An Alignment Technique for Multiple Ball YIG Bandpass Filters Operating Over Multi-Octave Frequency Bands

To date, the alignment of a multi-sphere YIG bandpass filter for multi-octave frequency bands has been designated as a "Black Art" performed by a rare breed of highly skilled and patient individuals. The intent of this paper is to bring YIG filter alignment out of the realm of "tweaking and hunting", thereby significantly reducing the cost per unit. A logical step by step alignment procedure applicable to any YIG or Ga YIG multi-sphere bandpass filter is presented. The validity of the technique has been verified by many successfully aligned complex filters.