Jon B. Hacker

Learn More
We report 220 GHz Solid State Power Amplifier (SSPA) using a 250nm Indium Phosphide HBT technology. Amplifiers reported include designs having 2 and 4 power combined cells. The 4-cell amplifiers exhibited 10 dB small signal gain and 48.8 mW of output power with 4.5 dB gain at 220 GHz. These amplifiers have a 3-dB small signal bandwidth of greater than 48(More)
When 23 accessions of pearl millet growing in 1990 at Gatton, south-eastern Queensland, were examined for virus infection, all accessions had plants with mosaic symptoms. Using sorghum differential test plants, it was shown that Johnsongrass mosaic virus (JGMV) was commonly associated, but one isolate of the sabi grass strain of sugarcane mosaic virus(More)
The use of esterase isozymes for the detection of inter- and intra-specific hybrids between five diploid accessions of the grass genus Digitaria (section Erianthae) was investigated. Variation was observed between accessions and between plants within accessions. Segregation patterns in selfed progeny and in crosses between parents differing by a(More)
Variation in seed production and its components was investigated between and within four cultivars of the pasture grass Setaria sphacelata, in two experiments over two years, as a basis for future cultivar improvement. The study sought to determine the basis for the considerable differences in seed production of the four cultivars Nandi, Narok, Solander and(More)
Digitaria eriantha is a subtropical grass which is widely sown as a pasture species in South Africa and cultivars have recently been released in Australia. The species is variable in seed production and in other agronomic attributes. This paper describes a breeding program designed to combine the seed production of cv. Premier with the high productivity in(More)
Two experiments are discussed. In the first, rates of root elongation during the first four days of growth at 25 °C were studied in Chamaecrista rotundifolia (34 accessions), C. nictitans (2 accessions), C. pilosa (1 accession) and C. serpens (3 accessions). In the second, a comparison was made of germination characteristics of 14 accessions of C.(More)
  • 1