Terrestrial DTV Receiving Antenna with Signal Level Indicator

• Main Authors: Lin,Mao-Jung, 林茂榮
• Other Authors: Lin,Der-Yuh
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/3quysu

碩士 === 國立彰化師範大學 === 電子工程學系 === 105 === The evolution of terrestrial TV broadcast switched from analogue to digital is in an all-round manner. Not only the behavior of user is changed, also the scenario of user is quite different. For example, in analogue time, outdoor antenna is primary, indoor antenna is secondary, at digital era, it is reversed, indoor antenna is primary. Due to receiving terrestrial analogue TV failure mode is snowing, and people might be ignored or endured. However receiving terrestrial digital TV failure mode is completely loss of picture and/or sound. Who can endure this extremely annoyance? So it impact more severely on the consumer experience of digital than analogue television. Its mean digital mode more depend on performance of receiving antenna, but both, analogue and digital, are facing a difficulty of high return rate issue noted and this is confusing for some. It is very important a design with economical technology to provide enough ability of signal level indicator for terrestrial TV receiving antenna. This not only could settle high return rate but also provide friendly set-up of DTV antenna. Here start from analyzing the failure mode of terrestrial TV receiving and focusing difficulty of root-cause, then do some basic pilot study and test for verifying this proposal of addressing a terrestrial DTV receiving antenna with signal level indicator is workable. DTV antenna is at front-end and independent of receiving system. There is not available of base band as IF of general super heterodyne receiver. Antenna element pick up the signals follow a UHF band-pass filter stopping all other than DTV signal. After an LNA to boost DTV signals, simple RF detector with RF detector to transfer RF signal level as to related DC voltage. A MCU building-in ADC sampling DC output voltage of RF detector. Firmware with very simple algorithm to control I/O pins of MCU to lit LED as indicating signal strength. Arrange colors and numbers of LED for signal level indicating to achieve user intuitively and friendly. Key word:DTV