The impact of coupling on the reflections of cavity resonators

2014 IEEE International Black Sea Conference on Communications and Networking (BlackSeaCom)

et al. 2014

Self Cite

To cope with the increasing demand for bandwidth in wireless communications coding schemes with high crest factors are employed. As a result the power amplifier (PA) is operated far below maximum output power for most of the time, leading to low average efficiency in traditional designs. Therefore PA concepts providing efficiency enhancement in back off are key for efficient transmitters. Baseband PWM operated PAs in combination with direct filter connection are possible candidates. Due to the constant current of the used filters special PA structures are required. The proposed source modulated amplifier offers these properties. Its general operational principle is presented and an implementation study in a GaN MMIC process was carried out. The designed PA operates at 2.65 GHz delivering a maximum output power of 3W. To get optimum performance of the direct filter connection a codesign of the PA and the cavity filter included in the output matching network was performed, resulting in a compact solution.

Section: Discrete Source Modulated Amplifiermentioning

confidence: 99%

A source modulated amplifier in GaN designed for baseband PWM and direct filter connection

2014 IEEE International Black Sea Conference on Communications and Networking (BlackSeaCom)

et al. 2014

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“…To achieve the required matching network for best performance of the direct filter connection a codesign of the cavity bandpass filter and the PCB output matching was done. For the BPF measured data of the cavity filter presented in [9] was used, while for the PCB a Rogers 4350B substrate was considered. The resulting arrangement is depicted in Fig.…”

Section: Common Drain Parallel Amplifiermentioning

confidence: 99%

A common drain parallel amplifier in GaN using baseband PWM and direct filter connection for efficiency enhancement

2014 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC)

et al. 2014

Self Cite

To cope with the increasing demand for bandwidth in wireless communications coding schemes with high crest factors are employed. As a result the power amplifier (PA) is operated far below maximum output power for most of the time leading to low average efficiency in traditional designs. Therefore PA concepts providing efficiency enhancement in back off are key for efficient transmitters. Baseband PWM operated PAs in combination with direct filter connection are possible candidates. Due to the constant current of the used filters special PA structures are required. The proposed parallel common drain amplifier offers this properties. Its general operational principle is explained and an implementation study in a GaN MMIC process is presented. The designed PA operates at 2.65 GHz delivering a maximum output power of 3W. To get optimum performance of the direct filter connection a codesign of the PA and the cavity filter included in the output matching network was done, resulting in a compact solution.

“…The BPF has its center frequency around 2.648 GHz determining the design frequency. Measured S ‐Parameters from the filter presented in were used for simulation.…”

Section: Design Examplementioning

confidence: 99%

Equivalent load impedance of pulse width modulation excited band pass filters

Int J RF and Microwave Comp Aid Eng

et al. 2014

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Many efficiency enhancement concepts for power amplifiers (PAs) rely on pulse width modulation in combination with direct filter connection. Direct connection of bandpass filters results in load modulation for the PA. Therefore, the resulting equivalent impedances, respectively, load trajectories, are important for efficient operation. This article presents analytical equations to calculate these equivalent load impedances. The equations are parameterized with two impedance values making them independent of the filter structure. Based on the presented equations a PA design properly taking the load modulation into account can be done. This is shown based on a design example of a biphase energy recovery transmitter, verifying the general validity of the equations. V C 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:164-172, 2015.