| dc.description.abstract | The goal of this work is the development of dual-band six-port receiver and direction of angle detector with compact size. The proposed miniaturized dual-band six-port network receiver front-end composed of a miniaturized dual-band six-port network, four power detectors, and two analog subtractors. It can be connected with the digital demodulation software to restore the digital modulated signal, or it can be used as a direction of angle (DOA) detector through proper calculation at the back end . The circuit size of the 2.45/5.94GHz six-port receiver is 53mm×48.5mm, which corresponds to an electrical size 0.39 λ0×0.36λ0 at f0 = 2.45GHz, or 0.87λ0×0.87λ0 at f0 = 5.94GHz. In order to achieve miniaturization and dual-band operateion at the same time, bridged-T coil is used to realize the dual-band power divider and the dual-band branch line coupler, and form a dual-band six-port network in the integrated passive device (IPD) process. The circuit size is only 5.85 mm×5.47 mm. The corresponding electrical size is around 0.0477 λ0× 0.0446 λ0 at 2.45 GHz and 0.113 λ0×0.105 λ0 at 5.8 GHz. At 2.45GHz, the measured insertion loss is 7.7±0.6 dB, the input and output reflection loss is greater than 16.7dB, and the phase difference is less than 2.9. At 5.94GHz, the measured insertion loss is 9±0.7 dB, the input and output reflection loss is greater than 17.3dB, and the phase difference is less than 7.2°.
The performance of the proposed six-port receiver is investigated with differenct modulation schemes including QPSK, 16-QAM and 64-QAM. At 2.45GHz, the dynamic range of QPSK modulation is -27.7 to -1.5dBm, the dynamic range of 16-QAM modulation is -30 to 2dBm, and the dynamic range of 64-QAM modulation is -27.7 to -1.7dBm. At 5.94GHz, the dynamic range of QPSK modulation is -24.15 to 2.15dBm, the dynamic range of 16-QAM modulation is -24.15 to 3.85dBm, and the dynamic range of 64-QAM modulation is -26.15 to 3.85dBm.
By connecting the input port of the six-port network to the two receiving antennas with a certain distance between them, a DOA detector can be realized. At 2.45GHz, the maximum angle error is at -60°with an error value of 3°, while the errors of other angles are less than 1.5°. | en_US |