Microwave Frequency Sources and Filters Based on Superconducting Photonic Band Gap Structures

Tristan will study a new class of very high Q superconducting structures based on a Photonic Band Gap (PBG) resonator. These structures are physically very different from superconducting cavities or pattered stripline structures, and have unique properties which may overcome many present limitations instate-of-the-art microwave devices. In conjunction with suitable amplifiers, PBG resonators have a variety of microwave applications, including exceptionally high speed AFC loops, ultra-stable oscillators with low phase noise close to the carrier, and precise frequency standards. Such devices are desirable for improving performance in many applications including radar and state-of-the-art communication systems. In order to achieve the full potential of these devices, we will extend this work to cryogenic systems incorporating superconducting cavities. In Phase I, a cryogenic system which can incorporate both high and low Tc devices will be built. We expect to achieve Q>10E5 at 77K using presently available high Tc thin films and Q>10E8 using low Tc materials. Recent work with room temperature PBG resonators at X band can create a true mono-frequency, narrow band oscillator. Numerical simulations to cover K and V bands and by analyzing possible modulation techniques will be performed.