| dc.description.abstract | This thesis describes several radio frequency circuit designs for WiMAX applications. They are implemented in TSMC 0.35 ?m SiGe BiCMOS and 0.18 ?m CMOS technologies, respectively. The implemented circuits include one power amplifier (PA) using the capacitance compensation and harmonic control technique, two PAs using transformer coupling technique, three voltage controlled oscillators (VCOs) using gm-boosting, transformer feedback, complemently cross couple techniques and one frequency divider. These PAs and VCOs operating at 2.6 GHz are realized for the two-step transmitter architecture in mobile WiMAX system.
The measured results are summaried as below：PA with capacitance compensation and harmonic control technique one, achieves a power gain of 13.2 dB with input return loss 9.04 dB, output return loss of 5.4 dB, 1-dB gain compression point (P1dB) of 20.2 dBm, the output third-order intercept point (OIP3) of 28.2dBm, power added efficiency (PAE) at P1dB of 24.4 %. PA with transformer coupling technique one achieves a power gain of 8.2 dB with input return loss of 8.63 dB, output return loss of 7.56 dB, P1dB of 23.3 dBm, the output third-order intercept point (OIP3) of 27.5dBm, PAE at P1dB of 17.04 %. PA with transformer coupling technique two achieves a power gain of 18.35 dB with input return loss better than 10 dB, output return loss of 3.97 dB, P1dB of 24.2 dBm, the output third-order intercept point of 27.8dBm, PAE at P1dB of 15.9 %. Differential Colpitts VCO with Gm-boosting reduces the power consumption which yields a tuning range of 360 MHz, an output power of 0.92 ~ 2.11 dBm. The phase noise at 100 KHz and 1 MHz offset frequencies achieves -90.9 dBc/Hz and -118.2 dBc/Hz, respectively. The power consumption of the VCO core dissipates only 3.156 mW and FOM is -187.8 dBc/Hz.Transformer feedback VCO yields a tuning range of 320 MHz, an output power of -1.82~0.73 dBm. The phase noise at 100 KHz and 1 MHz offset frequencies is -94.2 dBc/Hz and -120.1 dBc/Hz, respectively. The power consumption of the VCO core dissipates only 3.22 mW with FOM of -182.97 dBc/Hz. Complemently cross-coupled VCO and frequency divider yields a tuning range of 360 MHz, an output power of -3.9 ~ -2.8 dBm. The phase noise at 100 KHz and 1 MHz offset frequencies is -92.6 dBc/Hz and -117.4 dBc/Hz, respectively. The power consumption of the VCO core dissipates only 7.2 mW with FOM of -183.3 dBc/Hz. The total loacking range of frequency divider is from 0.37 ~ 3.7 GHz. | en_US |