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Types of Broadcasting
Published in Skip Pizzi, Graham A. Jones, A Broadcast Engineering Tutorial for Non-Engineers, 2014
MediaFLO (also known as FLO TV) was developed by Qualcomm to transmit TV, audio, and data primarily to mobile phones. The service was considered by several wireless telecommunications companies in the United States, and initially offered by some, but in 2011, MediaFLO service was terminated, ending further development and deployment of the service. Although it targeted phone-based receivers, the system provided transmission of content from a transmitter to receiver in a one-way mode, and hence the name “FLO”—Forward Link Only. MediaFLO in the United States was transmitted by a network of high-power broadcast transmitters that had previously been operated as broadcast UHF TV channels 55 and 56. Transmissions were encrypted and used OFDM with QAM or quadrature phase-shift keying (QPSK) modulation. Video resolution was 240 lines × 320 pixels, which is known as the quarter video graphics array standard (QVGA).
A prototype active-matrix OLED using graphene anode for flexible display application
Published in Journal of Information Display, 2020
O Eun Kwon, Jin-Wook Shin, Himchan Oh, Chan-mo Kang, Hyunsu Cho, Byoung-Hwa Kwon, Chun-Won Byun, Jong-Heon Yang, Kang Me Lee, Jun-Han Han, Nam Sung Cho, Jong Hyuk Yoon, Seung Jin Chae, Jin Sung Park, Hyunkoo Lee, Chi-Sun Hwang, Jaehyun Moon, Jeong-Ik Lee
In the past, these researchers successfully demonstrated passive-matrix-type organic light-emitting diode (OLED) panels with pixelated graphene films as transparent electrodes. To be specific, fully functional Gen 2(370 × 470 mm)-sized and flexible graphene anode OLEDs were demonstrated. With the aim of developing fully functional flexible AM-graphene OLED panels, the relevant technical issues were presented, and associated solutions were suggested, both on the integration and component levels. The importance of graphene film fine patterning and the use of the laser lift-off technology for realizing flexible panels on a realistic-sized substrate was emphasized. For demonstration purposes, an active-matrix OLED (AMOLED) panel with a QVGA (320 × 240) resolution and a 2T-1C per-pixel scheme was prepared. On a PI/glass support, an oxide thin-film transistor (TFT) array, a planarization layer, and a pixelated graphene array were sequentially formed. The fabrication steps are compatible with those of the existing display processes. It is believed that the proposed approach suggests a meaningful advancement in realizing the ultra-thin flexible display, in which the unique properties of graphene are crucial.