向量調變式相移器設計

Abstract

相移器是在電子式多天線的通訊系統裡的一個重要電路,而電子式多天線通訊系統包括了相位陣列系統。可藉由相移器的功能，我們可以決定輸出波束的方向。在本論文中，學生提出了兩種架構的相移器。 第一個晶片是設計在2.25 GHz的4-bit相移器，使用TSMC 0.18-μm CMOS 製程。此電路主要由四相位產生器和可調增益放大器組成。由量測得知，此電路在中心頻率為2.25 GHz時，產生16個相位，且 root mean square (RMS) phase error 小於1度，root mean square (RMS) magnitude error小於 0.3 dB，核心電路增益為 -2.74 dB。當操作電壓是1.8 V時，核心電路的最大直流功率為10.28 mW。 第二個晶片是設計在0.75~2.67 GHz的5-bit相移器，使用TSMC 0.18-μm CMOS 製程。此電路主要由四相位產生器、放大器、衰減器組成。由量測得知，此電路在0.75~2.67 GHz時，皆可產生32個相位，且root mean square (RMS) phase error 小於3.5度(在2.67 GHz時最大)，root mean square (RMS) magnitude error小於 0.4 dB，核心電路增益為 3.6~-17.22 dB。當操作電壓是1.8 V時，核心電路的最大直流功率為6.39 mW。

The phase shifter is phase shifter is one of the most important circuit in multi-antenna communication system, such as phased array system. By the function of the phase shifter, we decide what direction of beam we want. In the thesis, two phase shifters are proposed. The first chip is 2.25 GHz 4-bit phase shifter in TSMC 0.18-μm CMOS technology. The phase shifter is composed with quadrature phase generator and variable gain amplifier. From the measurement results, when the phase shifter is at the center frequency, it generates 16 states of phase. The root mean square (RMS) phase error and the root mean square (RMS) magnitude error are lower than 1 degree, and 0.3 dB, respectively. The gain of phase shifter is -2.74 dB. The DC power consumption of core circuit is 10.28 mW from 1.8 V supply. The second chip is 0.75~2.67 GHz 5-bit phase shifter in TSMC 0.18-μm CMOS technology. The phase shifter is composed with quadrature phase generator, amplifier, and attenuator. From the measurement results, when operating frequency of phase shifter is 0.75~2.67 GHz, it generates 32 states of phase. The root mean square (RMS) phase error and the root mean square (RMS) magnitude error are lower than 3.5 degree, and 0.4 dB, respectively. The gain of phase shifter is 3.6~-17.22 dB. The DC power consumption of core circuit is 6.39 mW from 1.8 V supply.