L-band Broadband Miniaturized Power Amplifier Modeling And Design

Nowadays, low distortion and high efficiency are contradicting requirements for an RF power amplifier (PA). In many instances, designers must make a tradeoff between one of these parameters to achieve better performance on the other. Power amplifier line ups in lateral diffused metal-oxide-semiconductor (LDMOS) technologies have dominated almost a decade in cellular base stations, mainly in discrete device configuration. Silicon LDMOS technology has a strong position in base station applications due to its benefits, which are: 1) improved efficiency; 2) linearity; 3) peak-power capability; and 4) cost-per-watt performance.In the thesis, a 7W mini wideband PA working at the L band (0.9GHz to 1.3GHz) has been researched based on the transistor model and mini circuit design work.Class-A&AB PAs are often used in such systems where high spectral linearity is needed. This operation mode gives a good linearity for a reasonable value of efficiency. These types of PA architectures could be directly inserted into a telecommunication system working from 0.9GHz to 1.3GHz. They could also be served as a driver amplifier because of its good dynamic range and linearity and could be associated with another one to build up a wideband high power amplifier.In this thesis, the PA model is CSDA47835859345 and based on the Angelov I-V model and small signal S-parameter modeling work, we obtain the more accurate transistor model data, and we design and simulate the optimized circuit by Agilent ADS2008 software. After researching of the transistor model, coupled with simulation software, actual circuit debugging, broadband and compact design optimization, we realize to design a L-band mini PA.One single-stage class-A power amplifier (PA) with gain of 14dB working from 0.9 to 1.3 GHz have been developed based on its model building work. The PA uses one LDMOS transistor as an active element in order to generate high efficiency and linearity with high output power. The wide band PA achieved an efficiency of 38.3% with 38.82dBm of output power and -24dBc IMD3 figure. To our knowledge, these results represent good wideband characteristic and the high efficiency and output power for a class-A PA based on a single-stage LDMOS transistor working at this frequency. This PA design is the best tradeoff among the compact design, broadband, efficiency and linearity figure.