應用於Ka 頻段僅使用功率量測之單晶片相對相位及振幅偵測系統

Abstract

本論文主要研究毫米波頻段之相對訊號大小及相位的偵測電路，操作頻率為第五代通訊系統所適用之Ka 頻段，可應用於相位陣列單位之間，檢測大小以及相位的正確性。首先，將介紹傳統的相移器、訊號偵測系統的架構以及文獻，接著，介紹其中電路的原理、應用目的，最後則介紹本論文所提出的兩個向量偵測系統。 本論文提出的第一個電路為透過相移器、耦合器與功率偵測器組合而成的偵測系統。使用台積電 180 nm CMOS 製程，晶片面積為0.82 μm × 0.75 μm。利用兩路輸入，一路搭載相移器，透過開關控制相移大小，另一路則直接輸入訊號。兩路訊號經180°耦合器可產生二路干涉的訊號，經由功率偵測器可轉為直流電壓輸出。功率偵測器於28 GHz 下及線性誤差為1 dB以下時，可偵測-4 dBm ~ 9 dBm的訊號，靜態直流功號為 0.84 mW。相移器可產生160°的不連續相位差，均方根相位誤差為5.4°，均方根振幅誤差則為1.5 dB。在不同相位下的功率經計算後可得出輸入兩訊號間的相對大小及相位。 本論文提出的第二個電路亦為相同架構的向量偵測系統，使用台積電 180 nm CMOS 製程，晶片面積為0.81 μm × 0.76 μm。改進了相移器的設計，總共可產生164°的不連續相位差，均方根相位誤差為4.0°，均方根振幅誤差則為1.8 dB。 第一顆整體向量偵測器測出的相位差與實際誤差為15°，振幅誤差為9%。而第二顆相差8°，振幅部分則與實際相差20%。

This thesis studies relative power and phase detection system, which operates in Ka-band for 5G communication and is proposed to measure the phase and amplitude ratio between phase-array elements. First, this thesis reviews literatures related to phase shifter and power detector circuits as well as introduces their structures, theory, and application. Second, the thesis introduces two relative power and phase detectors which combine the phase shifter, coupler and the power detector. The first chip is a Ka-band vector detector system implemented by TSMC 180 nm CMOS technology and the chip size is 0.82 mm × 0.75mm. The measured dynamic range of power detector is from -4dBm to 9dBm at 28 GHz, under 1 dB log-error. The phase shifter had 5.4° RMS phase error and RMS amplitude error is 1.5dB. The second chip of Ka-band phase detector system is also implemented by TSMC 180 nm CMOS technology and the chip size is 0.81 mm × 0.76mm.This phase shifter is redesigned to give better phase uniformity. The phase shifter had 5.4° RMS phase error and RMS amplitude error is 1.5dB. Compared with actual amplitude and phase, the measured results of first chip have 15° phase error and 9% amplitude error. The results of second chip have 8° phase error and 20 % amplitude error.