J. A. DeGruyl

Electronically-Tunable, Low Noise Ka-Band Paramp-Downconverter Satellite Communications Receiver

H. C. Okean, J. A. DeGruyl, L. J. Steffek, 1975 .

Ultra Low Noise, Ku-Band Parametric Amplifier Assembly

H. C. Okean, J. A. DeGruyl, E. Ng, 1976 .

Helium-cooled Y-junction ferrite circulator switch

J. A. DeGruyl, S. Okwit, W. W. Heinz, 1963 .