Low passive intermodulation chokes for electrical cables

A cellular antenna array comprising:

• at least two antenna sub-arrays, wherein each of the at least two antenna sub-arrays comprises at least two antenna elements;
• a splitting module configured to couple the at least two antenna sub-arrays to at least one feed line;
• at least two electrical cables coupling the splitting module to the at least two antenna sub-arrays;
• wherein each of the at least two electrical cables has a first choke at or near a first end of the electrical cable and a second choke at or near a second end of the electrical cable;
• wherein each of the first and second chokes is configured to suppress undesired radiofrequency (RF) current, each of the first and second chokes are configured to exhibit low passive intermodulation (PIM), each of the first and second chokes comprising:
• a first electro-conductive sleeve disposed over an outer surface of the corresponding electrical cable, wherein a first longitudinal slot is disposed between ends of the first electro-conductive sleeve, and wherein the first longitudinal slot extends the full longitudinal length of the first electro-conductive sleeve;
• a second electro-conductive sleeve disposed over the first electro-conductive sleeve, wherein a second longitudinal slot is disposed between ends of the second electro-conductive sleeve, and wherein the second longitudinal slot extends the full longitudinal length of the second electro-conductive sleeve;
• and
• an insulating layer disposed between the first electro-conductive sleeve and the second electro-conductive sleeve;
• wherein the first electro-conductive sleeve and the second electro-conductive sleeve are insulated from the electrical cable.