Description: 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.

Benefits: Heterodyne receivers have been demonstrated to frequencies as high a 4.7THz. These are generally used for radio astronomy from airborne or space platforms. A specific requirement for these systems is the local oscillator sources used to pump the frequency mixer. A present goal is the development of array receivers, which greatly increase the data collecting capabilities of observatories, but also require more power than can be generated with present solid-state sources. The development of higher power sources in the frequency range around 300GHz is a critical step that is required to enable the development of array receivers for astronomy in the terahertz band.

Non-NASA commercial applications include the NMR-DNP and EPR measurements for chemistry and high power sources for reflectometry measurements for plasma diagnostic systems for nuclear fusion experiments. More commercially, higher power solid-state sources can be used in imaging systems; for portal security, collision avoidance radars, fire-fighting, and industrial process control and monitoring. Higher power sources in this frequency band are a critical step in achieving a technology that will allow the full use of the terahertz frequency range for scientific, defense, security and industrial applications.