YIG-based closed loop signal filtering and amplitude control

A closed-loop controlled YIG resonator device, said device comprising:

• a YIG resonator positioned in an electromagnetic coil voltage controlled magnetic field configured so that a YIG resonant frequency of said YIG resonator is tuned by said electromagnetic coil voltage;
• said YIG resonator magnetically coupled to both an input coupling wire and an output coupling wire such that said input coupling wire, and said YIG resonator, transfer input signals to said output coupling wire, thus producing output signals, according to a response curve that is highest when said YIG resonant frequency of said YIG resonator is tuned to an input frequency of said input signals;
• YIG resonator device further comprising a closed-loop controller configured to operate said YIG resonator in a detuned mode so that said input frequency falls on a shoulder of said response curve, thus producing an attenuated output signal where changes in YIG resonance frequency alter an amount of attenuation of said attenuated output signal;
• said closed-loop controller further configured to detect said amount of attenuation, compare said amount of attenuation versus a reference, and use differences between said amount of attenuation and said reference to control said electromagnetic coil voltage;
• wherein said device further comprises a comparator device;
• and
• wherein said closed-loop controller is further configured to use said comparator device to compare said amount of attenuation versus a reference.

A closed-loop control method of operating a YIG resonator device, said method comprising:

• obtaining a YIG resonator positioned in an electromagnetic coil voltage controlled magnetic field such that a YIG resonant frequency of said YIG resonator is tuned by said electromagnetic coil voltage;
• said YIG resonator being magnetically coupled to both an input coupling wire and an output coupling wire such that said input coupling wire uses said YIG resonator to transfer input signals to said output coupling wire, thus producing output signals, according to a response curve that is highest when said YIG resonant frequency of said YIG resonator is tuned to an input frequency of said input signals;
• operating said YIG resonator in a detuned mode so that said input frequency falls on a shoulder of said response curve, thus producing an attenuated output signal where changes in YIG resonance frequency alter an amount of attenuation of said attenuated output signal;
• detecting said amount of attenuation, comparing said amount of attenuation versus a reference, and using differences between said amount of attenuation and said reference to control said electromagnetic coil voltage;
• wherein said reference comprises a reference voltage provided by a computer-processor-controlled digital-to-analog converter.