5 research outputs found
Signal to noise measurement circuit
Phase lock reference provides a rapid and accurate method of determining the signal-to-noise ratio at the intermediate frequency stage of a receiver
Pseudo noise code and data transmission method and apparatus
Pseudo noise ranging codes, having a predetermined chipping rate, and a pair of binary data sources, each having a bit rate no greater than one tenth the chipping rate, quadriphase, digitally modulate a suppressed carrier wave having a first frequency are examined. Two additional binary data sources, each having a bit rate that is not restricted by the chipping rate of the first carrier, quadriphase, digitally modulate a suppressed carrier wave having a second frequency. The first and second frequencies are only slightly displaced so that there is overlap in the frequency bands which modulate the two carriers. The two suppressed carrier waves are linearly combined and transmitted from a first station to a second station so that the amplitude of the transmitted first wave is controlled so as not to degrade the detectability of the second wave at the second station
Signal coherence studies in multiaperture arrays
A two-element array was constructed to measure the gain improvement that can be realized while tracking spacecraft. Measurements were made at VHF and S band. An automatically controlled time delay correction system was developed and tested for this program
Ku-band high gain antenna
An exposed four element array of 12.8 m diameter elements mounted on a common pedestal is the recommended ground antenna configuration in support of the 2 GHz bandwidth Ku-band downlink from tdr satellites. The array provides three channel phase monopulse tracking capability with only listening feeds in each element. The array is as cost effective as a single aperture antenna and offers significant advantages in tracking and reliability
Variable-beamwidth antenna without moving parts
Basic configuration consists of large parabolic dish reflector, smaller hyperboloidal subreflector, and two sets of monopulse feeds located in conjugate focal region on boresight axis of dish