Engineering topics
Publications and source records attributed to Lang, G. J..
Near field antenna measurements as an alternative to far field measurements are discussed. Most of the serious shortcomings of far field measurements can be alleviated using near field techniques. The near field data can be used as a direct diagnostic of antenna performance before the integration by the aperture which can make it difficult to isolate the cause of far field pattern anomalies.
The planetary radio astronomy (PRA) experiment on the Voyager spacecraft will measure the amplitude, spectrum, time variations, and polarization of radio emissions over a frequency range of 1.2 kHz to 40.5 MHz with the aid of the PRA receiver (PRAR) and two 10-m orthogonal monopoles. Sensitivity and dynamic range will allow observation of a wide range of Jovian emissions from near earth to encounter. This paper describes the system elements, including the preamp/attenuator/calibrator, the LF polarization discriminator, the four LF-IF amplifier stages, the HF polarization discriminator, the translation LO, the log-IF and detector, the frequency synthesizer, the data processor, control system, power supply, and antennas.