TY - JOUR
T1 - Design and Validation of A Multi-link Phase-Compensated Long-Range Ultrawideband VNA-based Channel Sounder
AU - Lyu, Yejian
AU - Mbugua, Allan Wainaina
AU - Yuan, Zhiqiang
AU - Olesen, Kim
AU - Fan, Wei
PY - 2022/10/1
Y1 - 2022/10/1
N2 - This article presents a novel and cost-effective vector network analyzer (VNA)-based phase-compensated channel sounder operating in the frequency range of 10-50 GHz using radio-over-fiber (RoF) techniques, which can support multilink/channel long-range phase-coherent measurements. The optical cable enables long-range channel measurements with a dynamic range of 115.7 dB at 30 GHz (for the back-to-back connection). The phase compensation scheme is utilized for stabilizing the inherent phase variations introduced by the optical fiber of the channel sounder to enable its application in multichannel/antenna measurements. A novel optical delay line and combiner scheme is proposed and implemented to separate the signals, thereby saving the port resource on the VNA for multilink/channel measurements. The proposed channel sounder is validated in back-to-back measurements under two optical cable conditions, i.e., with the presence of thermal changes and mechanical stress. The phase change could be maintained within 3° at 10-30 GHz and 7° in 30-50 GHz compared to the over 80° phase variation introduced by the cable effects at 10-50 GHz, demonstrating the robustness and effectiveness of the developed channel sounder in practice. With the proposed optical delay line and combiner scheme, multiple channels can be measured simultaneously with minimal VNA ports, significantly reducing the measurement cost and time for multilink channel measurements. Two multilink indoor channel measurements are conducted and analyzed using a virtual uniform rectangular array (URA) at 28-GHz bands. The results demonstrate the capability of the proposed channel sounder to perform high-fidelity long-range ultrawideband multilink channel measurements.
AB - This article presents a novel and cost-effective vector network analyzer (VNA)-based phase-compensated channel sounder operating in the frequency range of 10-50 GHz using radio-over-fiber (RoF) techniques, which can support multilink/channel long-range phase-coherent measurements. The optical cable enables long-range channel measurements with a dynamic range of 115.7 dB at 30 GHz (for the back-to-back connection). The phase compensation scheme is utilized for stabilizing the inherent phase variations introduced by the optical fiber of the channel sounder to enable its application in multichannel/antenna measurements. A novel optical delay line and combiner scheme is proposed and implemented to separate the signals, thereby saving the port resource on the VNA for multilink/channel measurements. The proposed channel sounder is validated in back-to-back measurements under two optical cable conditions, i.e., with the presence of thermal changes and mechanical stress. The phase change could be maintained within 3° at 10-30 GHz and 7° in 30-50 GHz compared to the over 80° phase variation introduced by the cable effects at 10-50 GHz, demonstrating the robustness and effectiveness of the developed channel sounder in practice. With the proposed optical delay line and combiner scheme, multiple channels can be measured simultaneously with minimal VNA ports, significantly reducing the measurement cost and time for multilink channel measurements. Two multilink indoor channel measurements are conducted and analyzed using a virtual uniform rectangular array (URA) at 28-GHz bands. The results demonstrate the capability of the proposed channel sounder to perform high-fidelity long-range ultrawideband multilink channel measurements.
KW - Antenna measurements
KW - Bandwidth
KW - Channel sounding
KW - Costs
KW - Delay lines
KW - Frequency measurement
KW - Optical variables measurement
KW - Phase measurement
KW - millimeter wave (mmWave)
KW - multilink
KW - phase compensation
KW - radio-over-fiber (RoF)
UR - http://www.scopus.com/inward/record.url?scp=85136007030&partnerID=8YFLogxK
U2 - 10.1109/TMTT.2022.3194045
DO - 10.1109/TMTT.2022.3194045
M3 - Journal article
SN - 0018-9480
VL - 70
SP - 4528
EP - 4543
JO - I E E E Transactions on Microwave Theory and Techniques
JF - I E E E Transactions on Microwave Theory and Techniques
IS - 10
ER -