Pub Date : 2008-06-15DOI: 10.1109/MWSYM.2008.4632998
Xiaying Zhu, A. Hasib, N. Nikolova, M. Bakr
We propose a sensitivity solver for frequency-domain analysis engines based on volume methods such as the finite-element method. Our sensitivity solver computes S-parameter Jacobians directly from the field solution available from the electromagnetic simulation. The computational overhead is a fraction of that of the simulation itself. It is independent from the simulator’s grid, system equations and discretization method. It uses its own finite-difference grid and a sensitivity formula based on the frequency-domain finite-difference (FDFD) equation for the electric field. It computes the S-parameter gradients in the design parameter space through a self-adjoint formulation which eliminates adjoint system analyses and greatly simplifies implementation. We use our sensitivity solver in gradient-based optimization of filters. We achieve drastic reduction of the time required by the overall optimization process. All examples use a commercial finite-element simulator.
{"title":"Efficient electromagnetic optimization using self-adjoint Jacobian computation based on a central-node FDFD method","authors":"Xiaying Zhu, A. Hasib, N. Nikolova, M. Bakr","doi":"10.1109/MWSYM.2008.4632998","DOIUrl":"https://doi.org/10.1109/MWSYM.2008.4632998","url":null,"abstract":"We propose a sensitivity solver for frequency-domain analysis engines based on volume methods such as the finite-element method. Our sensitivity solver computes S-parameter Jacobians directly from the field solution available from the electromagnetic simulation. The computational overhead is a fraction of that of the simulation itself. It is independent from the simulator’s grid, system equations and discretization method. It uses its own finite-difference grid and a sensitivity formula based on the frequency-domain finite-difference (FDFD) equation for the electric field. It computes the S-parameter gradients in the design parameter space through a self-adjoint formulation which eliminates adjoint system analyses and greatly simplifies implementation. We use our sensitivity solver in gradient-based optimization of filters. We achieve drastic reduction of the time required by the overall optimization process. All examples use a commercial finite-element simulator.","PeriodicalId":273767,"journal":{"name":"2008 IEEE MTT-S International Microwave Symposium Digest","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126834662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-06-15DOI: 10.1109/MWSYM.2008.4633185
M. Jarrahi, T. Lee
A new scheme for a compact, continuously tunable terahertz source based on photoconductive antenna arrays is presented. Narrowband terahertz radiation is generated by superposition of time-delayed wideband radiations from an array of sub-picosecond photoconductive antennas. We demonstrate an 8 μW average power, radiation bandwidth of 0.05 THz, and a tuning range of 0.65–1.4 THz, through a 2.5×10 mm2 photoconductive antenna array prototype.
{"title":"High-power tunable terahertz generation based on photoconductive antenna arrays","authors":"M. Jarrahi, T. Lee","doi":"10.1109/MWSYM.2008.4633185","DOIUrl":"https://doi.org/10.1109/MWSYM.2008.4633185","url":null,"abstract":"A new scheme for a compact, continuously tunable terahertz source based on photoconductive antenna arrays is presented. Narrowband terahertz radiation is generated by superposition of time-delayed wideband radiations from an array of sub-picosecond photoconductive antennas. We demonstrate an 8 μW average power, radiation bandwidth of 0.05 THz, and a tuning range of 0.65–1.4 THz, through a 2.5×10 mm2 photoconductive antenna array prototype.","PeriodicalId":273767,"journal":{"name":"2008 IEEE MTT-S International Microwave Symposium Digest","volume":"142 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115092273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-06-15DOI: 10.1109/MWSYM.2008.4633115
Y. Nakasha, Y. Kawano, T. Suzuki, T. Ohki, T. Takahashi, K. Makiyama, T. Hirose, N. Hara
A wavelet generator (WG) based on simple ultra-wideband impulse radio (UWB-IR) architecture has been developed to use for multi-gigabit communications systems that utilize the W-band millimeter wave (75–110 GHz). The W-band WG radiates a pulse signal, or a wavelet, whose full width at half maximum is less than 80 ps, which makes it possible to realize a 12.5-Gb/s ON/OFF keying transmitter. The WG consists of only two components: a pulse generator (PG) and a band pass filter (BPF). The digital-based PG was fabricated by using 0.13-μm InP HEMTs and created a record short pulse of 7.6 ps and 0.8 Vpp. The BPF was designed to be a five-stage microstrip coupled line filter on an alumina substrate. The 3-dB pass band of the BPF was 78–93 GHz and its insertion loss was 1.5±0.1 dB. The group delay was 100±10 ps in the pass band. To the best of our knowledge, the WG is the first UWB-IR-based signal source that generates more than 10-Gb/s wavelets in the W-band.
