Apparatus and method for communication relay apparatus and the standing wave ratio detector

The invention discloses a communication relay device and a standing-wave ratio detection device and a corresponding detection method thereof. The standing-wave ratio detection device comprises a coupler, a time slot switch, a power divider, a power detecting tube, an analog-to-digital converter and a calculation unit, wherein the coupler couples a path of transmitted power signals amplified by a closed loop power control unit; the time slot switch correspondingly gates a reflected power signal of an uplink of an antenna port and the coupled transmitted power signals according to the uplink and downlink time slots of a communication system; the power divider equally distributes the power signals gated by the time slot switch to the power detecting tube and a feedback frequency-variable link of the closed loop power control unit; the power detecting tube converts the power signals into corresponding voltage signals; the analog-to-digital converter converts the voltage signals in an analog format into voltage signals in a digital format; and the calculation unit calculates the return loss of the antenna port by using reflected voltage signals in the digital format and transmitted voltage signals in the digital format so as to determine a standing-wave ratio value. The standing-wave ratio detection device detects a standing-wave ratio through a simple circuit at low cost, and is particularly suitable for a wideband communication system.