Li H.,University of Virginia |
Arsenovic A.,University of Virginia |
Hesler J.L.,Virginia Diodes, Inc. |
Kerr A.R.,U.S. National Radio Astronomy Observatory |
Weikle R.M.,University of Virginia
IEEE Transactions on Terahertz Science and Technology | Year: 2014
This paper presents a study characterizing the connection repeatability and reflection coefficient of submillimeter waveguide flanges in the 500-750 GHz band (WR-1.5 or WM-380). The connection repeatability of four types of flange was measured using one-port measurements and a 'load-reference' technique with a vertically mounted system to mitigate gravitational bias. To measure the error-corrected complex reflection coefficients of pairs of waveguide flanges, a calibration procedure insensitive to flange misalignment was used. This SDD(RO) calibration method employs four standards: a flush short, two delay shorts with different but unspecified offsets, and a radiating open-ended waveguide. The uncertainty associated with this calibration method is investigated and it is used to estimate the reflection coefficient resulting from flange misalignment. © 2013 IEEE.
Hesler J.,Virginia Diodes, Inc. |
Hui K.,Virginia Diodes, Inc. |
Crowe T.,Virginia Diodes, Inc.
2012 IEEE International Topical Meeting on Microwave Photonics, MWP 2012 - Proceedings | Year: 2012
The optimization of THz Schottky diode detectors for use in wireless communications will be described. Output modulation bandwidths of 30 GHz at 100 GHz and 40 GHz at 300 GHz have been demonstrated. The integration of output amplifiers into the detector housing will be described. © 2012 IEEE.
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 150.00K | Year: 2011
The ITER ECE Radiometer system is envisioned to cover the frequency range from about 200- 300GHz with a set of three high reliability receivers. Each receiver will use a fixed frequency local oscillator source and a very broad IF bandwidth. The primary technical challenges are achieving flat performance across the IF band and ensuring a level of reliability that will assure system performance during critical ITER experiments. The IF bandwidth and reliability requirements of ITER create technical requirements that have not yet been achieved. The primary goal of this SBIR project is to demonstrate and deliver to the ITER program an all-solidstate receiver system that achieves all of the primary technical requirements for the ITER ECE Radiometer system. The proposed solution uses three independent receiver systems to span the 100GHz bandwidth required for ITER. These receivers will be based on a VDI receiver that has already been developed for the Alcator C-MOD ECE Radiometer. The primary technical challenges for ITER are to achieve flat receiver performance across the planned 40GHz IF band, and to fundamentally improve the reliability of the complete receiver system. The improvements in reliability will begin with a thorough evaluation of the reliability of the present receiver technology. Each of the components will be thoroughly evaluated and upgraded to meet the ITER requirements. Also a higher level of integration will be used for key components and the system as a whole. Commercial Applications and Other Benefits: The broadband and reliable receiver technology developed through this SBIR project will find applications spanning from basic science, through defense and security, industrial process control and medicine. Primary examples include radio-astronomy, chemical spectroscopy, atmospheric studies, plasma diagnostics for process control, short range and secure communications, the detection of chemical and biological threats and imaging systems. For example, passive imaging systems for portal security will benefit from the increased IF bandwidth. The broader IF bandwidth will also allow researchers developing short range communications links to achieve greater data rates. The increased reliability of the components and receiver systems will also be used in all of VDIs commercial products. For example, VDIs emerging commercial product line of frequency extenders for vector network analyzers and spectrum analyzers are a new tool for the development of improved devices, components and systems in the terahertz frequency range. The reliability improvements developed through this SBIR project will fundamentally improve the reliability and commercial viability of VDIs test and measurement products
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 125.00K | Year: 2014
This proposal is responsive to NASA SBIR Subtopic S1.02: Microwave Technologies for Remote Sensing, 640GHz Polarimeter. VDI has recently demonstrated the integration of a WR10 Mixer-Amplifier Multiplier chain (MixAMC), including the LO and IF amplifier MMICs, into a single waveguide housing. The focus of the proposed research is the extension these innovative integration technologies to include additional components required for atmospheric radiometers, and to extend the resulting technology across the frequency band of interest to NASA. Such integration will fundamentally improve the size, weight, reliability and cost of terahertz receivers. Additionally, the integration of a newly available low noise MMIC amplifier at the front-end of the receiver will allow these improvements to be achieved with an overall reduction in the power requirements and an increase in receiver sensitivity. At the end of the Phase 2 VDI will deliver to NASA a very compact and reliable receiver system suitable for polarimetric measurements at 640GHz. The ultimate result of this SBIR program will be the commercial availability of compact, reliable and cost effective receiver systems throughout the frequency range of interest for atmospheric remote sensing, including polarimetric measurement capabilities. Additionally, the new compact receivers will be compatible with CubeSats, which are expected to play a very important role in future atmospheric remote sensing missions.
