Research And Design Of CMOS Multi-band RF Power Amplifier

The application of 3G communication standard allows development of new wireless devices that combine voice, internet, and multimedia services in order to satisfy the increasing demand for data/internet services. This evolution will bring new requirements on the RF parts of the transmitters which would have the multi-band work performance.In this paper, the RF power amplifier's essential requirements are expatiate, including performance parameter, matching network, stability and linearization, then, basic design principle of each classes power amplifier including linear and nonlinear power amplifier's basic structure were introduced in this paper, and the comparison of performance of each classes power amplifier, the input matching network and the output matching network of the multi-band power amplifier were investigate, in the design of input matching network the passive component capacity inductance parallel structure was used, this made it perform as a capacity under the high frequency or a inductance under the low frequency, thus it matched to the source impedance 50Ωboth in two different frequency bands. Simultaneously, the two kinds of output matching network and the input and output matching network detailed analysis were presented. Considering the chip area, one kind of output matching network has been chosen, Finally a multi-band two-stage PA was proposed.The circuit was designed in SMIC 0.18μm RF CMOS technology and stimulated by Cadence Specter RF. The simulation results indicated that the multi-band PA has the good linearity and the stability, the power gain at 850M/900MHz band was the 22.8dB with the maximum 15.1% PAE, and at the 1.8G/1.9GHz band was the 15.3dB with maximum 13.6% PAE. The layout of the multi-band PA and the biasing circuit which provides two different dc voltages was completed by using the layout tool of Cadence Virtuoso Layout Editor. The die area of the final Multi-band PA is 1.49mm×1.02mm.The post-simulation was done.