[ { "id": "authors:rxf61-srv59", "collection": "authors", "collection_id": "rxf61-srv59", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221003-756400000.18", "type": "article", "title": "Variable-Phase-Shift Based High Data Rate Sub-THz FSK Transmitter Design: Theory and Implementation", "author": [ { "family_name": "Chen", "given_name": "Lili", "orcid": "0000-0001-6398-2388", "clpid": "Chen-Lili" }, { "family_name": "Nooshabadi", "given_name": "Samir", "orcid": "0000-0003-1645-0009", "clpid": "Nooshabadi-Samir" }, { "family_name": "Cathelin", "given_name": "Andreia", "orcid": "0000-0003-2745-4523", "clpid": "Cathelin-Andreia" }, { "family_name": "Afshari", "given_name": "Ehsan", "orcid": "0000-0002-4528-1788", "clpid": "Afshari-Ehsan" } ], "abstract": "Targeting the new generation of high data rate communication systems at sub-terahertz (THz), a fully integrated, energy and area efficient, 196 GHz frequency-shift keying (FSK) transmitter was designed and prototyped in a 55-nm SiGe process. By analyzing the transient dynamics of a loop of coupled oscillators, a new direct modulation technique for frequency modulation is presented. It is shown that an instantaneous frequency shift can be realized in theory as long as the coupling mode of the coupled oscillators loop system does not change. By controlling the phase shift in a system of tunable couplers, a 10 Gb/s single channel data rate wireless link was demonstrated, which is the first FSK wireless transmitter at sub-THz frequencies, and is 5\u00d7 higher compared with all other previously published CMOS/BiCMOS wireless FSK transmitters. The achieved single channel data rate and energy efficiency per bit are comparable to other recently published sub-THz transmitters with more complicated modulation schemes like M-ary amplitude-shift keying (ASK), phase-shift keying (PSK), or quadratic-amplitude modulation (QAM).", "doi": "10.1109/tmtt.2022.3205332", "issn": "0018-9480", "publisher": "IEEE", "publication": "IEEE Transactions on Microwave Theory and Techniques", "publication_date": "2022-10-05" }, { "id": "authors:pyq27-2av73", "collection": "authors", "collection_id": "pyq27-2av73", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210626-183437398", "type": "article", "title": "An ultra-fast frequency shift mechanism for high data-rate sub-THz wireless communications in CMOS", "author": [ { "family_name": "Chen", "given_name": "Lili", "orcid": "0000-0001-6398-2388", "clpid": "Chen-Lili" }, { "family_name": "Nooshabadi", "given_name": "Samir", "orcid": "0000-0003-1645-0009", "clpid": "Nooshabadi-Samir" }, { "family_name": "Khoeini", "given_name": "Farzad", "orcid": "0000-0003-0249-6516", "clpid": "Khoeini-Farzad" }, { "family_name": "Khalifa", "given_name": "Zainulabideen", "clpid": "Khalifa-Zainulabideen" }, { "family_name": "Hadidian", "given_name": "Bahareh", "orcid": "0000-0002-7840-588X", "clpid": "Hadidian-Bahareh" }, { "family_name": "Afshari", "given_name": "Ehsan", "orcid": "0000-0002-4528-1788", "clpid": "Afshari-Ehsan" } ], "abstract": "Various approaches are being considered to address the demand for high-throughput (Gb/s) point-to-point wireless communication systems in 5G infrastructure and sub-THz transceivers. Two fully integrated CMOS wireless transmitters with frequency shift keying (FSK) modulation were prototyped in a standard 55\u2009nm SiGe process. Benefiting from the coupled oscillator loop system, the single channel data rate up to 10\u2009Gb/s wireless link (limited by measurement equipment) was demonstrated. The proposed coupled oscillator loop system enables instantaneous frequency shift in an ideal situation, which resolves overshoots/undershoots and long frequency settling issues in the conventional varactor-based LC voltage controlled oscillator. The measured single channel data rate is around 5\u00d7 higher than the previously published CMOS/BiCMOS FSK transmitter.", "doi": "10.1063/5.0055503", "issn": "0003-6951", "publisher": "American Institute of Physics", "publication": "Applied Physics Letters", "publication_date": "2021-06-14", "series_number": "24", "volume": "118", "issue": "24", "pages": "Art. No. 242103" }, { "id": "authors:tq3ks-7hm80", "collection": "authors", "collection_id": "tq3ks-7hm80", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210826-145320066", "type": "book_section", "title": "A Compact 196 GHz FSK Transmitter for Point-to-Point Wireless Communication with Novel Direct Modulation Technique", "book_title": "2021 IEEE Radio Frequency Integrated Circuits Symposium (RFIC)", "author": [ { "family_name": "Chen", "given_name": "Lili", "orcid": "0000-0001-6398-2388", "clpid": "Chen-Lili" }, { "family_name": "Nooshabadi", "given_name": "Samir", "orcid": "0000-0003-1645-0009", "clpid": "Nooshabadi-Samir" }, { "family_name": "Cathelin", "given_name": "Andreia", "clpid": "Cathelin-Andreia" }, { "family_name": "Afshari", "given_name": "Ehsan", "orcid": "0000-0002-4528-1788", "clpid": "Afshari-Ehsan" } ], "abstract": "A compact, fully-integrated 196GHz FSK transmitter for point-to-point wireless communication is prototyped with a 55nm SiGe BiCMOS process, demonstrating a single-channel data rate of 10Gb/s with a chip area of 0.68mm\u00b2. The achieved single-channel data rate is around 5x higher compared with all other FSK wireless transmitters and the chip area is around 4x smaller compared with other state-of-the-art sub-THz wireless transmitters. Unlike conventional FSK transmitters which encode data with two oscillators at different frequencies or with the control voltage of varactors in the LC tank, the proposed FSK transmitter performs data modulation by varying the phase shift of tunable phase shifting couplers in a coupled oscillator loop, resolving the issues of extra power consumption and long frequency settling time. In theory, frequency shift based on this mechanism is instantaneous without overshoot/undershoot issues.", "doi": "10.1109/rfic51843.2021.9490475", "isbn": "978-1-6654-2549-0", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2021-06", "pages": "11-14" } ]