Ka頻段中繼雙訊模組設計

Abstract

本論文研製之Ka頻段中繼雙訊模組設計，可應用於智慧型傳輸系統(ITS, Intelligent Transport System)中，扮演車置單元(OBU, On-board Unit)或是車道單元(RSU, Road-side Unit)的角色。其不僅是一個微波頻段(中頻信號)與微米波頻段(射頻信號)昇、降頻的介面，也允許提供全雙工的傳輸通道給予其工作頻段接近2.4GHz的單元A與B(ELEMENT A and B)。 此模組包括三個子模組︰中頻子模組、本地頻率子模組與射頻子模組。中頻子模組的功能是將單元A的工作頻段昇頻至3.4GHz，並將其與單元B信號合成為中頻信號。本地頻率子模組含有一個壓控震盪器與鎖相迴路電路，穩定地提供不僅一組5.85GHz的本地信號源給中頻子模組，且利用三倍頻器、功率分配器與放大器產生額外兩組17.55Ghz本地信號源給發射與接收之射頻子模組。射頻子模組利用內部的次諧波混頻器電路，將中頻信號昇頻至射頻頻段並藉由天線發射，或是將接收到的射頻信號降頻至中頻頻段給中頻子模組。 最後量測的結果是：車置單元與車道單元之間的傳送距離為10公尺於資料傳輸率為每秒950千位元時。

The thesis is a design of Ka band HUB diplexer module which would be applied to the intelligent transport system to play the role of on-board or road-side unit. It is not only the interface between the microwave (IF signal) and millimeter-wave (RF signal) to up- or down-convert signals, but also allowed to provide full-duplex communication channels for both ELEMENT A and B of operation frequency near 2.4 GHz. This designed module is included in three sub-modules: IF sub-module, local frequency sub-module and RF sub-module. The function of IF sub-module is converting the operation frequency of ELEMENT A up to 3.4 GHz, and combining itself with the signal of ELEMENT B as the IF signal. There are one voltage controlled oscillator and a phase-locked loop circuitry in the local frequency sub-module to stably give not only IF sub-module a local frequency source of 5.85 GHz, but also additional two sets of 17.55 GHz source for the transmitting and receiving RF sub-module respectively by circuitries of frequency tripler, power divider and amplifiers. The RF sub-module is applying the inner sub-harmonic mixer to converting the IF signal up to RF pass-band and then transmitting it via the antenna, or to converting the received RF signal down to IF pass band for the IF sub-module. The final measured result: the communication distance between the on-board and road-side unit is 10 meter at the data rate of 950K bytes per second.