Cable loss is a factor to be considered in system design. The loss introduced by the cable varies with frequency. Mobile Mark has tested some of the cables that we use in our designs, and the measured results have been plotted against frequency. This gives the system designer an easy way to determine the actual loss introduced by the cable in the overall system. It is to be noted here that these results, as mentioned above, are measured results, so a more practical indication of cable performance versus frequency can be obtained from these plots. The losses are given as dB/100 ft; so the actual length of the cable in the system needs to be used to convert the value from the graph into the loss introduced by the cable in the system. Another thing to be noted is that the measurements have been performed using SMA connectors at the ends of the cable assembly.
| Loss per Foot | ||||
|---|---|---|---|---|
| Common Cable Type | 900 MHz | 2,000 MHz | 2,500 MHz | 5,000 MHz |
| RG-174 | 0.32 dB | 0.49 dB | 0.50 dB | NOT Recommended |
| RG-58 | 0.14 dB | 0.21 dB | 0.24 dB | 0.43 dB |
| RF-195 | 0.10 dB | 0.15 dB | 0.17 dB | 0.25 dB |
| LMR-240 | 0.07 dB | 0.10 dB | 0.14 dB | 0.17 dB |
| LMR-400 | 0.04 dB | 0.06 dB | 0.07 dB | 0.12 db |
Cables come in various types and material. The Diameter generally effects the Antenna’s Performance. Thicker Cables have less loss ( less loss of energy), however, the longer the Cable is in Length, the increase in Cable Loss.
