Reduction of Crosstalk Between Dual Power Amplifiers Using Laser Treatment

Abstract

A cost-effective isolation technique using laser treatment is proposed to suppress the undesired crosstalk between dual power amplifiers (PAs), which are essential to multiple-input multiple-output communications system. Laser treatment not only reduces the small-signal coupling between dual PAs but also enhances the linearity of the PA under dual-PA operation mode. The figure of merit for the small-signal coupling has an improvement of 4.55 dB at 2.45 GHz, and the output power at 3% ( 30 dB) error vector magnitude (EVM) has a linearity improvement of 6.1 dB under 0-dB interference.Index Terms-Coupling, crosstalk, isolation, laser treatment, multiple input multiple output (MIMO), power amplifiers (PAs).

Tuning the Intramolecular Charge Transfer Emission from Deep Blue to Green in Ambipolar Systems Based on Dibenzothiophene S,S-Dioxide by Manipulation of Conjugation and Strength of the Electron Donor Units

“…Analogous 2,8-disubstituted (bent) S units with both DPA and TPA substituents (without butyl chains) have been previously reported; 22 they exhibit blue-shifted emission in toluene compared with 23 and 26, indicating similar bent vs linear effects. A similar effect was reported by Estrada and Neckers for trimers with the fluoren-9-ylidene malonitrile acceptor at the core: for the linear trimer the HOMO was delocalized, whereas for the bent isomer the HOMO was predominantly localized on the donor units.…”

“…21 Ambipolar molecules comprising disubstituted S units as the acceptor moiety and diphenylamine/triphenylamine donor moieties have also been studied. 22 The present work describes new ambipolar oligomers containing S as the core unit. The objective is to tune the emission properties by combining the strategies of conjugation control (by systematically changing the substitution pattern between donor and acceptor) and varying the redox potential of the donor unit: namely, carbazole (Cz), di-/triphenylamine (DPA, TPA), and fluorene (F).…”

Theoretical Study on Photophysical Properties of Ambipolar Spirobifluorene Derivatives as Efficient Blue-Light-Emitting Materials

“…1 By tailoring the nature of the substituents and their substitution patterns about the 9,9′-spirobifluorene unit, for example, with an identical or different biphenyl branch, 2,3 it is easy to manipulate the electronic structure, emission spectrum, thermal/ morphological stability, or charge carrier mobility of 9,9′spirobifluorene-based materials. Moreover, with developing emitters equipped with an appropriate electron donor (D) that facilitates hole injection and/or transport and an electron acceptor (A) that improves electron injection and/or transport, 4 it is promising to balance the electron-hole recombination efficiency, to control the levels of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) as well as the emission color to a fine degree, [5][6][7][8] making such systems increasingly attractive for use in singlelayer OLEDs. [9][10][11] However, the 9,9′-spirobifluorene derivatives featuring donors on one biphenyl branch spiro-linked to another biphenyl moiety bearing acceptors exhibit low photoluminescence efficiencies as a result of strong photoinduced electron transfer.…”

A m-Terphenyl-Modifed Sulfone Derivative as a Host Material for High-Efficiency Blue and Green Phosphorescent OLEDs

“…In this regard, a sulfone-containing material is an attractive candidate to present a great opportunity for a phosphorescent host material, because a sulfone moiety possesses a strong electron-accepting nature. Some sulfone-containing materials have been used as an emitter and an electron transporter to realize high-performance fluorescent OLEDs so far. On the other hand, Hsu and co-workers have reported triphenylamine/bisphenylsulfonyl-substituted fluorene material for red phosphorescent OLEDs .…”