Design and Fabrication of a New UHF Multi-Channel Frequency Push-Pull Power Amplifier for Digital Video Broadcasting-Terrestrial Network using Multi-objective Pareto-based Genetic Algorithms Optimization
Digital Video Broadcasting-Terrestrial transmitters (DVB-T/T2) sets are designed for reception of TV broadcasts in VHF (174-230 MHz) and UHF (470-790 MHz) bands. They provide an effective solution for the reception of DVB-T/T2 transmitters broadcasting with various combinations of polarizations in the VHF and UHF bands. In the present paper, for the purpose of Digital Video Broadcasting-Terrestrial (DVB-T/T2) transmitters and military wireless systems, an optimized out-phasing push-pull power amplifier based on Pareto genetic algorithm optimization is designed for ultra-high frequency (UHF) applications using Laterally diffused metal oxide semiconductor (LDMOS) transistor. In the new DVB-T/T2 Multi Frequency Network (MFN) transmitters, radio frequency power (RF) amplifier products, the linearity, efficiency, and broadband bandwidth all needed to be improved. Herein, three LDMOS-RF transistors are utilized in two stages. The multi-objective pareto genetic algorithm (MOPGA) is used to optimize the input and output matching networks, and insertion loss of matching network.In DVB-T/T2 transmitters the power output of modulator is low (1Mw). For this purposed the broadband out-phasing power amplifier is designed with optimal gain (EX: 40dB) in UHF bands. In the first step, the Agilent Design System (ADS) simulations are used. A gain >42 dB was achieved with an optimized matching network. The intermodulation distortion (IMD) is calculated between -29 and -52.2 dBc. The power-added efficiency (PAE) of 32-66% is obtained in the frequency range of 400-900 MHz in this study. Subsequently, an amplifier printed circuit board is fabricated.