L band

About: L band is a research topic. Over the lifetime, 674 publications have been published within this topic receiving 4570 citations.

A Broadband Active Quasi Circulator for UHF and L Band Applications

Abstract: This letter presents a compact, broadband three-port MMIC-based quasi circulator for UHF and L bands. As a motivation and application, the use of this circuit in a network analyzer is presented. The circuit is designed using differential amplifier and lossy broadband combiner to obtain effective phase cancellation for high directivity. The designed quasi circulator has return losses at all ports better than 10 dB and reverse isolation above 30 dB in the frequency range from 0.2 to 2.5 GHz. The quasi circulator has directivity of 15 to 52 dB and load dynamic range of 10 to 49 dB, over the 0.2 to 1.7 GHz band. The proposed circuit thus can be used in portable network analyzers and other applications designed for the UHF and L bands.

Backscatter Distributions of Persistent and Distributed Scatterers Over Wavelength: Results From X -, C -, and L -Band

Abstract: Persistent scatterer (PS) techniques are a set of important time-series tools for interferometric synthetic aperture radar (InSAR) that enable deformation analysis in highly decorrelated terrain. Detailed knowledge of the statistics of persistent scatterers in InSAR images is critical for the design of better techniques that will enable both the extraction of deformation in traditionally difficult regions as well as develop a better understanding of how performance of these algorithms relates to important system parameters. In this article, we characterize the backscatter statistics of both persistent and distributed scatterers over wavelength using data from X -band (COSMO-SkyMed), C -band (Sentinel-1), and L -band (ALOS) sensors. We show that popular distributions that have previously been used to fit SAR backscatter can effectively capture the returns from both PS and clutter, with the $\text {G}^0$ distribution being the most applicable across wavelength and scatterer type. Thus, our work paves the way for improved detection algorithms to be designed based on these distributions and also builds an initial foundation for developing a greater theoretical understanding of PS statistics.

Satellite L-band output multiplexer utilizing single and dual mode dielectric resonators

Abstract: A four-channel, contiguous-band output multiplexer for L-band satellite applications is described. The filters feature single- and dual-mode dielectric resonators and operate at power levels up to 13 W in vacuum. The design of the multiplexer was optimized to meet different requirements for each of the filters. Excellent electrical performance in a relatively small package was obtained by use of high-performance dielectric resonators and a coaxial line combiner. >

Characteristic of mobile satellite l-band signal in mid-latitude region:GPS approach

Abstract: Mobile satellite L-band signal that propagates from the transmitting satellite to the receiver experiences impairment mainly due to shadowing and multipath effects. In the present study, open space data has been obtained for Fukuoka, Japan (mid-latitude) using portable global positioning system (GPS) satellite receiver. The received signal performance, fading characteristic and cumulative distribution function of certain GPS satellites over the sky of Fukuoka have been observed and analysed. A general mathematical model representing the signal strength for the open space environment has been deduced based on the collected data. The outcome of this study can be used in future research to determine the effect of different mobile satellite environment on the arriving mobile satellite signal in improving the quality of service perceived by mobile satellite users.