@article{tai_abbasi_ricketts_2018, title={Analysis and design of high-power and efficient, millimeter-wave power amplifier systems using zero degree combiners}, volume={105}, ISSN={["1362-3060"]}, DOI={10.1080/00207217.2017.1335798}, abstractNote={ABSTRACT We present the analysis and design of high-power millimetre-wave power amplifier (PA) systems using zero-degree combiners (ZDCs). The methodology presented optimises the PA device sizing and the number of combined unit PAs based on device load pull simulations, driver power consumption analysis and loss analysis of the ZDC. Our analysis shows that an optimal number of N-way combined unit PAs leads to the highest power-added efficiency (PAE) for a given output power. To illustrate our design methodology, we designed a 1-W PA system at 45 GHz using a 45 nm silicon-on-insulator process and showed that an 8-way combined PA has the highest PAE that yields simulated output power of 30.6 dBm and 31% peak PAE.}, number={1}, journal={INTERNATIONAL JOURNAL OF ELECTRONICS}, author={Tai, Wei and Abbasi, Mortez and Ricketts, David S.}, year={2018}, pages={1–11} }
 @inproceedings{shen_aiken_abbasi_parekh_zhao_dickey_ricketts_2017, title={Rapid prototyping of low loss 3D printed waveguides for millimeter-wave applications}, DOI={10.1109/mwsym.2017.8058593}, abstractNote={Traditional hollow metallic waveguide manufacturing techniques are readily capable of producing components with high-precision geometric tolerances, yet generally lack the ability to customize individual parts on demand or to deliver finished components with low lead times. This paper proposes a Rapid-Prototyping (RP) method for relatively low-loss millimeter-wave hollow waveguides produced using consumer-grade stere-olithographic (SLA) Additive Manufacturing (AM) technology, in conjunction with an electroless metallization process optimized for acrylate-based photopolymer substrates. To demonstrate the capabilities of this particular AM process, waveguide prototypes are fabricated for the W- and D-bands. The measured insertion loss at W-band is between 0.12 dB/in to 0.25 dB/in, corresponding to a mean value of 0.16 dB/in. To our knowledge, this is the lowest insertion loss figure presented to date, when compared to other W-Band AM waveguide designs reported in the literature. Printed D-band waveguide prototypes exhibit a transducer loss of 0.26 dB/in to 1.01 dB/in, with a corresponding mean value of 0.65 dB/in, which is similar performance to a commercial metal waveguide.}, booktitle={2017 ieee mtt-s international microwave symposium (ims)}, author={Shen, J. Y. and Aiken, M. W. and Abbasi, M. and Parekh, D. P. and Zhao, X. and Dickey, Michael and Ricketts, D. S.}, year={2017}, pages={41–44} }
 @article{carpenter_nopchinda_abbasi_he_bao_eriksson_zirath_2016, title={A D-Band 48-Gbit/s 64-QAM/QPSK direct-conversion I/Q transceiver chipset}, volume={64}, number={4}, journal={IEEE Transactions on Microwave Theory and Techniques}, author={Carpenter, S. and Nopchinda, D. and Abbasi, M. and He, Z. S. and Bao, M. Q. and Eriksson, T. and Zirath, H.}, year={2016}, pages={1285–1296} }
 @inproceedings{harris_nicholst_abbasi_ricketts_2016, title={A Versatile mm-wave micromachined anti-reflective layer}, DOI={10.1109/apmc.2016.7931298}, abstractNote={Micromachined millimeter-wave anti-reflective layers (mm-AR) offer a highly customizable and effective method to maximize power transmission through dielectric media. The power transmitted through an air-dielectric interface is maximized by adding an anti-reflective layer whose thickness is a quarter-wavelength and whose dielectric constant is the geometric mean of air and the dielectric, in analogous fashion to a quarter-wave transformer in transmission line theory. The mm-AR is an artificial dielectric material with controlled thickness and dielectric constant. A DRIE process forms a sub-wavelength lattice in a substrate that controls the material's effective dielectric response. The resulting anti-reflective layers were used to improve transmission through a silicon-air interface from an average of 40% across the W-band to 95%. While silicon was used in this work, the demonstrated impedance matching technique can be used for a wide variety of dielectric materials.}, booktitle={2016 asia-pacific microwave conference (apmc2016)}, author={Harris, W. and Nicholst, T. and Abbasi, M. and Ricketts, D.}, year={2016} }
