Microwave kinetic inductance detectors (MKIDs) represent a class of low-temperature superconducting detectors employed for observing astronomical phenomena spanning the submillimeter through visible bands. Renowned for their intrinsic frequency-division multiplexing capability at microwave frequencies, MKIDs offer the advantage of eliminating the need for complex cryogenic multiplexing electronics. However, the overall readout architecture remains complex, necessitating sophisticated room-temperature electronics. Optimizing overall performance poses a significant challenge. This article introduces a novel approach to behavioral modeling and simulation for the MKID readout system utilizing Simulink and the RF Blockset library. The models incorporate major nonidealities of electronic components to investigate their impacts on system performance. In addition, the model of the MKID array is included based on measured transmission data, ensuring high simulation accuracy. The simulation tool facilitates the study and high-level design of the MKID readout system before delving into hardware implementation.
Microwave kinetic inductance detectors (MKIDs) represent a class of low-temperature superconducting detectors employed for observing astronomical phenomena spanning the submillimeter through visible bands. Renowned for their intrinsic frequency-division multiplexing capability at microwave frequencies, MKIDs offer the advantage of eliminating the need for complex cryogenic multiplexing electronics. However, the overall readout architecture remains complex, necessitating sophisticated room-temperature electronics. Optimizing overall performance poses a significant challenge. This article introduces a novel approach to behavioral modeling and simulation for the MKID readout system utilizing Simulink and the RF Blockset library. The models incorporate major nonidealities of electronic components to investigate their impacts on system performance. In addition, the model of the MKID array is included based on measured transmission data, ensuring high simulation accuracy. The simulation tool facilitates the study and high-level design of the MKID readout system before delving into hardware implementation.
A microwave kinetic inductance detector (MKID) is a superconducting pair-breaking detector used for astronomical observations in the sub-millimeter through visible range. Radiation is detected as a phase and amplitude signal proportional to the frequency shift of the device. In the case of arrays of MKIDs, the read-out is performed using the frequency division multiplexing technique. However, there is currently no commercial system or low-cost standard electronics available for this task. In this work, we take the first steps towards developing a low-cost readout system for MKIDs based on the Red Pitaya board. We have developed a firmware for the efficient generation of probe tones, and show figures of merit characterizing the performance of the readout in a hardware prototype. The design is flexible, letting us to adapt it to new frequencies and amplitudes requirements of the MKID arrays.
This report covers work done at Data Processing and Readout System Development Laboratory at Nazarbayev University implementing data processing algorithm for readout electronics. Microwave Kinetic Inductance Detectors (MKIDs) are photon detectors based on superconducting resonators. MKIDs are capable of detecting single photons with very small energy and micro second time resolutions. With proper readout electronic system it is possible to read arrays of thousands MKIDs using single signal line using frequency domain multiplexing (FDM). This report details the work done developing a laboratory setup for measuring MKIDs and developing code for frequency measurements. All the work was done using readout system based on a Re-configurable Open Archite Computing Hardware (ROACH) FPGA board and The Collaboration for Astronomy Signal Processing and Electronics Research (CASPER) software.
Microwave Kinetic Inductance Detectors (MKIDs) have great potential for large very sensitive detector arrays for use in, for example, sub-mm imaging. Being intrinsically readout in the frequency domain, they are particularly suited for frequency domain multiplexing allowing $\sim$1000s of devices to be readout with one pair of coaxial cables. However, this moves the complexity of the detector from the cryogenics to the warm electronics. We present here the concept and experimental demonstration of the use of Fast Fourier Transform Spectrometer (FFTS) readout, showing no deterioration of the noise performance compared to low noise analog mixing while allowing high multiplexing ratios.
