Microwave dryer of a print system with modulation of the microwave source using frequency shift keying

A method comprising:

• operating a microwave source coupled to a waveguide by generating electromagnetic energy at an operating frequency with the microwave source and transporting the electromagnetic energy with the waveguide to dry a wet colorant applied to a continuous-form print media by a printer, wherein the waveguide includes a structure with a long axis that extends across a width of the print media, and includes a passageway through the structure to pass the print media through a short axis of the waveguide, wherein the passageway is sized to pass the continuous-form print media through the structure;
• determining, with a processor, a period of time for the print media to traverse through the short axis of the waveguide;
• determining a modulating signal with a modulating frequency based on the period of time;
• determining a number of frequencies that approximate the modulating signal at the modulating frequency;
• and
• applying binary values that represent the number of frequencies to an input of a frequency shift keying (FSK) modulator to modulate the operating frequency with a series of discrete frequencies that vary intensity positions to reduce a variation of intensity of the electromagnetic energy in a direction across the width of the print media over the period of time.

A non-transitory computer readable medium embodying programmed instructions which, when executed by a processor, are operable for performing a method for operating a microwave dryer that includes a microwave source coupled to a waveguide, the microwave source operable to generate electromagnetic energy at an operating frequency, and the waveguide operable to transport the electromagnetic energy with the waveguide to dry a wet colorant applied to a continuous-form print media by a printer, wherein the waveguide includes a structure with a long axis that extends across a width of the print media, and includes a passageway through the structure to pass the print media through a short axis of the waveguide, wherein the passageway is sized to pass the continuous-form print media through the structure, the method comprising:

• determining, with a processor, a period of time for the print media to traverse through the short axis of the waveguide;
• determining a modulating signal with a modulating frequency based on the period of time;
• determining a number of frequencies that approximate the modulating signal at the modulating frequency;
• and
• applying binary values that represent the number of frequencies to an input of a frequency shift keying (FSK) modulator to modulate the operating frequency with a series of discrete frequencies that vary intensity positions to reduce a variation of intensity of the electromagnetic energy in a direction across the width of the print media over the period of time.