High-Frequency Antenna Arrays and Coupling Structures Project

We are fabricating antenna arrays and coupling structure for frequencies in the 200-300 GHz frequency bands. The primary motivation of this work is to develop antenna coupling for superconducting ultra-compact spectrometer on a chip at millimeter- and submillimeter-wave bands. One of the key requirements for these spectrometers, which will have hundreds of pixels, is to have antenna arrays with high coupling efficiency, low reflections, and good Gaussian beam patterns. An ultra-compact superconducting on-chip-spectrometer has the potential to revolutionize far-IR through millimeter-wave observational astronomy and astrophysics, allowing for the first time wide-field mm- and sub-mm spectral surveys and efficient follow up observations of known sources. Our ultimate plan is to use planar lithography to fabricate superconductin g transmission line filters to sort incident radiation by frequency to an array of direct detectors such as MKIDs. However, for this task, we are only focusing on the antenna array element and coupling structures which will couple energy from the telescope to the spectrometer chip. We will design and fabricate a 2x2 array of multi-flare-angle smooth walled horn array to demonstrate the feasibility of this concept for the spectrometer-on-a-chip as well as other focal plane arrays in the submillimeter-wave frequency band. The 2x2 horn array antennas will be fabricated using a tool which can make hundreds of arrays of horn antennas without much difficulty. This is the key innovation of this approach. The horn array will be designed for the 190-320 GHz frequency band. We will also design and fabricate a 2x2 array of circular to rectangular transition block which will be used to test the performance of the horn array. Fig. 1 shows the design concept and that fabrication tool that will enable fabrication of antenna arrays with hundreds of pixels. More »