@article{jiang_ortiz_mortazawi_2004, title={A Ka-band power amplifier based on the traveling-wave power-dividing/combining slotted-waveguide circuit}, volume={52}, ISSN={["1557-9670"]}, DOI={10.1109/TMTT.2003.822026}, abstractNote={An eight-device Ka-band solid-state power amplifier has been designed and fabricated using a traveling-wave power-dividing/combining technique. The low-profile slotted-waveguide structure employed in this design provides not only a high power-combining efficiency over a wide bandwidth, but also efficient heat sinking for the active devices. The measured maximum small-signal gain of the eight-device power amplifier is 19.4 dB at 34 GHz with a 3-dB bandwidth of 3.2 GHz (f/sub L/=31.8 GHz, f/sub H/=35 GHz). The measured maximum output power at 1-dB compression (P/sub out/ at 1 dB) from the power amplifier is 33 dBm (/spl sim/2 W) at 32.2 GHz, with a power-combining efficiency of 80%. Furthermore, performance degradation of this power amplifier due to device failures has also been simulated and measured.}, number={2}, journal={IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES}, author={Jiang, X and Ortiz, SC and Mortazawi, A}, year={2004}, month={Feb}, pages={633–639} }
 @article{jin_ortiz_mortazawi_2004, title={Design and performance of a new digital phase shifter at X-band}, volume={14}, ISSN={["1531-1309"]}, DOI={10.1109/LMWC.2004.832049}, abstractNote={A new digital phase shifter design at X-band is presented. The phase shifter operates based on converting a microstrip line to a rectangular waveguide and thus achieving the phase shift by changing the wave propagation constant through the medium. As a proof of principle, a 3-b phase shifter has been designed and constructed using PIN diode switches. An average insertion loss of 1.95 dB and phase shift error of less than 4/spl deg/ at 10.6 GHz are achieved.}, number={9}, journal={IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS}, author={Jin, Z and Ortiz, S and Mortazawi, A}, year={2004}, month={Sep}, pages={428–430} }
 @article{jiang_liu_ortiz_bashirullah_mortazawi_2003, title={A K a-band power amplifier based on a low-profile slotted-waveguide power-combining/dividing circuit}, volume={51}, ISSN={["1557-9670"]}, DOI={10.1109/TMTT.2002.806927}, abstractNote={In this paper, a Ka-band power amplifier based on a resonant slotted-waveguide-to-microstrip power-dividing/combining circuit is presented. The advantages of this structure are its low profile, ease of fabrication, as well as its potential for high power-combining efficiency. In addition, efficient heat sinking of monolithic microwave integrated circuit (MMIC) devices is achieved. A slotted-waveguide power amplifier using eight MMIC amplifiers was designed and fabricated. The measured power-combining efficiency at 33 GHz is 72%. In addition, simulation results predicting the performance degradation of the slotted-waveguide power amplifier due to multiple device failure are presented.}, number={1}, journal={IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES}, author={Jiang, X and Liu, L and Ortiz, SC and Bashirullah, R and Mortazawi, A}, year={2003}, month={Jan}, pages={144–147} }
 @article{batty_christoffersen_yakovlev_whitaker_mortazawi_al-zayed_ozkar_ortiz_reano_yang_et al._2002, title={Global coupled EM-electrical-thermal simulation and experimental validation for a spatial power combining MMIC array}, volume={50}, ISSN={["1557-9670"]}, DOI={10.1109/TMTT.2002.805142}, abstractNote={The first fully coupled electromagnetic-electro-thermal global simulation of a large microwave subsystem, here a whole spatial power combining MMIC array, is described. The modeling effort is supported by parallel developments in electro-optic and thermal measurement. The CAD tools and experimental characterisation described, provide a unique capability for the design of quasi-optical systems and for the exploration of the fundamental physics of spatial power combining devices.}, number={12}, journal={IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES}, author={Batty, W and Christoffersen, CE and Yakovlev, AB and Whitaker, JF and Mortazawi, A and Al-Zayed, A and Ozkar, M and Ortiz, SC and Reano, RM and Yang, K and et al.}, year={2002}, month={Dec}, pages={2820–2833} }
 @article{ortiz_ivanov_mortazawi_2000, title={A CPW-fed microstrip patch quasi-optical amplifier array}, volume={48}, ISSN={["0018-9480"]}, DOI={10.1109/22.821775}, abstractNote={A CPW fed microstrip patch quasi-optical power combining amplifier array is introduced. The amplifier array uses CPW fed patches for both input and output antennas. This structure is not only compatible with MMIC implementations but can also provide a greater bandwidth for the patch antennas. A 4/spl times/4 amplifier array was designed and fabricated at X-band. Theoretical and experimental results are presented.}, number={2}, journal={IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES}, author={Ortiz, SC and Ivanov, T and Mortazawi, A}, year={2000}, month={Feb}, pages={276–280} }
 @article{yakovlev_ortiz_ozkar_mortazawi_steer_2000, title={A waveguide-based aperture-coupled patch amplifier array - Full-wave system analysis and experimental validation}, volume={48}, ISSN={["0018-9480"]}, DOI={10.1109/22.899032}, abstractNote={In this paper, the full-wave analysis and experimental verification of a waveguide-based aperture-coupled patch amplifier array are presented. The spatial power-combining amplifier array is modeled by the decomposition of the entire system into several electromagnetically coupled modules. This includes a method of moments integral equation formulation of the generalized scattering matrix (GSM) for an N-port waveguide-based patch-to-slot transition; a mode-matching analysis of the GSM for the receiving and transmitting rectangular waveguide tapers; and a finite-element analysis of the waveguide-to-microstrip line junctions. An overall response of the system is obtained by cascading GSMs of electromagnetic structures and the S-parameters of amplifier networks. Numerical and experimental results are presented for the single unit cell and 2/spl times/3 amplifier array operating at X-band. The results are shown for the rectangular aperture-coupled patch array, although the analysis is applicable to structures with arbitrarily shaped planar electric and magnetic surfaces.}, number={12}, journal={IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES}, author={Yakovlev, AB and Ortiz, S and Ozkar, M and Mortazawi, A and Steer, MB}, year={2000}, month={Dec}, pages={2692–2699} }
 @article{ali_ortiz_ivanov_mortazawi_1999, title={Analysis and measurement of hard-horn feeds for the excitation of quasi-optical amplifiers}, volume={47}, ISSN={["0018-9480"]}, DOI={10.1109/22.754882}, abstractNote={Measurement and analysis of hard horn feeds for excitation of quasi-optical amplifiers has been performed. A computer program based on the mode matching technique has been developed in order to determine the aperture field distribution for pyramidal hard horns. This program can be used to optimize a hard horn's field distribution and bandwidth. Simulation and measurement results for a 31 GHz hard horn feed are presented.}, number={4}, journal={IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES}, author={Ali, MA and Ortiz, SC and Ivanov, T and Mortazawi, A}, year={1999}, month={Apr}, pages={479–487} }