| dc.description.abstract | The thesis investigates the functional block circuits for RF receivers. The
designed circuits are implemented in TSMC 0.18-μm CMOS and 0.35-μm SiGe
BiCMOS technologies. The implemented circuits include a high linearity differential
low noise amplifier, a feed-forward sub-harmonic mixer, a Colpitts voltage controlled
oscillator for WiMax applications. A K-band differential low noise amplifier is also
studied for investigating the properties of differential circuits.
In WiMax low noise amplifier, linearity is improved by using feed-forward
correction technique. Since the using cascode compensation transconductor circuit,
the nonlinearity of the differential circuit can be cancelled at the differential outputs
and thus the LNA achieved high linearity without seriously degraded the NF. The
WiMax low noise amplifier achieves a power gain of 15.2 dB, a noise figure of 2.95
dB, input/output return losses of 23.3 dB, and 6.8 dB, respectively. The measured
1-dB gain compression point and the input third-order intercept point are -13 dBm
and +3 dBm, respectively, and total power consumption is 17.03 mW; A gm-boosting
technique was applied in K-band low noise amplifier. The transistor transconductor is
boosted by using transformer coupling. The K-band low noise amplifier achieves a
power gain of 8.2 dB, a noise figure of 7.8 dB, input/output return losses of 12.4 dB
and 10.2 dB. The 1-dB gain compression point and the input third-order intercept
point are -10 dBm and 0 dBm, respectively, and total power consumption is 49.93
mW. In the sub-harmonic mixer design, a differential feed-forward transconductor
stage was adopted to improve the third-order nonlinearity distortion and enhances the
conversion gain, simultaneously, which cancelled the unwanted third order
intermodulation products at the outputs. The obtained return loss of RF and IF ports
are both better than 10 dB. Low side local oscillator (LO) frequency is selected and
inter-mediate frequency (IF) is chosen as 10 MHz. the optimized LO driver is +2 dBm.
The conversion gain of mixer is 6.2 dB, with its RF 3-dB bandwidth from 2.5 GHz to
3.9 GHz. The IF 3-dB bandwidth is measured from 10 MHz to 150 MHz. The 1-dB
compression point and IIP3 are -8 dBm and +5 dBm, respectively. The port to port
isolations of RF-LO, LO-IF and RF-IF are better than -30 dB. In gm-boosting Colpitts
voltage controlled oscillator design, the power consumption can be reduced by
employing differential circuit inherent characteristic. The voltage controlled oscillator
yields a tuning range of 444 MHz, an output power of 1.54 ~ 2.92 dBm. The phase
noise at 100 KHz and 1 MHz offset frequencies achieves -101.4 dBc/Hz and -124.1
dBc/Hz, respectively. The power consumption of the VCO core dissipates only 2.46
mW. | en_US |