數位式降頻器機構設計與熱分析

Abstract

降頻器是一個衛星天線系統的無線電接收器，也是接收衛星電視不可欠缺之設備。隨著通訊技術的發展及數位化時代的來臨，衛星電視系統必須提供更多元化及高畫質的服務，才能滿足使用者的需求。 本研究目的為探討數位式降頻器之熱傳遞及分佈情形，以及使用不同的機械材料，來驗證及改善產品過熱的問題。 本研究利用CFdesign熱模擬分析軟體進行降頻器的溫度分佈計算，並在恆溫恆濕試驗機中做產品的溫度實測，最後再將模擬與實驗量測的溫度結果相互比較以完成分析。 研究結果顯示，使用熱傳導係數K值高的材料，對於熱的傳遞是有幫助的，以及利用CFdesign軟體模擬降頻器的溫度分佈與在恆溫恆濕試驗機中所量測的溫度差異約在4°C以內，兩者相差不大。 綜合模擬和實驗量測的結果，證明產品在研發設計階段，就可使用CFdesign軟體模擬產品的溫度分佈情形，可節省產品開模後修改的頻率及費用，減少產品開發的時程。

Downconverters are radio receivers in satellite antenna systems and are indispensable components for satellite television reception. With the advance of communication technologies and the advent of digital era, satellite television systems must provide diversified services and high-quality images for the increasing user demands. This study investigated heat transfer and distribution in digital downconverters. Various mechanical materials were used to verify and improve the overheating problems of downconverter products. CFdesign thermal simulation software was used to calculate the temperature distribution in the downconverter. Additionally, product temperatures were physically measured using a thermostatic-humidistat testing machine. Finally, the simulated and experimentally measured temperatures were compared to complete the analysis. The results showed that using high-k (thermal conductivity) materials facilitated thermal conduction. Moreover, the temperature distribution from the CFdesign simulation and that from thermostatic-humidistat experiment yielded similar results, with errors of less than 4 °C. In summary, the CFdesign software was verified to be a feasible design aid for simulating temperature distributions during product development, thereby reducing the modifications and costs involved after molding a product and streamlining the development process.