Title:

High-Frequency Power Amplitude Modulators with Class-E Tuned Amplifiers, Journal of Telecommunications and Information Technology, 2008, nr 4

Creator:

Mikołajewski, Mirosław ; Modzelewski, Juliusz

Subject and Keywords:

high-efficiency amplitude modulators ; non-ZVS operation ; sub-optimum operation ; PSPICE simulations ; optimum operation

Description:

A high-frequency power amplifier used in a drain amplitude modulator must have linear dependence of output HF voltage Vo versus its supply voltage VDD. This condition essential for obtaining low-level envelope distortions is met by a theoretical class-E amplifier with a linear shunt capacitance of the switch. In this paper the influence of non-linear output capacitance of the transistor in the class-E amplifier on its Vo(VDD) characteristic is analyzed using PSPICE simulations of the amplifiers operating at frequencies 0.5 MHz, 5 MHz and 7 MHz. These simulations have proven that distortions of theVo(VDD) characteristic caused by non-linear output capacitance of the transistor are only slight for all analyzed amplifiers, even for the 7 MHz amplifier without the external (linear) shunt capacitance. In contrast, the decrease of power efficiency of the class-E amplifier resulting from this effect can be significant even by 40%.

Publisher:

Instytut Łączności - Państwowy Instytut Badawczy, Warszawa

Date:

2008, nr 4

Resource Type:

artykuł

Format:

application/pdf

DOI:

10.26636/jtit.2008.4.903

ISSN:

1509-4553

eISSN:

1899-8852

Source:

Journal of Telecommunications and Information Technology

Language:

ang

Rights Management:

Biblioteka Naukowa Instytutu Łączności