By using certain active switching components to directly modulate a narrowband antenna with a baseband pulse train, the information bandwidth of the antenna may be decoupled from its resonant bandpass limitations. Additionally, a novel design for a digitally-driven high frequency (HF) communication system may be realized by driving an electrically small antenna structure with a Class D switching amplifier that uses radio frequency (RF) bipolar junction transistors switched with a pulse-width modulated HF signal.6.5 Measured output of PWM section 73 6.6 Class A power amplifier circuit 76 6.7 Quiescent point differences between Class A and Class B power amplifiers 77 6.8 Class B power amplifier circuit 78 6.9 Crossover distortion effect of push-pull anbsp;...
|Title||:||Design and Development of Directly-modulated Antennas Using High-speed Switching Devices|
|Author||:||Steven David Keller|
|Publisher||:||ProQuest - 2008|