| dc.description.abstract | This thesis describes several radio frequency circuit designs, which are adopted in WiMAX applications. They are implemented with TSMC 0.35?m SiGe BiCMOS process. The following sections will summarize the practical measured results which will be thoroughly presented in following chapters.
Chapter 2 introduces the designs of sub-circuits of radio-frequency transmitter, including up-conversion mixer, and variable-gain amplifier. These circuits are measured on FR4 print circuit boards. The up-conversion mixer achieves conversion loss of 9 dB, output P1dB of -11 dBm, output IP3 of -3 dBm, and superior to 29 dB isolation among all ports. The variable gain amplifier (VGA) has gain control range of 9.55 dB, and has gain of 8.75 dB, output power at the 1-dB compression point of -0.8 dBm, output third order intercept point of 16.8 dBm in high-gain mode, and gain of 4.1 dB, output power at the 1-dB compression point of 10 dBm, output third-order intercept point of 20 dBm in linear mode, gain of -0.8 dB, output power at 1-dB compression point of 1.2 dBm, output third-order intercept point of 12 dBm in low-gain mode.
Chapter 3 presents the designs of linear power amplifier, including a differential adaptive power amplifier, and a three-stage variable-gain power amplifier. These circuits are measured on FR4 print circuit boards. The former amplifier provides a 7.1 dB gain with input return loss better than 15 dB, output return loss is 13 dB and has output P1dB of 20.3 dBm, output IP3 of 28.1 dBm, the PAE@ P1dB of 23.6%. The latter amplifier provides a 25.2 dB gain with input return loss better than 8.9 dB, and has output P1dB of 20.6 dBm, output IP3 of 26.4, the PAE@ P1dB of 24.4%, and gain control range of 11.4 dB. | en_US |