Development&Application Of Tracking Filter Based On Closed-Form Modeling Of SMD

As the popularization of the digital cable TV in China, it is in dire need of designing the tramsission and receiving digital TV system in self-determination. The Tuner is the very important part in the digital TV receiver system. The key function of the tuner is receiving and sending the RF TV signal to modules behind in the system for demodulation and decode.SER1001T03 was the single conversion tuner chip designed by the National ASIC System Engineering Research Center in Southeast University. The chip integrates Mixer, IF amplifer, Oscillator, IF AGC and programmable PLL. The objective of the research paper was to make use of the tuner chip and design tracking filter in the front-end of digital TV receiver system and receive the digital TV programs which are based on the Nanjing Broadcast System.At first, kinds of the tuner receiver system are descriped and the single conversion tuner based on the DVB_C standards is the final choice. Then, Closed-Form modeling of RF SMD inductors and capacitances is analyzed and abstracted. The designs of the first stage of the tracking filter, AGC and the second stage of the tracking filter are described detailly in the next part, considering impedance matching, image rejection the offset of the AGC and the circuit tansformation from single-end port to banlanced ports. In the end, all the modules are designed into measurement PCB. After mounting all the necessary devices, the results of measurements are given at the end of the article. The results show that the tracking filter can cover all the frequencies used by Nanjing Broadcast System, and the typical value of Image Rejection is 60dB. The TV displays the video clearly using the tuner system including the tracking filter designed in this paper.The tuner system including the tracking filter described in the paper is one of the applications of the SER1001T03 and the article accumulates the design experience for the full band receiving. The result seems to suggest industrialization of the tuner chip.