Kongpop U-yen

• PhD
• Rombhodidham International Temple

We describe a testbed to characterize the optical response of compact superconducting on-chip spectrometers in development for the EXperiment for Cryogenic Large-Aperture Intensity Mapping (EXCLAIM) mission. EXCLAIM is a balloon-borne far-infrared experiment to probe the CO and CII emission lines in galaxies from redshift 3.5 to the present. The sp...

In recent years, the recovery of gold from electronic waste, especially waste printed circuit boards (PCBs), has grown in importance. PCBs consist of organic epoxy resins overlaid with valuable metals. The first step in recovering metals from waste PCBs is the removal of these resins. In this paper, autoclave-assisted alkaline pretreatment employin...

This paper describes a cryogenic optical testbed developed to characterize u-Spec spectrometers in a dedicated dilution refrigerator (DR) system. u-Spec is a far-infrared integrated spectrometer that is an analog to a Rowland-type grating spectrometer. It employs a single-crystal silicon substrate with niobium microstrip lines and aluminum kinetic...

In this paper, the influence of magnetic fields on the ultraviolet (UV) absorption of water circulated within three different magnetic configurations (inside, outside, and dual Halbach array magnetizers) is presented. Permanent magnets were inserted in the designed magnetizer and magnetic flux densities were varied between 380 and 580 mT. The sampl...

The feasibility of hydrometallurgy for metal extraction from electronic wastes was investigated in the current work. Samples were ground and preliminary extracted by nitric acid and aqua regia. The gold concentrations in nitric acid and aqua regia were measured as 1.82 mg·L¹ and 29.45 mg·L¹, respectively. In addition, extraction performances using...

A study investigating the physical properties and use of the SiAl composite Controlled Expansion 7 (CE7) for the packaging of silicon bolometric detectors for millimeter-wave astrophysical applications at cryogenic temperatures is presented. The existing interfaces to such detectors are typically made of either ductile metals or micro-machined sili...

The influence of the magnetic generator device on both the quality and quantity of lettuce (Lactuca sativa L.) grown by a circulating hydroponic method was investigated. The device was developed based on the engineering design process and subjected to simulation-based computational software. Tap water and nutrient solution flowed through magnetic f...

This paper studied the different CaCO3 crystal forms between calcite and aragonite under magnetic fields using calcocarbonic solution prepared from dissolving ground natural shell. The experiments were conducted by exposing the solution to magnetic fields. The characteristics of reprecipitated CaCO3 were investigated. The aragonite/calcite ratios w...

In this work, metals were recovered from electronic wastes under optimized conditions. The columnar extraction was used to increase the contact between the leachate solution and solid-state wastes. Industrial metals were recovered by an electrochemical process using a regenerated mild oxidizer under optimized operating parameters to enrich the meta...

Methylene blue dye can induce negative effects to aquatic life and the environmental system. So, it is important to remove it from water. Although, the photocatalytic degradation of dye solution during magnetic treatment (or static water process) can increase the dye degradation, but it cannot apply for a large wastewater. Therefore, the dynamic fl...

In the present study, precipitation method was used to synthesize three Mn-doped minerals, namely, dittmarite, struvite, and newberyite, and LiMg0.74Mn0.26PO4 phosphor was prepared through thermal synthesis using each of the afore-mentioned minerals as a precursor. Slight changes in the X-ray diffraction positions in the Mn-dopants validated that t...

Plate-like hureaulite is successfully synthesized via a simple precipitation technique, and its vibrational and thermal behaviors are investigated. Its composition stabilizes at up to 165 °C and decomposes to Mn2P2O7 and Mn3(PO4)2 with different morphologies. Three thermal processes correspond to the first and second dehydrations, and polycondensat...

This paper investigates the influence of magnetic fields on the properties of water in both static and dynamic magnetizations by tracking the changes in infrared absorption, Raman scattering, heat capacity and salt solubility. The results indicate the changes in electron distribution, molecular dipole moment and molecular polarization of magnetized...

