Low passive intermodulation chokes for electrical cables

摘要

This disclosure relates to chokes for suppressing undesired signals such as such as common mode electromagnetic interference (EMI) and/or radio frequency interference (RFI). The chokes can include an electro-conductive sleeve disposed over an electrical cable and the sleeve can be configured to suppress an undesired signal. In some embodiments, the electro-conductive sleeve and have a half-wave sleeve, which can be electrically open at both ends. Additional insulating material can be included between the electrical cable and the sleeve. Multiple electro-conductive sleeves and be disposed substantially concentrically over the cable. The chokes can be configured to reduce passive intermodulation (PIM). The sleeve can have a longitudinal slot that extends the length of the sleeve. The sleeve can include multiple slots that separate the sleeve into multiple panels, which can be configured to suppress different signals.

主权项

1. 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; andan 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.