In conventional phase noise metrology, the phase noise of an oscillator is measured by instruments equipped with specialized and sophisticated devices. Such hardware-based testing usually requires high-performance and costly apparatuses. In this paper, we carried out a novel phase noise measurement method based on a mathematical model. The relationship between the phase noise of a radio frequency oscillator and its power spectral density (PSD) was established, different components of the power law phase noise were analyzed in the frequency domain with their characteristic parameters. Based on the complete physical model of an oscillator, we fitted and extracted the parameters for the near-carrier Gaussian and the power law PSD with Levenberg-Marquardt optimization algorithm. The fitted parameters were used to restore the power law phase noise with considerable precision. Experimental validation showed an excellent agreement between the estimation from the proposed method and the data measured by a high-performance commercial instrument. This methodology can be potentially used to realize fast and simple phase noise measurement and reduce the overall cost of hardware.
The letter presents a high-performance doubly balanced ring mixer (DBRM) fabricated by a 0.1 µm GaAs pHEMT process that achieves ultrawide radio-frequency (RF) and intermediate frequency (IF) bandwidths. A multiple-coupled-line Marchand balun is optimized to extend the RF bandwidth. A novel structure is designed to directly extract the IF current from the RF balun without an additional IF coupler. Due to the proposed IF extraction structure, the IF bandwidth is broadened with decreased complexity. The size of the whole chip including the probe GSG pads is 0.95×0.65 mm 2 . The measured results show that the conversion loss is 7.2-11.9 dB for the RF frequency range of 35-95 GHz with an LO power level of 14 dBm and a fixed IF frequency of 1 GHz. In addition, the conversion loss is better than 12 dB for the IF frequency range from DC to 30 GHz under a fixed LO frequency. key words: ultrawide bandwidth, doubly balanced ring mixer (DBRM), Marchand balun, monolithic microwave integrated circuit (MMIC) Classification: Microwave and millimeter-wave devices, circuits, and modules
A flexible mechanical deformation test system, which is a combination of the microwave and the flexible film, is proposed. The system consists of a U-shaped microwave resonator, coaxial transmission line, and PDMS flexible substrate. Microwave signals are generated from the vector network analyzer and loaded to the coaxial transmission line and then coupled to the U-shaped resonator through the coupling loop. The resonator works at the gigahertz band with the test range from 3 GHz to 40 GHz. The resonant frequency of the resonator can be adjusted by changing the shape of PDMS, and the related signals can be detected by using the S11 parameter of the microwave. The response time of the U-shaped resonator is less than 20 ms, and the sensitivity on the curved surface is 12.5 Hz/nm.
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