Current Issue : October - December Volume : 2015 Issue Number : 4 Articles : 5 Articles
Different types of bondwire interconnect for differential chip-to-antenna and single-ended chip-to-chip interfaces are investigated.\nTwo differential compensation structures for various lengths of interconnects are designed and experimentally evaluated\nusing dedicated transmit and receive radar modules operating across a 110ââ?¬â??156 GHz band. Measurement results\ndemonstrate that a fractional bandwidth of 7.5% and a minimum insertion loss of 0.2 dB can be achieved for differential\ninterconnects as long as 0.8 mm. Design and measurement results of an extremely wideband low-loss single-ended\nchip-to-chip bondwire interconnect that features 1.5 dB bandwidth from DC to 170 GHz and insertion loss of less than\n1 dB at 140 GHz are presented as well. The results show that the well-established wire-bonding techniques are still an attractive\nsolution even beyond 100 GHz. Reproducibility and scalability of the proposed solutions are assessed as well....
A fabrication method of the multi-wavelength fiber grating (FBG) was introduced. Using\nthe scan exposure method, the multi-wavelength FBG can be successfully manufactured through\napplying different tensile forces during the multiple exposures process on the same fiber. Experiment\nresults show that the position and the overlap of different sub FBGs will greatly affect the spectrum\nof every sub FBG. The spectrum of each sub FBG will be affected by short wave oscillation unless\nthe lengths and positions of all sub FBGs are fully overlapped. For hydrogen loaded fiber, the\nwavelength and reflectivity of the nth level FBG will increase as the (n+1)th level FBG is written.\nBut for germanium doped photosensitive fiber, multiple exposure will increase the wavelength of\nprevious sub FBGs while decrease the reflectivity of all sub FBGs. Through well distributing\nexposure intensity of every sub FBGs, a four-wavelength FBG with same sub FBG�s spectrum was\nfabricated on a hydrogen loaded single mode fiber....
Weak signal detection for single-mode fiber-optic distributed temperature sensor (DTS) is\na key technology to achieve better performance. A hybrid technique combining the incoherent optical\nfrequency domain reflectometry (IOFDR) and the three-channel simultaneous radio-frequency (RF)\nlock-in amplifier (LIA) is presented to improve the signal-to-noise ratio (SNR) of the measured\nspontaneous Raman backscattered light. The field programmable gate array (FPGA) based RF-LIA is\ndesigned with a novel and simple structure. The measurement frequency range is achieved from\n1 kHz to 100 MHz. Experimental results show that the backscattered light signal of picowatt level\ncan be detected with high SNR. With a 2.5 km single-mode fiber, a 1064 nm laser source, and the\nmeasurement time of 500 s, this sensing system can reach a spatial resolution of 0.93 m and a\ntemperature resolution of about 0.2.C....
A simple electromagnetic model of wind-turbine�s main structural elements as the linear wired structures is developed to\nsimulate the temporal patterns of observed radar return Doppler spectra (micro-Doppler). Using the model, the\nmicro-Doppler for different combinations of the turbines rotation frequency, radar pulse repetition frequency, and duration\nof the Doppler measurement interval are analyzed. The model is validated using the PARSAX radar experimental data. The\nmodel ability to reproduce the observed Doppler spectra main features can be used for development of signal-processing\nalgorithms to suppress the wind-turbines clutter in modern Doppler radars....
This article introduces the fabrication technology processes of the capacitive pressure\nsensor based on the low temperature co-fired ceramic (LTCC) material. Filling the cavity with\ndifferent materials as a sacrificial layer is mainly discussed, and two different materials are chosen in\nthe fabrication. It is found that the cavity filled with polyimide expands largely during sintering,\nwhile carbon ESL49000 material filled is more preferable to keep the cavity flat. Finally, the\nstructure leaving without an air evacuation channel is designed and tested in a built-up pressure\nenvironment, the frequency measured decreases approximately linearly with the pressure applied,\nwhich proves the design leaving no air evacuation channel advisable....
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