Alexander MacMullen

Learn More
A theory is presented which offers an explanation for many of the causes of ion-induced instabilities of the phase and amplitude of the RF output of a solenoid-focused 10-kW continuous-wave coupled cavity traveling-wave tube (TWT). This theory is based on the effects of ions in the electron gun. Some of these ions enter the gun from the interaction region(More)
A programmable ultra-low noise X-band exciter has been developed using commercial off-the-shelf components. Its phase noise is more than 10 dB below the best available microwave synthesizers. It covers a 7% frequency band with 0.1-Hz resolution. The X-band output at +23 dBm is a combination of signals from an X-band sapphire-loaded cavity oscillator (SLCO),(More)
Extremely low noise levels are frequently required in radar and communication systems that utilize microwave tubes. A noise waveform frequently found in continuous-wave (CW) linear-beam microwave tubes is a relaxation-type oscillation that has a period typically on the order of several milliseconds. This paper provides an extensive experimental(More)
To improve the repeatability and correlation of signal-to-noise ratio measurements of microwave power tubes between test sites, and between test sets at the same test site, a self-calibrating measurement technique has been developed. This technique results in an accuracy of better than 0.1 dB, and a repeatability primarily determined by the number of(More)
The Microwave Component Analyzer (MCA) is introduced as a novel instrument for making automated signal-to-noise ratio (SNR) measurements in pulsed or CW mode. With an advanced vector demodulator, the MCA converts a microwave signal into error-corrected I (In-phase) and Q (Quadrature-phase) digitized signals. Utilizing a rotating phase reference technique,(More)
  • 1