{"title":"A W-band wavelet generator using 0.13-μm InP HEMTs for multi-gigabit communications based on ultra-wideband impulse radio","authors":"Y. Nakasha, Y. Kawano, T. Suzuki, T. Ohki, T. Takahashi, K. Makiyama, T. Hirose, N. Hara","doi":"10.1109/MWSYM.2008.4633115","DOIUrl":"https://doi.org/10.1109/MWSYM.2008.4633115","url":null,"abstract":"A wavelet generator (WG) based on simple ultra-wideband impulse radio (UWB-IR) architecture has been developed to use for multi-gigabit communications systems that utilize the W-band millimeter wave (75–110 GHz). The W-band WG radiates a pulse signal, or a wavelet, whose full width at half maximum is less than 80 ps, which makes it possible to realize a 12.5-Gb/s ON/OFF keying transmitter. The WG consists of only two components: a pulse generator (PG) and a band pass filter (BPF). The digital-based PG was fabricated by using 0.13-μm InP HEMTs and created a record short pulse of 7.6 ps and 0.8 Vpp. The BPF was designed to be a five-stage microstrip coupled line filter on an alumina substrate. The 3-dB pass band of the BPF was 78–93 GHz and its insertion loss was 1.5±0.1 dB. The group delay was 100±10 ps in the pass band. To the best of our knowledge, the WG is the first UWB-IR-based signal source that generates more than 10-Gb/s wavelets in the W-band.","PeriodicalId":273767,"journal":{"name":"2008 IEEE MTT-S International Microwave Symposium Digest","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116448950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-06-15DOI: 10.1109/MWSYM.2008.4633133
T. LaRocca, Sai-Wang Tam, Daquan Huang, Qun Gu, E. Socher, W. Hant, Frank Chang
Digital control of the effective dielectric constant of a differential mode transmission line is shown up to 60GHz in standard CMOS technology. The effective dielectric constant is shown to increase from 5 to over 50 for the fixed artificial dielectric case. The digital controlled artificial dielectric transmission line (DiCAD) uses MOS switches to dynamically control the phase. DiCAD achieves 50% of the physically available tuning range with effective dielectric constants varying between 7 and 28. Measured results favorably agree with full-wave electromagnetic simulations.
{"title":"Millimeter-wave CMOS digital controlled artificial dielectric differential mode transmission lines for reconfigurable ICs","authors":"T. LaRocca, Sai-Wang Tam, Daquan Huang, Qun Gu, E. Socher, W. Hant, Frank Chang","doi":"10.1109/MWSYM.2008.4633133","DOIUrl":"https://doi.org/10.1109/MWSYM.2008.4633133","url":null,"abstract":"Digital control of the effective dielectric constant of a differential mode transmission line is shown up to 60GHz in standard CMOS technology. The effective dielectric constant is shown to increase from 5 to over 50 for the fixed artificial dielectric case. The digital controlled artificial dielectric transmission line (DiCAD) uses MOS switches to dynamically control the phase. DiCAD achieves 50% of the physically available tuning range with effective dielectric constants varying between 7 and 28. Measured results favorably agree with full-wave electromagnetic simulations.","PeriodicalId":273767,"journal":{"name":"2008 IEEE MTT-S International Microwave Symposium Digest","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122569411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-06-15DOI: 10.1109/MWSYM.2008.4633260
P. Wright, A. Sheikh, C. Roff, P. Tasker, J. Benedikt
This paper investigates the development of an inverse class-F design procedure for obtaining very high efficiency performance at high power levels. RF waveform engineering was used to obtain high efficiency inverse class-F waveforms at the device current-generator plane. Drain efficiencies above 81% have been achieved at 0.9 and 2.1GHz for a wide band-gap gallium nitride (GaN) HEMT transistor and 12W fundamental output power. Investigations into improvements in drain efficiency through increases in drain bias voltage have yielded drain efficiencies of up to 84% at 2.1GHz. To the author’s knowledge, the efficiencies presented in this study are the highest published, measured efficiencies of a high power GaN HEMT at these frequencies.
