a digital look-up table adaptive predistortion technique using a six-port receiver for power amplifier linearization is presented. the system is designed in ka-band for a dvb-s2 satellite link. we use a six-port receiver at the linearizationloop in place of classic heterodyne receivers. the six-port receiver is implemented by the use of passive microwavecircuits and detector diodes. this approa...

In this paper, an lateral diffused metal–oxide– semiconductor-based very high-frequency class-E power amplifier has been investigated theoretically and experimentally. Simulations were verified by amplifier measurements and a record-high class-E output power was obtained at 144 MHz, whic is in excellent agreement with simulations. The key of the results is the use of efficient device models, si...

PURPOSE To assess the effectiveness of a keratoconus-detection algorithm derived from Artemis very high-frequency (VHF) digital ultrasound (ArcScan Inc., Morrison, CO) epithelial thickness maps in the fellow eye from a series of patients with unilateral keratoconus. METHODS The study included 10 patients with moderate to advanced keratoconus in one eye but a clinically and algorithmically top...

Vegetative hyphal fusion (VHF) is a ubiquitous phenomenon in filamentous fungi whose biological role is poorly understood. In Neurospora crassa, the mitogen-activated protein kinase (MAPK) Mak-2 and the WW domain protein So are required for efficient VHF. A MAPK orthologous to Mak-2, Fmk1, was previously shown to be essential for root penetration and pathogenicity of the vascular wilt fungus Fu...

Mild Lewis acids enhance the rate of the thermal conversion of vinylheptafulvene (VHF) to dihydroazulene (DHA). In the absence of light, stronger Lewis acids promote the otherwise photoinduced DHA to VHF conversion.

We report simultaneous meteor echo observations using the Arecibo 430MHz and 46.8-MHz radars. Using identical data-taking and meteor selection criteria, 1868 and 367 meteors were found in the 430-MHz and 46.8-MHz beams, respectively, while 145 were found in both beams during the 7 hours of observation. Of the 367 VHF echoes, there were only 10 trail echoes, while the rest were head echoes, whic...

Background. Viral hemorrhagic fevers (VHF) are a group of systemic diseases characterized by fever and bleeding, which have posed a formidable potential threat to public health with high morbidity and mortality. Traditional Chinese Medicine (TCM) formulas have been acknowledged with striking effects in treatment of hemorrhagic fever syndromes in China's history. Nevertheless, their accurate mec...

BACKGROUND Viral hemorrhagic fevers (VHF) are acute diseases associated with bleeding, organ failure, and shock. VHF may hardly be distinguished clinically from other diseases in the African hospital, including viral hepatitis. This study was conducted to determine if VHF and viral hepatitis contribute to hospital morbidity in the Central and Northern parts of Ghana. METHODOLOGY/PRINCIPAL FIN...

In this paper we describe an European initiative aiming to establish a broadband Very High Frequency (VHF) aeronautical communications system based on a multi-carrier technology and demonstrate its benefits to the aeronautical community, together with its technological fundamentals. The European research project B-VHF (“Broadband VHF Aeronautical Communications System based on Multi-Carrier Tec...