A GaAs Power Detector Design for $C$ -Band Wideband Complex Cross Correlation Measurement

Autor: Anyong Hu, Jungang Miao, Chen Chen, Ghulam Mehdi, Umar Dilshad, Chao Wang
Rok vydání: 2020
Předmět:
Zdroj: IEEE Transactions on Instrumentation and Measurement. 69:5673-5683
ISSN: 1557-9662
0018-9456
DOI: 10.1109/tim.2019.2957894
Popis: The design and measurement of a power detector circuit based on the 0.15- $\mu \text{m}$ GaAs pHEMT technology and its usage in complex cross correlation measurement are presented in this article. The six-port technology is employed for the calculation of the cross correlation, and the design equations from the requirements of the correlation measurement are provided to guide the power detector design. The relation between the signal-to-noise ratio (SNR) of the correlation results and the load resistor is deduced, which can restrict the resistor value choice for an acceptable SNR. By properly choosing the load resistor and the biasing of the transistor, a power detector circuit is designed with a suppressed output dc voltage variation resulting from the statistic feature of monolithic microwave integrated circuit (MMIC) production. A fabricated detector chip has been mounted onto a printed circuit board and has been characterized. The measurement results show a flat responsivity over 3.5–8 GHz and a 3-nV/ $\sqrt {\mathrm{ Hz}}$ output noise voltage spectrum. The complex cross correlation measurement is implemented using two power detector modules with carefully chosen bias currents. Across the frequency range of 3.5–8 GHz, the measured correlation circles have an amplitude imbalance of 3.5 dB and an axial ratio from 0.85 to 1.15. With an input power of −5 dBm, the measured SNR of the correlator output is above 26 dB.
Databáze: OpenAIRE