應用於第五代行動通訊之28 GHz相移器與升頻混頻器研究

Abstract

本論文主要研究領域為相移器與升頻混頻器。近年來高速通訊蓬勃發展，從過去的語音傳輸，發展至現今影片與龐大資料的傳輸需要更高無線通訊的頻段，以滿足大量的資料傳輸需求，第五代行動通訊為近日研究主流，28 GHz為可能之發展頻段，故本文所設計之電路將以此頻段作為研究重點。 本論文前半段介紹各類相移器，並且針對開關式相移器進行分析，接著說明兩顆五位元開關式相移器之設計與實現。第一顆相移器，其中四個位元採用T橋式相移器，採用高通與低通電路的組合。經過重新設計後的版本，操作頻率為26 GHz至31 GHz時相位誤差均方根小於4.39°以及振幅誤差均方根值小於0.79 dB，在中心頻率28 GHz時，擁有2.72°相位誤差均方根值以及0.61 dB振幅誤差均方根值。 第二顆晶片也是五位元開關式相移器。為了達到增加頻寬的目的，相較於第一版本的90°相移器採用T橋式架構，此電路採用反射式相移器架構，其餘四個位元和第一顆相移器架構相同。操作頻率為26 GHz至31 GHz時相位誤差均方根小於4.06°以及振幅誤差均方根值小於0.88 dB，在中心頻率28 GHz時，擁有2.56°相位誤差均方根值以及0.83 dB的振幅誤差均方根值。 本論文後半段介紹第三個電路，也是最後一顆晶片，升頻混頻器，此電路採用被動式架構以及次諧波混頻架構，以達到高頻寬、低功耗以及高隔離度。中心頻率28 GHz，且LO驅動功率為2.5 dBm時，在24 GHz至38 GHz擁有 dB的轉換增益以及小於70 dB的2LO to RF的隔離度，在LO驅動功率為9 dBm，RF頻率為28 GHz下擁有-21.2 dBm的轉換增益。The main research field of this thesis is based on phase shifter and up-converter mixer. From telecommunication to big data, higher frequency spectrum is needed for the large amount of data. Therefore in order to satisfy tremendous data transmission these days, fifth generation wireless communication system has been proposed and populated. We focus our research on 28 GHz, the potential spectrum in 5G system, which is used among three circuits throughout this thesis. In the first half of this thesis, we introduce different types of phase shifter, and analyze switch type phase shifter used in this thesis, then express the design and implementation on two circuits, phase shifters. The first circuit is five bits switch type phase shifter, four in five bits used bridged T-type and used high-pass and low-pass to fulfill the circuit. After modifying the circuit, frequency operated from 26 GHz to 31 GHz has lower than 4.39° RMS phase error and 0.79 dB RMS amplitude error. The central frequency 28 GHz, has 2.72° RMS phase error and 0.61 dB RMS amplitude error. The second circuit is also a five bits switch type phase shifter. To increase bandwidth, reflection type architecture is substituted for bridged T-type in 90° phase shifter and the other four bits have the same architecture as the first chip. Frequency operated from 26 GHz to 31 GHz was observed to have lower than 4.06° RMS phase error and 0.88 dB RMS amplitude error. The central frequency 28 GHz, has 2.56° RMS phase error and 0.83 dB RMS amplitude error. In second half of this thesis, the third and also the final chip circuit is introduced. Passive and sub-harmonic technique are used in up-converter mixer to achieve broad bandwidth, low dc consumption and high isolation. The conversion gain is dB at LO drive power is 2.5 dBm and lower than 70 dB 2LO to RF isolation when the frequency is ranged from 24 GHz to 38 GHz. When LO power is 9 dBm, RF frequency is 28 GHz is -21.2 dBm.