Research on K-band Active Antenna Integrated with Adaptive-bias Power Amplifier Using CMOS and IPD Process

• Main Authors: Ying-Chia Chen, 陳瑩嘉
• Other Authors: Kun-You Lin
• Format: Others
• Language: en_US
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/11048735395350296035

碩士 === 國立臺灣大學 === 電信工程學研究所 === 104 === The demand for more compact, smaller size and longer using time transmitter in wireless communication system has increased according to the rapidly development of communication technique and high date-rate transmission. The power amplifiers (PA), which requires high gain, high output power and high efficiency, plays a necessary role in the communication system. Due to that power amplifier consumes the most dc power in the transmitter, the optimization of the efficiency becomes a key issue. Several new structures of power amplifier are proposed recently in order to achieve good linearity and efficiency. In this thesis, two circuits are designed and realized. The first is a differential power amplifier using adaptive-bias technique, and the second one is an active antenna integrated with adaptive-bias power amplifier. The former is realized by 0.18-μm CMOS technology while the latter is implemented on CMOS and IPD technology. The operation frequency is 24 GHz. The K-band differential power amplifier which adapts an adaptive-bias technique to increase the efficiency of the power amplifier is described in the first part. This power amplifier is fabricated in 0.18-µm CMOS technology. According to the measurement, the designed PA consumes 104 mW at quiescent state. The power-added-efficiency at OP1dB is 3.9% while maintaining 6.5-dB small-signal gain, 10-dBm OP1dB and 10.5-dBm Psat. In the second part, a K-band active antenna integrated with CMOS adaptive-bias PA is proposed to improve the efficiency of the PA. This circuit includes a CMOS adaptive-bias PA and a dipole antenna; the power amplifier is realized by 0.18-µm CMOS technology and the antenna is implemented on IPD technology. The active antenna integrated with power amplifier adapts the adaptive-bias technique to improve the power amplifier efficiency under back-off operation. Besides, the input impedance of the antenna is designed to be the optimal load of the PA in order to eliminate the loss caused by output matching network, and the efficiency is improved as a consequence. The measurement results of PA shows that the peak PAE is 26.7% and PAE is 24.1% at 19-dBm OP1dB at 24GHz. The measurement results show that the efficiency of the PA is significantly improved.