{"title":"Highly efficient operation modes in GaN power transistors delivering upwards of 81% efficiency and 12W output power","authors":"P. Wright, A. Sheikh, C. Roff, P. Tasker, J. Benedikt","doi":"10.1109/MWSYM.2008.4633260","DOIUrl":"https://doi.org/10.1109/MWSYM.2008.4633260","url":null,"abstract":"This paper investigates the development of an inverse class-F design procedure for obtaining very high efficiency performance at high power levels. RF waveform engineering was used to obtain high efficiency inverse class-F waveforms at the device current-generator plane. Drain efficiencies above 81% have been achieved at 0.9 and 2.1GHz for a wide band-gap gallium nitride (GaN) HEMT transistor and 12W fundamental output power. Investigations into improvements in drain efficiency through increases in drain bias voltage have yielded drain efficiencies of up to 84% at 2.1GHz. To the author’s knowledge, the efficiencies presented in this study are the highest published, measured efficiencies of a high power GaN HEMT at these frequencies.","PeriodicalId":273767,"journal":{"name":"2008 IEEE MTT-S International Microwave Symposium Digest","volume":"302 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122693306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-06-15DOI: 10.1109/MWSYM.2008.4633278
M. Nedil, T. Denidni
In this paper, a novel ultra wideband directional coupler employing conductor backed coplanar waveguide CB-CPW and microstrip multilayer slot coupling technique is presented and implemented. The coupler uses two different transmission lines CB-CPW and microstrip, printed on two stacked substrate layers and coupled through a rectangular slot etched on a common ground plane located between these lines. Firstly, an analysis technique was used to obtain the coupler even and odd mode characteristic impedances. Secondly, using this approach, a new design of the directional coupler was performed. Simulation and experimental results show a good performance in terms of bandwidth, which covers the entire ultra-wideband operation (3.1–10.6 GHz).
{"title":"A new ultra wideband directional coupler based on a combination between CB-CPW and microstrip technologies","authors":"M. Nedil, T. Denidni","doi":"10.1109/MWSYM.2008.4633278","DOIUrl":"https://doi.org/10.1109/MWSYM.2008.4633278","url":null,"abstract":"In this paper, a novel ultra wideband directional coupler employing conductor backed coplanar waveguide CB-CPW and microstrip multilayer slot coupling technique is presented and implemented. The coupler uses two different transmission lines CB-CPW and microstrip, printed on two stacked substrate layers and coupled through a rectangular slot etched on a common ground plane located between these lines. Firstly, an analysis technique was used to obtain the coupler even and odd mode characteristic impedances. Secondly, using this approach, a new design of the directional coupler was performed. Simulation and experimental results show a good performance in terms of bandwidth, which covers the entire ultra-wideband operation (3.1–10.6 GHz).","PeriodicalId":273767,"journal":{"name":"2008 IEEE MTT-S International Microwave Symposium Digest","volume":"180 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122649899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-06-15DOI: 10.1109/MWSYM.2008.4633101
P. Basl, M. Bakr, N. Nikolova
The Adjoint Variable Method (AVM) is applied for the first time to perform sensitivity analysis for Transmission Line Modeling (TLM) using rubber cells with modified tensor properties. Rubber cells allow the conformal modeling of off-grid boundaries in the TLM domain using modified tensor properties. The scattering matrix of the rubber cell is analytically dependent on the dimensions of the modeled discontinuities. Using this property, an exact adjoint system is derived. The original and adjoint systems supply the necessary field information for the rubber cell based sensitivity calculations. Our technique is illustrated through sensitivity analysis and optimization of a waveguide bandpass filter.
{"title":"Efficient TLM sensitivity analysis exploiting rubber cells","authors":"P. Basl, M. Bakr, N. Nikolova","doi":"10.1109/MWSYM.2008.4633101","DOIUrl":"https://doi.org/10.1109/MWSYM.2008.4633101","url":null,"abstract":"The Adjoint Variable Method (AVM) is applied for the first time to perform sensitivity analysis for Transmission Line Modeling (TLM) using rubber cells with modified tensor properties. Rubber cells allow the conformal modeling of off-grid boundaries in the TLM domain using modified tensor properties. The scattering matrix of the rubber cell is analytically dependent on the dimensions of the modeled discontinuities. Using this property, an exact adjoint system is derived. The original and adjoint systems supply the necessary field information for the rubber cell based sensitivity calculations. Our technique is illustrated through sensitivity analysis and optimization of a waveguide bandpass filter.","PeriodicalId":273767,"journal":{"name":"2008 IEEE MTT-S International Microwave Symposium Digest","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116600896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-06-15DOI: 10.1109/MWSYM.2008.4633125
M. J. Inman, A. Elsherbeni
Graphical processing units (GPU) has been recently documented for the implementation of the FDTD technique. The use of these specialized processors for the implementation of numerical codes has been shown to significantly speed up the execution of these codes over standard CPU based solvers. With the execution of the FDTD method being reduced to a matter of seconds, the use of these codes for optimization and parameter exploration becomes possible. This paper will detail the use of a developed GPU based FDTD solver for both optimization and through a graphical interface parameter exploration.
