Yongjiu Zhao

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A novel approach to generating an ultraflat and stable optical frequency comb with tunable frequency spacing is proposed and experimentally demonstrated. The proposed generator consists of a polarization modulator (PolM) and a polarizer. The joint operation of a PolM and a polarizer is equivalent to intensity modulation, but with a third controllable(More)
In this paper, an ultra-wideband and polarization-independent metasurface for radar cross section (RCS) reduction is proposed. The unit cell of the metasurface operates in a linear cross-polarization scheme in a broad band. The phase and amplitude of cross-polarized reflection can be separately controlled by its geometry and rotation angle. Based on the(More)
In this paper, a general synthesis method is proposed for the design of multi-frequency impedance transformers (MFITs) for arbitrary frequency-dependent complex loads (FDCLs) by adopting the concept of multi-frequency inverters (MFIs). An MFI, which is placed between two susceptance blocks, is constructed with a transmission line and two-side(More)
In this work, we explore the existence of multiband localized spoof plasmons (LSPs) in closed textured cavities with multiple groove depths. It is interesting to note that the spoof LSPs in each band resemble those generated by the textured 2D cavities of the same periodicity with the corresponding single groove depth, and the field distributions and(More)
A comprehensive study of the optical single-sideband (OSSB) modulation based optical vector network analyzer (OVNA) is performed to reveal the origination of the measurement error. By applying stimulated Brillouin scattering (SBS) in an 8-km single-mode fiber (SMF) as the device-under-test (DUT), and employing an optical processor to control the high-order(More)
This paper presents formulae of the residual errors of S-parameter measurements derived for multiport vector network analyzers (VNAs) calibrated by non-ideal TRM (Through-Reflect-Match) calibration standards. Using the concepts of general error terms and general nodes, the generalized error correction equation for multiport VNA measurements based on 4N-term(More)
A novel optical vector network analyzer (OVNA) based on optical single-sideband (OSSB) modulation and balanced photodetection is proposed and experimentally demonstrated, which can eliminate the measurement error induced by the high-order sidebands in the OSSB signal. According to the analytical model of the conventional OSSB-based OVNA, if the optical(More)
ELECT Accurate measurement of the optical magnitude and phase responses based on optical single-sideband (OSSB) modulation with doubled measurement range is proposed and demonstrated. In the scheme, an optical carrier and a second-order sideband are generated by an RF signal at an OSSB modulator consisting of a Mach–Zehnder modulator and an optical bandpass(More)