https://www.electronicdesign.com/technologies/communications/article/21755680/220-mhz-transmit-combiner-cuts-intermodulation-interference
220-MHz Transmit Combiner Cuts Intermodulation Interference | Electronic Design
The DB4370-DPM series of transmit combiners for the 217- to 221-MHz range uses high Q tuned cavities to greatly reduce intermodulation (IM) interference in...
220 mhzintermodulation interferencetransmitcombinercuts