Sökning: "wideband"

Visar resultat 11 - 15 av 183 avhandlingar innehållade ordet wideband.

  1. 11. Ultra-wideband synthetic aperture radar in the VHF-band: Image formation algorithms and interferometric applications

    Författare :Per-Olov Frölind; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; backprojection; wideband; VHF; DEM; SAR; CARABAS; signal processing; low frequency; interferometry;

    Sammanfattning : Synthetic aperture radar (SAR) is a technology to generate high-resolution radar images for ground surveillance and mapping. By exploiting the lower VHF band, the attenuation reduces dramatically in forest areas compared to microwaves and new applications become feasible. LÄS MER

  3. 12. Wideband Sigma-Delta Modulators

    Författare :Xiaolong Yuan; Svante Signell; Jakob Wikner; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sigma-delta modulator; feedforward; reconfigurable; quadrature bandpass filtering; Electronics; Elektronik;

    Sammanfattning : Sigma-delta modulators (SDM) have come up as an attractive candidatefor analog-to-digital conversion in single chip front ends thanks to the continuousimproving performance. The major disadvantage is the limited bandwidthdue to the need of oversampling. LÄS MER

  4. 13. Wideband integrated circuits for optical communication systems

    Författare :Stavros Giannakopoulos; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; optical interconnects; SiGe HBT; receiverfront-end; VCSEL driver; wideband amplifiers; data communication; InP DHBT; TIA; distributed amplifiers.;

    Sammanfattning : The exponential growth of internet traffic drives datacenters to constantly improvetheir capacity. Several research and industrial organizations are aiming towardsTbps Ethernet and beyond, which brings new challenges to the field of high-speedbroadband electronic circuit design. LÄS MER

  5. 14. Ultra-wideband Antenna and Radio Front-end Systems

    Författare :Magnus Karlsson; Anders Rydberg; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wireless communication; ultra-wideband; radio communication; UWB bandwidth; antenna parallelism; Electrical engineering; Elektroteknik;

    Sammanfattning : The number of wireless communication applications increase steadily, leading to the competition for currently allocated frequency bands. Pressure on authorities around the world to permit communications in higher and wider frequency ranges to achieve higher wireless capacity than those existed in the past has resulted in several new specifications. LÄS MER

  7. 15. Ultra wideband microwave hyperthermia for brain cancer treatment

    Författare :Massimiliano Zanoli; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ultra wideband; treatment planning; brain cancer; applicator design; time reversal; microwave hyperthermia;

    Sammanfattning : Despite numerous clinical trials demonstrating that microwave hyperthermia is a powerful adjuvant modality in the treatment of cancers, there have been few instances where this method has been applied to brain tumors. The reason is a combination of anatomical and physiological factors in this site that require an extra degree of accuracy and precision in the thermal dose delivery. LÄS MER