GigaHertz 2003. Proceedings from the Seventh Symposium
 M. A. Ali; S. C. Ortiz; T. Ivanov; A. Mortazawi; â€śAnalysis and Measurement of Hard-Horn Feeds for the Excitation of Quasi-Optical Amplifiersâ€ť; IEEE Trans. MTT; Vol.47; No.4; April 1999
 T. Ivanov; A. Mortazawi; â€śA Two-Stage Spatial Amplifier with Hard Horn Feedsâ€ť; IEEE Microwave and Guided Wave Letters; Vol.6; No.2; Feb. 1996
 M. Kim; J. J. Rosenberg; R. P. Smith; R. M. Weikle; J. B. Hacker; M. P. DeLisio and D. B. Rutledge; â€śA grid amplifierâ€ť; IEEE Microwave and Guided Wave Letters; Vol.1; No.11; Nov 1991
 M. Ozkar and A. Mortazawi; â€śAnalysis and design of an inhomogeneous transformer with hard wall waveguide sectionsâ€ť; IEEE Microwave and Guided Wave Letters; Vol.10; No.2; Feb. 2000.
 Per Simon Kildal and E. Lier; â€śHard horns improve cluster feeds of satellite antennasâ€ť; Electronics Letters; Vol.24; No.8; 14th April 1988.
 S. P. Skobelev; P-S Kildal; â€śAnalysis of arrays of rectangular waveguides radiating through stepwise transitions with dielectrically loaded hard walls in one planeâ€ť; Journal of Communications Technology and Electronics; Vol. 45; No 9; pp 964-969; Sept 2000.
 Lorenzo Acquarelli; â€śHard horn transition for use in a grid amplifierâ€ť; Master project at Chalmers University of Technology Summer/Autumn 2002 (Supervisor: P-S. Kildal); in cooperation with University of Siena over the Erasmus program.
 JosĂ© R. VerdĂş Lillo; â€śStudy of resonances in a hard waveguide cavity for quasioptical amplifierâ€ť; Master project at Chalmers University of Technology Summer/Autumn 2002 (Supervisor: P-S. Kildal); in cooperation with Universidad Europea de Madrid over the Erasmus program.