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Special issue on Surveillance Systems for Air Navigation Services
Wideband and wide-angle flat Radomes using dielectric and ferrite layers
A new structure is proposed in this article, to operate as wideband and wide-angle flat Radome. In this structure several dielectric and ferrite layers are placed successively, one next to the other, to behave as a matched layer. First, the relationship between the permittivity and permeability of a required fictitious mixed material is obtained. Then the required permittivity and permeability of
Wideband and wide-angle flat Radomes using dielectric and ferrite layers
A new structure is proposed in this article, to operate as wideband and wide-angle flat Radome. In this structure several dielectric and ferrite layers are placed successively, one next to the other, to behave as a matched layer. First, the relationship between the permittivity and permeability of a required fictitious mixed material is obtained. Then the required permittivity and permeability of
Technology developments for a large-format heterodyne MMIC array at W-band
We report on the development of W-band (75?110 GHz) heterodyne receiver technology for large-format astronomical arrays. The receiver system is designed to be both mass producible, so that the designs could be scaled to thousands of receiver elements, and modular. Most of the receiver functionality is integrated into compact monolithic microwave integrated circuit (MMIC) amplifier-based multichip
Wireless space-division-multiplexed signal discrimination device using electro-optic modulator with antenna-coupled electrodes and polarization-reversed structures
Millimeter-wave wireless space-division-multiplexing signals were discriminated by a newly developed electro-optic modulator using an array of antenna-coupled electrodes and polarization-reversed structures of ferroelectric optical crystals. Discrimination with channel isolation over 13 dB was obtained for two 38 GHz wireless signals with an irradiation angle difference of 15° by use of a fabricat
Advanced characterization of a W-band phase shifter based on liquid crystals and MEMS technology
In this paper, we present a continuously tunable phase shifter realized in MEMS technology. Varactors with liquid crystal as a tunable dielectric layer underneath gold bridges are used to build a loaded line phase shifter. Measurements show that the phase shifter has a differential phase shift of 92°, a figure of merit (FoM) of 42°/dB and an input matching of ?19 dB at 76 GHz.The tuning speed of t
New pulsed measurement setup for GaN and GaAs FETs characterization
A new setup is proposed for the measurement of current?voltage pulsed characteristics of electron devices. The main advantages of the system consist in: shorter pulse widths through generation in a 50-? environment, simple average current monitoring through separation of the direct and alternate current paths, setting of average voltage values independently of pulse amplitudes and duty cycle, and
A 120 GHz FMCW radar frontend demonstrator based on a SiGe chipset
This paper presents a frequency-modulated continuous-wave (FMCW) radar operating at 120 GHz, which features silicon?germanium (SiGe) chips that employ HBTs with 320 GHz f. The chipset comprises a fundamental-wave signal-generation chip with a voltage-controlled oscillator (VCO) that provides frequencies between 114 and 130 GHz and a corresponding dual?transceiver (TRX) chip that supports monostati
A time domain transmission measurement system for dielectric characterizations
Delay time measurements are a commonly used technique for the characterization of dielectric materials. Especially with regard to the characterization of water?solid mixtures like soil or grain delay time measurements, e.g., time domain reflectometry offers a powerful method. However, the accuracy of reflection measurements is limited due to multiple reflections caused by inhomogenities of the env