雷達微波元件開發

Abstract

本論文呈現一些震盪器、放大器、倍頻器和混頻器的電路，茲以提供防撞雷達使用。在第一部份，我們建構出各種震盪器並比較其效能。其中大多數的震盪器都滿足防撞雷達的規格要求。在接下來的部分，具增益的倍頻器與放大器也初步地發展完成。最後一部份，則詳細介紹四種混頻器的建構與原理。此四種混頻器都是架構在介板高度20 mil 之Rogers RO4003 的介板上來降低板耗成本。第一種的升頻器是利用岔路環耦合器所製成的混頻器。其轉頻耗損在12.45GHz頻率平均約為6dB以下。第二種是24GHz並聯反相二極體次諧波降頻混頻器。但由於此降頻混頻器成果並不符合防撞雷達性能要求，因此我們另外提出低成本的單端電阻性1/2和1/4次諧波混頻器。1/2電阻和1/4電阻次諧波混頻器其轉頻耗損在24GHz頻率分別是約10dB及13dB。此種混頻器完全不損耗直流功率，並具有低的交互調變特性。而其功率耐載度也較一般主動次諧波混頻器好。

This thesis presents some oscillator, amplifier, doubler and mixer circuits that are developed for CW and FMCW. In the first part, we constructed several oscillators. Of course most of them attained the mission need of FMCW and CW. In the following part, the 12GHz to 24GHz doubler with conversion gain, 12.45GHz amplifier, and 24GHz amplifier with 14dB transmission gain were also constructed. In the last part, we fabricate four types of mixer. All these mixers are fabricated with 20mil Rogers RO4003 substrate to minimize the cost. First type is the microstrip hybrid rat-race ring mixer for Ku-band upconverter. The conversion loss of this mixer is averagely blow 6 dB at RF frequency of 12.45GHz. Second type is 24GHz APDP subharmonic mixer. Due to the low performance of the APDP 1/2-subharmonic mixer, we present low-cost resistive FET 1/2- and 1/4-subharmonic mixers using packaged HEMT (NE3210S01). The working frequency is also at 24GHz. The measured conversion loss is approximate 10dB for 1/2- and 13dB for 1/4-subharmonic mixer. The mixer is no bias (0 volt) for both drain and gate. The measured 1-dB compression power is 6.5dBm for 1/2- and 9dBm for 1/4-subharmonic mixer. The power handling capability is better than that of an active subharmonic mixer.