Millimeter-wave atmospheric loss prediction method

Relationship between atmospheric attenuation and the ground temperature and humidity provides a reference from which changes in temperature and humidity will produce a corresponding atmospheric loss figure. Computer program computes atmospheric loss due to water content, given the measured loss and ground temperature and humidity

Reflectometer for receiver input impedance match measurement Patent

Reflectometer for receiver input impedance match measuremen

Reflectometer for receiver input system

Reflectometer, built into a microwave input system, measures the match of devices in the waveguide system of tracking receivers. Match measurements can be made on a routine calibration basis. It was installed in the S-band receiving system in the feed cone of the 210-ft antenna

Microwave cryogenic thermal-noise standards

Field operational waveguide noise standard with nominal noise temperature of 78.09 plus/minus 0.12 deg K is calibrated more precisely than before. Calibration technique applies to various disciplines such as microwave radiometry, antenna temperature and loss measurement, and low-noise amplifier performance evaluation

Minimizing noise-temperature measurement errors

An analysis of noise-temperature measurement errors of low-noise amplifiers was performed. Results of this analysis can be used to optimize measurement schemes for minimum errors. For the cases evaluated, the effective noise temperature (Te) of a Ka-band maser can be measured most accurately by switching between an ambient and a 2-K cooled load without an isolation attenuator. A measurement accuracy of 0.3 K was obtained for this example

Cryogenic waveguide window is sealed with plastic foam

Waveguide windows made with polystyrene preformed plastic and sealed with foamed-in-place plastic are useful in any microwave waveguide system using cryogenic cooling

Giotto mission support

Deep Space Network (DSN) support of the Giotto mission to Comet Halley is summarized. The support is described beginning with the prelaunch testing and continues through the post comet encounter period

Non-linearity in measurement systems: Evaluation method and application to microwave radiometers

A simple method for determination and correction of nonlinaearity in measurement systems is presented. The technique is applicable to a wide range of measuring systems. The basic concept, an analysis, and a sample application are given. Nonlinearity of the Goldstone DSS 13 low noise HEMT 2.3 GHz (S-band) radiometer system results in noise temperature measurement errors. These errors are successfully correct with this method

A radiometric method for measuring the insertion loss of radome materials

Radiometer system measures effective noise temperature directed towards sky, with and without radome over antenna horn. Data is then translated into computer format. With additional transmission line insertion loss data from other measurements, computer calculates insertion loss of radome material

Double-throw microwave device switches two lines quickly

By combining a single-throw microwave switch with a microwave circulator in a circuit, two input lines can be switched quickly. There is only a brief transition time when both /or neither/ of the two lines are connected to an output line