更多信息 - 无线主页 - 应用笔记和技术讲座 - 评估板软件 - 技术支持   Abstract: This compact USB dongle design combines a MAX2165 direct-conversion tuner and a DMB-TH demodulator. The design converts a UHF signal (470MHz to 858MHz) to a MPEG-2 transport stream. Then the USB interface enables video viewing on a laptop or desktop computer. Figure 1. The reference design for the compact DMB-TH USB dongle features the MAX2165. More detailed image (PDF, 232kB) Figure 2. System block diagram. Lab Measurements MAX2165 Noise Figure and Maximum Gain Figure 3. The noise figure ranges from 3.0dB to 4.3dB, with maximum gain ranging from 79.2dB to 81.8dB over 474MHz to 858MHz. MAX2165 Phase Noise at 474MHz Figure 4. Phase noise at 1.0kHz offset is -99dBc/Hz when the LO frequency is 474MHz. RF Input Return Loss Figure 5. The input return loss is better than -7.7dB from 474MHZ to 858MHz when the LO frequency is 858MHz. Detailed Description This DMB-TH receiver reference design includes the MAX2165 direct-conversion tuner, a DMB-TH demodulator, and USB interface circuitry. This solution is intended for handheld or laptop computer-based digital video broadcast applications in the Chinese market. The design covers the 470MHz to 858MHz UHF band. The MAX2165 direct-conversion architecture eliminates the need for an IF-SAW filter. Programmable baseband channel-selection filters allow for operation with 7MHz and 8MHz channels. The fractional-N synthesizer reduces VCO lock time and minimizes close-in phase noise, thus eliminating the need for power-hungry, phase-noise reduction algorithms. The DMB-TH demodulator accepts I/Q inputs from the tuner and supplies a MPEG-2 transport stream to the USB chip. The USB chip enables interfacing with a laptop or desktop computer for viewing broadcast video and for lab analysis. 我们期待您的反馈！ 喜欢？不喜欢？有待改善？或为我们提供建议？请与我们联系 — 我们将根据您的意见或建议改善我们的工作。 网页评价或提供建议 自动更新 需要自动接收最新发布的应用笔记吗？请订阅EE-Mail™ (English only)。 更多信息   APP 4174: May 07, 2008 MAX2165 一次变频DVB-H调谐器   下载，PDF格式 (139kB)  AN4174, AN 4174, APP4174, Appnote4174, Appnote 4174