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Digital TV by Terrestrial Transmitters
Published in Lars-Ingemar Lundström, Understanding Digital Television, 2012
Figure 6.3 shows the frequency ranges for terrestrial TV. Band II 87– 108 MHz is used for FM radio while band III, 164–230 MHz includes channels 5, 6, 7, 8, 9, 11 and 12. During the 1960s, most countries in Europe wanted to start a second channel. Since the national TV stations had a monopoly in almost all European countries, the development of private TV was restricted and the number of channels was small. It took some time before the UHF frequency bands were brought into operation. In the UHF frequency bands, 470–862 MHz, there are much more bandwidth including channels 21–68.
Vibrational spectroscopy of free di-manganese oxide cluster complexes with di-hydrogen
Published in Molecular Physics, 2023
Sandra M. Lang, Thorsten M. Bernhardt, Joost M. Bakker, Bokwon Yoon, Uzi Landman
Thus, we conclude that the IR-MPD spectra of Mn2O4H2+ and Mn2O4D2+ with the observed isotope shift (bands α and β) are best described by isomer A. However, this isomer cannot account for the experimental bands i and ii. These bands appear upon hydrogen adsorption (cf. Figure 3) but do not show any isotope shift (cf. Figure 2), that is, they cannot involve motions that are dominated by the hydrogen atoms. Although band ii might potentially be explained by features of isomer B and B’ (but these isomers are unlikely to be present in considerable amount), the triad i cannot be explained by any of the studied isomers. Since, however, this triad bears some similarity to band II, it is reasonable to assign these bands to a combination of band II with the low frequency band IV. Both bands are also present in the spectrum of the bare Mn2O4+ cluster and are thus independent of H2. The observation of these combination bands in the spectrum of the hydrogen complexes but not in the spectrum of the bare cluster might be attributed to the presence of a rather weakly bound H2 (D2) molecule (binding energy of 0.42 eV) which makes it a good leaving group, allowing less intense features to become visible. Finally, band ii might also arise from a combination of band III with another low frequency mode.
Synthesis, characterization, electrochemistry, antioxidant, and toxicological studies of Co(II), Ni(II) and Ag(I) complexes of mefenamic acid/tolfenamic acid bearing metronidazole
Published in Journal of Coordination Chemistry, 2021
Nathaniel J. Shamle, Adedibu C. Tella, Adrian C. Whitwood, Anofi O.T. Ashafa, Peter A. Ajibade
Three low-intensity bands were observed in the visible region of the spectra for 2 which are assignable to d-d transitions. Precisely, three spin-allowed transitions are typical of Ni(II) complexes in an octahedral environment due to free ion ground 3F term and the excited 3P term. The assignments are: band I at 701 nm (14,265 cm−1) may be ascribed to a 3A2g (F) → 3T2g (F) transition, band II located at 580 nm (17, 241 cm−1) may be attributed to 3A2g (F) → 3T1g (F) transition and band III found at 411 nm (24,331 cm−1) may be assigned to 3A2g (F) → 3T1g (P) transition. Again, the fourth band in the UV region 313 nm (31949 cm−1) is attributed to charge transfer transition. The existence and location of the three bands assigned to d-d transitions are typical of distorted octahedral Ni(II) complexes [21], therefore a distorted octahedral geometry is proposed for 2.
Reconfigurable radio receiver with fractional sample rate converter and multi-rate ADC based on LO-derived sampling clock
Published in International Journal of Electronics, 2018
Sungkyung Park, Chester Sungchung Park
The sampling clock generator which functions as a frequency divider and buffer is needed between the LO and the clock input to the delta-sigma ADC. In the first place, a multiple of LO frequency ranges are considered for UTRA/FDD cellular bands: ×2 LO for band I (2110–2170 MHz) corresponds to 4220–4340 MHz, ×2 LO for band II corresponds to 3860–3980 MHz, ×2 LO for band III corresponds to 3610–3760 MHz, ×2 LO for band IV corresponds to 4220–4310 MHz, ×4 LO for band V (869–894 MHz) corresponds to 3476–3576 MHz, ×4 LO for band VI corresponds to 3500–3540 MHz, ×4 LO for band VIII corresponds to 3700–3840 MHz, ×2 LO for band IX corresponds to 3690–3760 MHz. For each of these bands, appropriate choice between divide-by-12 or divide-by-14 logic for the sampling clock generator determines the frequency range of the ADC clock input. For band I, for example, divide-by-14 logic makes the frequency range of the ADC clock input 301–310 MHz and for band II divide-by-12 logic makes the frequency range 322–332 MHz. The common frequency range covering all of these bands is 290–332 MHz. Similarly, ×2 or ×4 LO for band VII, DCS 1800 band, PCS 1900 band, E-GSM 900 band and GSM 850 band with appropriate choice between divide-by-12 or divide-by-16 logic determines the frequency range of the ADC clock input. The common frequency range covering all the five bands is 289–337 MHz.