AMiBA接收機倍頻與中頻模組之 電源電路與控制電路研製

Abstract

本論文主要敘述AMiBA無線天文望遠鏡接收機之倍頻與中頻模組，以組裝MMIC方式及氧化鋁製程，並配合量產考量將其尺寸微小化設計，以及配合MMIC設計高頻電路、直流電源電路及控制電路。高頻電路包含被動電路設計、主動電路及MMIC組裝，直流電源電路是針對電源與控制電壓電路做設計，目的是操作時經由電腦控制輸入電壓，並分別研製與測試電源電路及控制電路。其中倍頻模組包含倍頻器、90o耦合器、單刀雙閘微波開關、壓控衰減器以及42GHz後級輸出放大器，使21GHz本地振盪器信號，經過倍頻模組，將信號從21GHz倍頻到42GHz，然後輸入接收機之次諧波混波器。中頻模組則包含行波放大器、步階阻抗低通濾波器及壓控衰減器，模組內有兩條極化路徑，都內含三級2-18 GHz寬頻放大器及三級低通濾波器，經由同軸線輸出到相關器進行訊號處理。希望本論文能提供AMiBA接收機倍頻及中頻模組之量產考量，以其微小化及低成本的優點，替換現有之模組。

In purpose of using MMICs and Al2O3 process to miniaturize the dimensions of multiplier frequency module and intermediate frequency module for the application in the AMiBA receiver, this thesis describes the design of the radio frequency circuits and the DC circuits. The radio frequency circuits include the passive circuits using Al2O3 process and the active circuits using MMICs. The DC circuits are designed to be controlled by a computer to provide the RF bias and control signals. The multiplier module mainly consists of doubler, 90o coupler, 90 o phase shifter, voltage-controlled attenuator and power amplifier. It receives the 21GHz local source signal and doubles to 42GHz to the sub-harmonic mixer. The intermediate frequency module mainly consists of traveling wave amplifier, step-impedance low pass filter and voltage-controlled attenuator. It includes two paths for two orthogonal polarized signals. The output signals of the intermediate frequency module are then connected to the following correlators through coaxial cables. The development of the DC circuits and control circuits in this thesis can provide a reference for the future expansion of AMiBA receiver on the considerations of low cost and mass production.