 @article{besnoff_abbasi_ricketts_2016, title={High data-rate communication in near-field RFID and wireless power using higher order modulation}, volume={64}, number={2}, journal={IEEE Transactions on Microwave Theory and Techniques}, author={Besnoff, J. and Abbasi, M. and Ricketts, D. S.}, year={2016}, pages={401–413} }
 @inproceedings{abbasi_ricketts_2016, title={W-band corrugated and non-corrugated conical horn antennas using stereolithography 3D-printing technology}, DOI={10.1109/apmc.2016.7931300}, abstractNote={we are ideally looking for a cost-effective fabrication technique for any form structure light-weigh repeatable}, booktitle={2016 asia-pacific microwave conference (apmc2016)}, author={Abbasi, M. and Ricketts, D. S.}, year={2016} }
 @inproceedings{abbasi_ricketts_2016, title={mm-wave and THz multipliers: Advances and opportunities}, DOI={10.1109/apmc.2016.7931425}, abstractNote={This paper introduces a new way of evaluating performance of mm-wave integrated multiplier chains based on the power efficiency. Although superior performance of III–V technologies are acknowledged, focus of the paper will be on Silicon circuits which are more suited for large-scale multi-element integrated arrays. It will be discussed that power efficiency of the multiplier chain including the dc power required for generating the input RF signal is a very important metric for selecting the topology and configuration of the system. We will demonstrate that proper choice of topology as well as optimized circuit design yield state-of-the art output power at 260GHz–280GHz in SiGe and CMOS circuits.}, booktitle={2016 asia-pacific microwave conference (apmc2016)}, author={Abbasi, M. and Ricketts, D. S.}, year={2016} }
 @article{abbasi_ricketts_2015, title={275-285 GHz balanced frequency quadrupler chain in 45 nm SOI CMOS}, volume={51}, ISSN={["1350-911X"]}, DOI={10.1049/el.2015.2100}, abstractNote={A 280 GHz broadband balanced frequency quadrupler chain is presented. The quadrupler can be used to generate as high as 200 μW over a −3 dB bandwidth of 275–285 GHz, which enables emerging applications in sub-millimetre-wave communications and remote sensing. The circuit is designed and fabricated in a 45 nm silicon on insulator (SOI) CMOS technology and occupies an area of 0.21 mm2 including the pads. The chip consumes 85 mA dc current from a 1.1 V supply.}, number={18}, journal={ELECTRONICS LETTERS}, author={Abbasi, M. and Ricketts, D. S.}, year={2015}, month={Sep} }
 @article{abbasi_ricketts_2016, title={A high-power, broadband 245-285 GHz balanced frequency doubler in 45 nm SOI CMOS}, volume={58}, ISSN={["1098-2760"]}, DOI={10.1002/mop.29586}, abstractNote={ABSTRACTA compact, broadband balanced frequency doubler that achieves state‐of‐the‐art output power with a usable bandwidth of over 40 GHz (245–285 GHz) has been presented. This wide bandwidth is twice that of previously published CMOS doublers from 140 to 340 GHz, enabling emerging applications in wide bandwidth communication and radar at sub‐THz frequencies. The doubler is designed and fabricated in a 45 nm SOI CMOS technology with an effective area of only 0.12 mm2. The frequency doubler exhibits −15 ± 1.5 dB conversion loss over 40 GHz bandwidth and can provide as high as 200 μW power while consuming 19 ± 1 mW dc power from a 1.1 V supply. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:423–426, 2016}, number={2}, journal={MICROWAVE AND OPTICAL TECHNOLOGY LETTERS}, author={Abbasi, Morteza and Ricketts, David S.}, year={2016}, month={Feb}, pages={423–426} }