The ever-increasing demand for low-cost portable devices has motivated the research on high frequency CMOS communication integrated circuits. We designed and implemented a transmitter chain that will be part of a single-chip 24-GHz CMOS radio for sensor network applications. The radio includes a RF transceiver, an on-chip antenna, a baseband processor, a sensor, and eventually a battery. The integration of an antenna on the same chip greatly simplifies the package, lowers the device cost to less than {dollar}1, and makes the radio easy to use.; The transmitter includes a minimum shift key (MSK) modulator, IF amplifiers, an up-conversion mixer, drivers and a power amplifier. A discrete approximation of the MSK using phase interpolation simplifies the modulator design and lowers the power consumption. A mode locking technique using positive feedback is also proposed to improve the power added efficiency (PAE) of power amplifier to 23.5%. The transmitter chain implemented in the UMC 0.13-mum CMOS provides 8-dBm output power to a 50-O load and 7.7% rms error vector magnitude (EVM) while dissipating 100 mW. The signal transmitted by the chain with an on-chip antenna was picked up 5 meters away using an on-chip antenna, and 95 meters away using a horn antenna with 20-dBi gain. These demonstrations prove that short-range wireless communications using a single-chip radio with an on-chip antenna are possible.; Frequency sources for future millimeter-wave applications are also demonstrated. The transistors, varactors, and inductors are optimized to reduce the parasitic loss and capacitances. The components are used to realize wide tuning range 60-GHz voltage-controlled oscillators (VCO's) in UMC 0.13-mum CMOS and VCO's around 140 GHz in UMC 90-nm CMOS processes. We also used push-push architecture obtain an operation frequency of 192 GHz in 0.13-mum CMOS. This is the highest operating frequency for any silicon-based circuit. Our study also showed that the lumped element approach can be used even for circuits operating well above 100 GHz. A PLL tunable from 45.9 to 50.5 GHz was also implemented in 0.13-mum CMOS process. The power consumption was reduced to 57 mW by using an LC-oscillator based injection locked frequency divider (ILFD) while the operating frequency range is increased by tracking the VCO and ILFD self oscillation frequencies. These results indicate the feasibility of implementing millimeter-wave applications using low-cost CMOS technology. With more advanced CMOS processes, it should be possible to extend the frequency to sub-millimeter or THz range.
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