Magnesium pyrophosphate catalysts synthesized via the thermal decomposition of dittmarite, struvite, and newberyite precursors were applied for biodiesel production by transesterification. Physicochemical properties of the catalysts and effects of operating transesterification conditions on the biodiesel yield were investigated. Analytical data rev...

This research studies the influence of static magnetic fields on the structure of calcium carbonate (CaCO3) crystals. Experiments were conducted by exposing Ca2+ and CO32− solutions to magnetic fields. The solutions were then combined to form CaCO3 particles. Three characteristics of CaCO3 formation reaction have been investigated, namely absorbanc...

We report on the development of a polarization-sensitive dichroic (150/220 GHz) detector array for the Cosmology Large Angular Scale Surveyor (CLASS) delivered to the telescope site in June 2019. In concert with existing 40 and 90 GHz telescopes, the 150/220 GHz telescope will make observations of the cosmic microwave background over large angular...

We report on the development of a polarization-sensitive dichroic (150/220 GHz) detector array for the Cosmology Large Angular Scale Surveyor (CLASS) delivered to the telescope site in June 2019. In concert with existing 40 and 90 GHz telescopes, the 150/220 GHz telescope will make observations of the cosmic microwave background over large angular...

Micro-Spec (µ-Spec) is a direct-detection spectrometer which integrates all the components of a diffraction-grating spectrometer onto a ~ 10-cm^2 chip through the use of superconducting microstrip transmission lines on a single-crystal silicon substrate. A second-generation µ-Spec is being designed to operate with a spectral resolution of 512 in th...

The design of a two-dimensional spatial beam-combining network employing a parallel-plate superconducting waveguide filled with a monocrystalline silicon dielectric substrate is presented. This component uses arrays of magnetically coupled antenna elements to achieve high coupling efficiency and full sampling of the intensity distribution while avo...

The Cosmology Large Angular Scale Surveyor (CLASS) aims to detect and characterize the primordial B-mode signal and make a sample-variance-limited measurement of the optical depth to reionization. CLASS is a ground-based, multi-frequency microwave polarimeter that surveys 70% of the microwave sky every day from the Atacama Desert. The focal plane d...

The Cosmology Large Angular Scale Surveyor (CLASS) aims to detect and characterize the primordial B-mode signal and make a sample-variance-limited measurement of the optical depth to reionization. CLASS is a ground-based, multi-frequency microwave polarimeter that surveys 70% of the microwave sky every day from the Atacama Desert. The focal plane d...

We present here a study of the use of the SiAl alloy CE7 for the packaging of silicon devices at cryogenic temperatures. We report on the development of baseplates and feedhorn arrays for millimeter wave bolometric detectors for astrophysics. Existing interfaces to such detectors are typically made either of metals, which are easy to machine but mi...

Strategies are explored to reduce the electromag- netic simulation time of electrically large superconducting trans- mission line structures while retaining model accuracy. The complex surface reactance of an infinite thin-film superconducting sheet is evaluated with the BCS (Bardeen-Cooper-Schrieffer) theory and used as an input to model the phase...

A waveguide split-block fixture used in the characterization of thin-film superconducting planar circuitry at millimeter wavelengths is described in detail. The test fixture is realized from a pair of mode converters, which transition from rectangular-waveguide to on-chip microstrip-line signal propagation via a stepped ridge-guide impedance transf...

The design and fabrication of low-loss wide-bandwidth superconducting vacuum-gap crossovers for high performance millimeter wave applications are described. In order to reduce ohmic and parasitic losses at millimeter wavelengths a vacuum gap is preferred relative to dielectric spacer. Here, vacuum-gap crossovers were realized by using a sacrificial...

The design and fabrication of low-loss wide-bandwidth superconducting vacuum-gap crossovers for high performance millimeter wave applications are described. In order to reduce ohmic and parasitic losses at millimeter wavelengths a vacuum gap is preferred relative to dielectric spacer. Here, vacuum-gap crossovers were realized by using a sacrificial...