{"title":"Optimization and parameter exploration using GPU based FDTD solvers","authors":"M. J. Inman, A. Elsherbeni","doi":"10.1109/MWSYM.2008.4633125","DOIUrl":"https://doi.org/10.1109/MWSYM.2008.4633125","url":null,"abstract":"Graphical processing units (GPU) has been recently documented for the implementation of the FDTD technique. The use of these specialized processors for the implementation of numerical codes has been shown to significantly speed up the execution of these codes over standard CPU based solvers. With the execution of the FDTD method being reduced to a matter of seconds, the use of these codes for optimization and parameter exploration becomes possible. This paper will detail the use of a developed GPU based FDTD solver for both optimization and through a graphical interface parameter exploration.","PeriodicalId":273767,"journal":{"name":"2008 IEEE MTT-S International Microwave Symposium Digest","volume":"189 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116868448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-06-15DOI: 10.1109/MWSYM.2008.4633147
Yang Zhang, Peng Liu, Tang-Nian Luo, Y. Chen, Deukhyoun Heo
This paper presents a novel low-voltage low-phase-noise LC quadrature voltage controlled oscillator (QVCO) implemented in the TSMC 0.18-μm CMOS process. By using a combination of bottom-series coupling architecture and capacitor tapping technique, the QVCO achieves a zero resonator phase shift (RPS), a high loaded resonator quality factor, and limited phase noise contribution from the current source, all of which lead to a low phase noise. From a 5.3-GHz carrier, the measured phase noise is −123 dBc/Hz at 1-MHz offset with a 1.8-V power supply and −118 dBc/Hz at 1-MHz offset with a 1-V power supply.
{"title":"A low-voltage low-phase-noise bottom-series LC QVCO using capacitor tapping technique","authors":"Yang Zhang, Peng Liu, Tang-Nian Luo, Y. Chen, Deukhyoun Heo","doi":"10.1109/MWSYM.2008.4633147","DOIUrl":"https://doi.org/10.1109/MWSYM.2008.4633147","url":null,"abstract":"This paper presents a novel low-voltage low-phase-noise LC quadrature voltage controlled oscillator (QVCO) implemented in the TSMC 0.18-μm CMOS process. By using a combination of bottom-series coupling architecture and capacitor tapping technique, the QVCO achieves a zero resonator phase shift (RPS), a high loaded resonator quality factor, and limited phase noise contribution from the current source, all of which lead to a low phase noise. From a 5.3-GHz carrier, the measured phase noise is −123 dBc/Hz at 1-MHz offset with a 1.8-V power supply and −118 dBc/Hz at 1-MHz offset with a 1-V power supply.","PeriodicalId":273767,"journal":{"name":"2008 IEEE MTT-S International Microwave Symposium Digest","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117095472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-06-15DOI: 10.1109/MWSYM.2008.4633263
M. Blech, Michael O. Benzinge, T. Eibert
A novel ultra-wideband (UWB) 2-dimensional angle of arrival (AOA) estimation technique is presented. Using a planar arrangement of one dielectric monocone antenna surrounded by four dielectric rod antennas all exhibiting an almost frequency independent beam pattern in the range of 2–4 GHz, precise 2-dimensional direction finding based on the amplitude monopulse principle is applicable. Thereby an average absolute angular error of 2° in a range of ±50° in both ϑ and ρ is achieved. Using two auxiliary dielectric rod antennas time difference of arrival (TDOA) based direction finding can also be employed, whereas the array dimensions can be kept very compact.
{"title":"2-dimensional ultra-wideband monopulse based direction finding","authors":"M. Blech, Michael O. Benzinge, T. Eibert","doi":"10.1109/MWSYM.2008.4633263","DOIUrl":"https://doi.org/10.1109/MWSYM.2008.4633263","url":null,"abstract":"A novel ultra-wideband (UWB) 2-dimensional angle of arrival (AOA) estimation technique is presented. Using a planar arrangement of one dielectric monocone antenna surrounded by four dielectric rod antennas all exhibiting an almost frequency independent beam pattern in the range of 2–4 GHz, precise 2-dimensional direction finding based on the amplitude monopulse principle is applicable. Thereby an average absolute angular error of 2° in a range of ±50° in both ϑ and ρ is achieved. Using two auxiliary dielectric rod antennas time difference of arrival (TDOA) based direction finding can also be employed, whereas the array dimensions can be kept very compact.","PeriodicalId":273767,"journal":{"name":"2008 IEEE MTT-S International Microwave Symposium Digest","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128532303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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