Agency: Department of Defense | Branch: Army | Program: SBIR | Phase: Phase I | Award Amount: 99.25K | Year: 2013
VDI and OSU are in a strong position to meet the requirements of this SBIR. Building on a strong foundation of closely related sensor work in the millimeter/submillimeter, we will focus our Phase I efforts on the new challenges of this SBIR topic. The chief new analysis challenge is to provide a list of lines that arise from gases that are not in the spectrometer reference catalog. We have already demonstrated the absolute intensity calibration and well defined lineshapes required for the subtraction and deconvolution that are a necessary foundation for this task. To satisfy these requirements and to broaden the range of applications, we have chosen high spectral purity, frequency agile hardware and configurable software. The hardware design will allow multiple frequency bands and flexible physical configurations. This design uses all-solid-state electronic component technologies developed by VDI and demonstrated throughout the frequency band of interest.
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 124.99K | Year: 2016
This proposal is responsive to NASA SBIR Subtopic S1.02: Microwave Technologies for Remote Sensing, specifically the interest in the development of a 640 GHz Heterodyne Polarimeter with I, Q, U Channels. Suitably compact, light-weight and power efficient heterodyne instruments are required to enable polarimetric measurements for microphysical parameterization of ice clouds applicable to NASA's planned Aerosol, Cloud and Ecosystems (ACE) mission. VDI will develop and demonstrate a compact heterodyne receiver technology that achieves the polarimetric capability required for ACE and other atmospheric remote sensing instruments throughout the frequency range from 100 GHz to about 1 THz. Through the Phase 1 effort, VDI will demonstrate the feasibility of achieving the 640 GHz polarimetric receiver capability required by NASA. This effort will include the development and characterization of a 640 GHz orthomode transducer (OMT), the demonstration of a 640 GHz low-noise amplifier, and the assembly and testing of a complete polarimetric receiver. Although the Phase 1 prototype will use discrete components (OMT, LNA, mixer, and multipliers); all of these components will be designed for full integration in Phase 2.
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 1.00M | Year: 2012
The US role in ITER is focused on the key diagnostic instruments, such as the Electron Cyclotron Emission (ECE) Radiometer. Present concepts for this instrument require a compact and reliable receiver that yields instantaneous coverage of the 200-300GHz frequency range. Presently available millimeter-wave receivers are unable to meet this requirement. Virginia Diodes proposes a system of three state-of-the-art heterodyne receivers, each of which will cover one-third of the desired ITER band. The input waveguides of these receivers will be combined into a single guide using an innovative waveguide triplexer. A quasi-optical system will couple the triplexer to the ITER system. The most important innovations in the project are VDIs efforts to fundamentally improve the performance and reliability of the receivers. These include a new fabrication technology for the diode integrated circuits and methods to improve the IF bandwidth of the mixers. VDI successfully demonstrated the proposed IC fabrication technology, demonstrated the IF bandwidth required for the ITER receivers while increasing also reliability, and conducted an initial reliability study of the receiver technology. The basic technology for the waveguide triplexer was also demonstrated. The Phase 2 plan culminates in the demonstration and delivery of a functional receiver system for the ITER ECE Radiometer system. Primary research areas include; the development of a highly integrated receiver architecture using both the new diode integrated circuit technology and the integration of many circuit functions into the same housing, the development of the new waveguide triplexer, the development and evaluation of the three receiver systems, the demonstration of the complete ITER system, and a thorough study of reliability of all system components and sub-systems. Commercial Applications and Other Benefits: Terahertz technology is an emerging field with a broad array of scientific, military, medical and commercial applications. The development of broader band and more reliable receivers is a primary requirement for the continued growth of this field.
Agency: Department of Homeland Security | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 750.00K | Year: 2010
Modular system will be developed to extend the frequency range of Vector Network Analyzers to at least 1 THz. These extenders will offer excellent dynamic range and stability, as well as the capability for fully calibrated measurements. The extenders will rely on innovative full waveguide band frequency multipliers and mixers that utilize planar, integrated Schottky diode circuits. The modular extender systems will allow rapid reconfiguration of the components for operation in multiple waveguide bands, while maintaining low cost. During Phase 1 VDI demonstrated the modular extender concepts and delivered a WR2.2 frequency extender with exceptional dynamic range and excellent stability. Phase 2 will emphasize the development of modular extenders for the complete 100GHz to 1,000GHz frequency band. This includes development of the individual components that most affect system performance, as well as the development of the extender systems to yield reliable and cost effective products. The deliverable system, covering 100GHz to 1,000GHz, will serve as a prototype for the sales of VNA extenders for the wider commercial market; which includes national, industrial and university research laboratories that are developing new technologies and applications for the terahertz frequency band.
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 1.00M | Year: 2010
The US role in ITER is focused on the key diagnostic instruments, such as the Low Field Side (LFS) Reflectometer. Present concepts for this instrument require an all-solid
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 124.91K | Year: 2015
This proposal is responsive to NASA SBIR Subtopic S1.02: Microwave Technologies for Remote Sensing, specifically the interest in frequency multipliers that can work in the 200-400GHz range (output frequency) with better than 30% efficiency and input powers up to 1W. VDI will employ three specific innovations to achieve the power and efficiency goals described in the solicitation. 1) Optimization of the use of diamond heat spreaders to achieve improved thermal management and therefore lower diode operating temperatures. 2) Development of a practical method of four-way, in-phase power combining within the multiplier housing. 3) The use of active biasing technology to ensure that the diodes are automatically at their optimal bias point even as the source frequency is rapidly tuned across the operating band. Additionally a prototype amplifier-multiplier chain will be delivered to NASA JPL, demonstrating the feasibility of these innovations.