We describe feedhorn-coupled polarization-sensitive detector arrays that utilize monocrystalline silicon as the dielectric substrate material. Monocrystalline silicon has a low-loss tangent and repeatable dielectric constant, characteristics that are critical for realizing efficient and uniform superconducting microwave circuits. An additional adva...

The Cosmology Large Angular Scale Surveyor (CLASS) will measure the polarization of the Cosmic Microwave Background to search for and characterize the polarized signature of inflation. CLASS will operate from the Atacama Desert and observe $\sim$70% of the sky. A variable-delay polarization modulator (VPM) modulates the polarization at $\sim$10 Hz...

Characterization of the minute cosmic microwave background polarization signature requires multi-frequency, high-throughput precision instrument systems. We have previously described the detector fabrication of a 40 GHz focal plane and now describe the fabrication of detector modules for measurement of the CMB at 90 GHz. The 90 GHz detectors are a...

We describe feedhorn-coupled polarization-sensitive detector arrays that utilize monocrystalline silicon as the dielectric substrate material. Monocrystalline silicon has a low-loss tangent and repeatable dielectric constant, characteristics that are critical for realizing efficient and uniform superconducting microwave circuits. An additional adva...

μ-Spec is a compact submillimeter (~ 100 GHz - 1:1 THz) spectrometer which uses low loss superconducting microstrip transmission lines and a single-crystal silicon dielectric to integrate all of the components of a diffraction grating spectrometer onto a single chip. We have already successfully evaluated the performance of a prototype μ-Spec, with...

Superconducting microwave resonators are of interest for a wide range of applications, including for their use as microwave kinetic inductance detectors (MKIDs) for the detection of faint astrophysical signatures, as well as for quantum computing applications and materials characterization. In this paper, procedures are presented for the fabricatio...

Micro-Spec (µ-Spec) is a direct-detection spectrometer-on-a-chip realized with superconducting microstrip transmission lines. Its operating spectral range is 300–650 GHz (450–1000 µm), a window of interest for many far-infrared and submil-limeter spectroscopic applications in astronomy and Earth science. Due to its compact size (≈ 10 cm 2), µ-Spec...

A method is proposed and experimentally explored for in-situ calibration of complex transmission data for superconducting microwave resonators. This cryogenic calibration method accounts for the instrumental transmission response between the vector network analyzer reference plane and the device calibration plane. Once calibrated, the observed reso...

The Cosmology Large Angular Scale Surveyor (CLASS) is an experiment to measure the signature of a gravita-tional-wave background from inflation in the polarization of the cosmic microwave background (CMB). CLASS is a multi-frequency array of four telescopes operating from a high-altitude site in the Atacama Desert in Chile. CLASS will survey 70\% o...

We report on the status and development of polarization-sensitive detectors for millimeter-wave applications. The detectors are fabricated on single-crystal silicon, which functions as a low-loss dielectric substrate for the microwave circuitry as well as the supporting membrane for the Transition-Edge Sensor (TES) bolometers. The orthomode transdu...

The Cosmology Large Angular Scale Surveyor (CLASS) experiment aims to map the polarization of the Cosmic Microwave Background (CMB) at angular scales larger than a few degrees. Operating from Cerro Toco in the Atacama Desert of Chile, it will observe over 65% of the sky at 38, 93, 148, and 217 GHz. In this paper we discuss the design, construction,...

A waveguide structure for a dual polarization waveguide includes a first flange member, a second flange member, and a waveguide member disposed in each of the first flange member and second flange member. The first flange member and the second flange member are configured to be coupled together in a spaced-apart relationship separated by a gap. The...

We describe the instrument architecture of the CLASS instrument, a ground-based cosmic microwave background (CMB) polarimeter that will measure the large-scale polarization of the CMB in several frequency bands to search for evidence of inflation.

We have designed, fabricated and characterized absorptive thermal blocking filters for cryogenic microwave applications. The transmission line filter's input characteristic impedance is designed to match $50\,\Omega$ and its response has been validated from 0-to-50\,GHz. The observed return loss in the 0-to-20\,GHz design band is greater than $20\,...

