency signal;
• and
• an output unit, being operative to output the frequency-divided output frequency signal and feed the divided output frequency signal back to the mixer, such that the output of the mixer becomes a combination signal of the input frequency signal and the divided output frequency signal;
• wherein
• the combination signal has a frequency equal to an addition of frequencies of the input frequency signal and the divided output frequency signal.