u00bd frequency divider further frequencies of 1056 mhz and 264 mhz are input into a first image rejection mixer to generate a frequency of 792 mhz a frequency of either 792 mhz or 264 mhz and an oscillator frequency of 4224 mhz are input into a second image rejection mixer to effect frequency conversion 4224 u2212 792 3432 mhz 4224 u2212 264 3960 mhz or 4224 u2212 792 3432 mhz consequently a desired 3 band rf carrier can be generated the lower block diagram in fig1 is an enlargement of the first image rejection mixer since a u00bd frequency divider performs a 90 degree phase shift a frequency of 264 mhz is a rectangular wave that is phase shifted by 90 degrees it can be expressed as the sum of a fundamental wave 4n u2212 1 order harmonic and 4n 1 order harmonic as indicated by equation 16 as indicated in fig1 the fundamental wave and 4n 1 order harmonic have a negative frequency whereas the 4n u2212 1 order harmonic has a positive frequency therefore only the third order harmonic can be suppressed for instance by allowing the wave to pass through a polyphase filter whose frequency response is illustrated in fig7 if the wave is allowed to pass through a polyphase filter whose frequency response is indicated in fig9 the third and fifth order harmonics can be both suppressed fig1 shows output spectrums of the multiband generator shown in fig1 the left hand spectrum illustrates a case where the third and fifth order harmonics are suppressed the central spectrum illustrates a case where only the third order harmonic.