A vector method for determining voltage standing wave ratio of radio communication

This paper introduces a vector method for determining Voltage Standing Wave Ratio (VSWR) in wireless base station system, comprising: a hardware circuit design and a soft computing theory. The VSWR detection is divided into two parts, calibration and verification. In the calibration process, the S parameters of three known loads are obtained by vector network analyzer. In the verification process the standing wave of the antenna is calculated from the vector operation by the known S parameters and the PA´s return loss. The obvious advantage of this type of structure is that the detection result is the real VSWR at antenna feeder port and the accuracy is higher than existing technology. In this paper, the hardware implementation of the standing wave detection is introduced firstly, then a vector algorithm and software realization is proposed, furthermore the above algorithm is simulated in ADS, finally the above algorithm is verified in test bench. The test result shows that the detection error is within 0.2 when the antenna VSWR is 2.