寬頻一進二出放大器設計

Abstract

由於積體電路的元件設計和系統整合皆已經發展相當成熟，接收器陣列是未來主流之一。如果把一組接收器系統比擬為一雙眼睛，那麼接收器陣列就像是蒼蠅的複眼，不但可以接收到更微弱的訊號，還可以增加接收訊號的廣度;在一個超寬頻的接收器系統當中，由於接收的訊號太寬，必頇先經由功率分配器輸出多路訊號之後再做切割與降頻，以提供較低頻且窄頻的訊號給後級的類比數位轉換器處理。然而，傳統的功率分配器大多使用由被動式元件組成的多階項功率分配器來達到寬頻的效果（例：威爾金森功率分配器）。此種功率分配器雖然不消耗功率，卻會佔用相當可觀的面積，無法順利做成接收器陣列。此外，被動式功率分配器在寬頻的應用之下在隔絕度上有很大的限制，如果使用在對於輸出訊號獨立性要求特別高的系統當中，通常需要外接其他元件才能夠達到足夠的隔絕度，實用性上不是很高。為了更進一步的改善傳統被動式功率分配器在面積消耗和寬頻之下隔絕度的限制，在此提出結合主動式元件的功率分配兼放大器。利用主動式元件本身具有良好的隔絕度，輸出獨立性極高的兩路訊號，更能夠以積體電路來取代原本需要極大面積的被動式功率分配器。

Since the developments of the IC components design and system integration have been quite mature, receiver array is one of mainstream in the future. If we compare a receiver system to eyes, the receiver array would be the compound eyes of the flies which can catch weaker signals and possess the more extensive range. However, it requires power dividers to split out multiple signals; Multi-section Wilkinson power divider is one of the most common power dividers which can reach wideband achievement. Although such passive power divider does not consume any DC power, it requires considerable area. Besides, Wilkinson power divider has a severe limit to isolation in the wideband application. Inevitably we have to add other device to achieve enough isolation while a system demanding of particularly independence between two output signals. This solution is not that efficient. In order to overcome the area consumption and isolation limit problems, we report the active splitter amplifiers integrating active devices. Active power dividers can provide two highly independent signals by employing active device which has good isolation in itself, and reduce area to an IC size.