This Small Business Innovation Research (SBIR) Phase I project will investigate the feasibility of implementing new slow-wave circuits and electron beam confinement innovations for terahertz frequency backward-wave oscillators. A backward wave oscillator emits high- frequency radio waves, tuned by the applied voltage, at frequencies and powers generally higher than available from semiconductor-based devices. The envisioned devices have a compact format, suitable for portable applications, and have the potential to operate as moderate-power terahertz- frequency sources. New circuits and electron guns will be fabricated and evaluated, resulting in the basis for a Phase II prototype design. Successful results would include milliwatt-scale, tunable sources.
The broader impact/commercial potential of this project includes helping to further open the ?terahertz gap? for a range of applications. This gap refers to a frequency range where technologies and applications have only been slowly developing and emerging. A terahertz backward-wave oscillator should enable advancements in high-frequency communications; chemical, biological, and environmental sensing and imaging; as well as medical diagnosis and security markets. As such, in addition to the advancement of terahertz science and technology themselves, these devices could help propel developments in a number of burgeoning scientific and industrial activities.
This Small Business Innovation Research Phase I project investigated the feasibility of implementing new slow-wave circuit and electron beam confinement innovations for terahertz frequency backward-wave oscillators. A backward wave oscillator emits high-frequency radio waves, tuned by the applied voltage, at frequencies and powers generally higher than available from semiconductor-based devices. The envisioned devices have a compact format, suitable for portable applications, and have the potential to operate as moderate-power terahertz-frequency sources. New circuits were fabricated and tested in a vacuum chamber. A Phase II production prototype design was conceived. For this project membrane interdigital line (MIDL) slow-wave circuits in the 200-1000 GHz frequency bands were investigated. These MIDL circuits increase the available power output of backward-wave oscillators in this under served part of the electromagnetic spectrum. This circuits were tested with a magnet free electron gun for use in backward-wave oscillators in the 200-1000 GHz frequency band. The absence of the magnets in this electron gun allows for backward-wave oscillator devices to be more compact and portable. While MIDL circuits and magnet free electron guns were specifically designed for backward-wave oscillators (BWO) in this project, these devices also represent a contribution to travelling-wave tube devices (TWT). These MIDL BWOs and TWTs will contribute better, more powerful sources to fields such as imaging, communications, sensing, diagnostics and treatment.
