High Linearity 1 5 2 5 Ghz Rf Mems And Varactor Diodes Based Tunable Filters For Wireless Applications

High Linearity 1.5-2.5 GHz RF-MEMS and Varactor Diodes Based Tunable Filters for Wireless Applications

The dissertation presents tunable banpass filters in the 1.5-2.5 GHz frequency range targeted for wireless applications. The tunable filters are designed for size miniaturization, good linearity and constant absolute bandwidth characteristics while maintaining low insertion loss. The improved linearity has been demonstrated using back-to-back varactor diodes and using RF MEMS devices. The constant absolute bandwidth characteristics was achieved using a novel corrugatedcoupled lines approach and also using a localized capacitive compensation concept. In the improved linearity varactor diode design, two miniaturized tunable filters with two zeros were developed at 1.4-2.0 GHz on. The filters were built using single and back-to-back varactor diodes and compared for linearity characteristics. The single diode filter has a 1-dB bandwidth of 5 " 0.5 % and an insertion loss of 2.5-1.8 dB. The back-to-back diode filter has a 1-dB bandwidth of 4.9 " 0.5 % and an insertion loss of 2.9-1.25 dB (resonator Q of 56-125). A detailed Volterra series analysis is done on the back-to-back diode including the effect of the bias network and diode mismatches. The measured IIP3 for the back-to-back diode tunable filter is 22-41 dBm depending on the bias voltage and is 13-15 dB better than the single diode design. The power handling capabilities of both designs is explored using large signal S21 measurements. To our knowledge, these planar tunable filters represent state-of-the-art insertion loss and linearity characteristics performance with varactor diodes as the tuning elements. In the corrugated coupled-lines design, miniaturized fixed and tunable microstrip bandpass filters were developed t 1.4-1.9 GHz. The novel approach uses microstrip corrugated coupled-lines concept to synthesize a coupling coefficient which maintains a nearly constant absolute bandwidth across the tuning range. In addition, a miniaturized 2-pole varactor tuned filter is demonstrated with a frequency coverage of 1.44-1.89 GHz and an insertion loss

High-Efficiency Load Modulation Power Amplifiers for Wireless Communications

This cutting-edge resource presents a complete and systematic overview of the practical design considerations of radio frequency (RF) high efficiency load modulation power amplifiers (PA) for modern wireless communications for 4G and beyond. It provides comprehensive insight into all aspects of load modulation PA design and optimization not only covering design approaches specifically for passive and active load modulation operation but also hybrid with dynamic supply modulation and digital signal processing algorithms required for performance enhancement. Passive load impedance tuner design, dynamic load modulation PA, active load modulation PA and Doherty PA design for efficiently enhancement are explained. Readers find practical guidance into load modulation PA design for bandwidth extension, including video bandwidth enhancement techniques, broadband dynamic load amplifiers, topology selection, design procedures, and network output. This book presents the evolution and integration of classical load modulation PA topologies in order to meet new challenges in the field.

Applied Science & Technology Index