The frequency comb generator is an essential component in the readout of superconducting detectors. This component is responsible for generating the resonant frequencies necessary to detect photon interaction with the detectors. This component however has not received the much needed attention in terms of readout systems optimization. Conventional implementations rely on either inverse fast Fourier transform (IFFT) engines, which scale poorly in power with increasing frequency resolution requirement but allow flexible tone updates, or lookup tables (LUTs), which demand large memory for high frequency resolution. Microwave Kinetic Inductance Detectors (MKIDs) are superconducting detectors which have gained significant interest for cryogenic astrophysical instrumentation due to their high sensitivity, intrinsic multiplexing capability, and scalable fabrication. However, their simplified detector architecture shifts complexity to the readout electronics, making the development of compact, low-power frequency comb generators especially valuable. The design of the compact frequency comb generator targets applications involving MKIDs which typically detect photons in the submilliter bands. In this thesis, I present the design and hardware realization of a compact frequency comb generator. The design has been verified on an Field Programmable Gate Array (FPGA) using the Xilinx's RFSoC ZCU111 evaluation board. The architecture consumes less than 5% of FPGA resources and less than 5 Watts of power with the capability of handling multiple independent channels of the compact frequency comb generator on the evaluation board. These results demonstrate the potential of this approach to enable scalable, energy-efficient MKID readout systems for large-format detector arrays in next-generation cryogenic experiments.
Microwave kinetic inductance detectors have great potential for large, very sensitive detector arrays for use in, for example, submillimeter imaging. Being intrinsically readout in the frequency domain, they are particularly suited for frequency domain multiplexing allowing ∼1000 s of devices to be readout with one pair of coaxial cables. However, this moves the complexity of the detector from the cryogenics to the warm electronics. We present here the concept and experimental demonstration of the use of fast Fourier transform spectrometer readout, showing no deterioration of the noise performance compared to the low noise analog mixing while allowing high multiplexing ratios.
Microwave Kinetic Inductance Detectors (MKIDs) are extremely sensitive radiation detectors based on superconducting resonators that can be combined in large arrays on a single readout line within a limited frequency bandwidth. This makes MKIDs ideal detectors for the ultimate far-infrared observatory: a future space-based actively cooled telescope with its performance solely limited by the low universe background radiation. However, to reach these detector requirements, state-of-the-art MKIDs still need a order of magnitude improvement in device sensitivity. In this work, the MKID sensitivity is improved by reducing the aluminium volume that absorbs pair-breaking radiation into quasiparticle excitations, while making sure all radiation is still absorbed. Furthermore, a key requirement is sufficient reduction of excess noise as to keep the device intrinsically limited by thermally driven random fluctuations in the number of quasiparticles in absence of radiation, or Generation-Recombination (G-R) noise. To this end, a model is developed that describes the noise contributions as function of device geometry, readout power, material properties and radiation power. Subsequently, a realistic MKID design is presented and tested that reduces excess noise and maximises the sensitivity, expressed as Noise Equivalent Power (NEP). At high temperatures, good overall agreement is found between the measured noise spectra and the model. At low temperature T = 120 mK, the measurement results give an optical NEP similar to current state-of-the-art MKIDs. The NEP is not as low as expected due to short quasiparticle lifetimes, an unexpected decrease in the G-R noise level and a very high excess noise attributed to Two-Level Systems (TLS) noise that starts to dominate the already low G-R noise spectrum at low temperatures. Possibly, the quick quasiparticle lifetime saturation and noise level drop are caused by a strong readout power effect, as the readout power is known to create excess quasiparticles and to cause a strongly non-thermal electron energy distribution in the aluminium strip of the MKID. However, the exact microscopic details of these effects are unknown and not studied in this project. Based on the current chip design, a straightforward way to improve device performance and study the readout power effect in more detail is a reduction of the high TLS noise levels, which is possibly fabrication related. This would allow an unobstructed view of the G-R noise spectrum at low temperatures, thereby allowing both a study of the readout power effect on the quasiparticle system, and ultimately achieving the improvement in NEP needed reach the detector requirements for the ultimate space-based far-infrared observatory.