Key parameters of power resistors include power rating, frequency, and Voltage Standing Wave Ratio (VSWR). Typical power ratings range from 10W to 500W. The telecom industry applications range from 10W to 250W while resistors used in broadcast applications are rated up to 800W. The frequency range of radio tends to stay around 200MHz – 300MHz, digital TV has a maximum of 1GHz, and cellular phone networks at 2GHz. The VSWR of a resistor is related to the reflection coefficient and is desired to be as close to unity as possible.  High power and high frequency circuits make it difficult to achieve a unity VSWR due to the large physical size of the resistor.