We have designed, produced, and tested 40 GHz feedhorn-coupled transition-edge sensor (TES) detectors using microstrip circuits on monocrystalline silicon dielectric substrates. Symmetric planar orthomode transducers (OMTs) couple two independent orthogonal linear polarization modes from feedhorns onto planar transmission lines over a broad (60 %)...

Optimal performance of background limited thermal detectors requires adequate control over all relevant sources of incident electromagnetic radiation. In addition to the radiant power incident from the scene of interest, undesired or spurious power can potentially couple to the sensor via its bias and readout circuitry employed to operate the devic...

The Cosmology Large Angular Scale Surveyor (CLASS) is a ground-based instrument that will measure the polarization of the cosmic microwave background to search for evidence for gravitational waves from a posited epoch of inflation early in the Universe's history. This measurement will require integration of superconducting transition-edge sensors w...

Microspec is a new class of submillimeter and millimeter (250-700 μm wavelength) spectrometer, in which the wavelength separation and detection of incident light is done on a single substrate. The instrument is designed for space exploration by offering high spectral resolving power over a broad band, while being orders of magnitude smaller in mass...

We explore a free-space polarization modulator in which a variable phase is introduced between the right- and left-handed circular polarization components and used to rotate the linear polarization of the outgoing beam relative to that of the incoming beam. In this device, the polarization states are separated by a circular polarizer that consists...

We report technology development of millimeter/submillimeter polarization modulators that operate by introducing a variable, controlled phase delay between two orthogonal polarization states. The variable-delay polarization modulator (VPM) operates via the introduction of a variable phase delay between two linear orthogonal polarization states, res...

Observations of the cosmic microwave background (CMB) provide a powerful tool for probing the evolution of the early universe. Specifically, precision measurement of the polarization of the CMB enables a direct test for cosmic inflation. A key technological element on the path to the measurement of this faint signal is the capability to produce lar...

Recent measurements of micron-sized Mo/Au bilayer TESs have demonstrated that the TES can behave like an S-S′-S weak link due to the lateral proximity effect from superconducting leads. In this regime the T c is a function of bias current, and the effective T c shifts from the bilayer T c towards the lead T c . We explore the idea that a micron-siz...

Future ground and space-based astronomy missions in the millimeter and sub-millimeter range will rely upon kilopixel detector arrays. We are developing a superconducting Transition-Edge Hot-Electron Bolometer (THM) for use in these next generation missions. Thermal isolation of the THM is controlled by the hot-electron effect between the electrons...

We have successfully fabricated a superconducting transition edge sensor (TES), bolometer that centers on the use of electron-phonon decoupling (EPD) for thermal isolation. We have selected a design approach that separates the two functions of far-infrared and THz radiative power absorption and temperature measurement, allowing separate optimizatio...

The next generation of Cosmic Microwave Background (CMB) experiments probing for signals of inflation and small angular scale polarization anisotropies require higher sensitivity and better control of systematics. We are developing monolithic arrays of orthomode transducer (OMT) coupled transition edge sensor (TES) polarimeters designed for operati...

We have fabricated absorber-coupled microwave kinetic inductance detector (MKID) arrays for sub-millimeter and farinfrared astronomy. Each detector array is comprised of lambda/2 stepped impedance resonators, a 1.5mum thick silicon membrane, and 380mum thick silicon walls. The resonators consist of parallel plate aluminum transmission lines coupled...

Photonic choke joint (PCJ) structures for dual-polarization waveguides have been investigated for use in device and component packaging. This interface enables the realization of a high performance non-contacting waveguide joint without degrading the in-band signal propagation properties. The choke properties of two tiling approaches, symmetric squ...

form only given: Two photonic choke joint (PCJ) structures for dual-polarization waveguides have been investigated. Structures with Cartesian and Archimedean tiling were implemented to provide a low-loss non-contacting surface at a waveguide interface while preserving the signal polarizations. The optimal dimensions for each tiling configuration ha...

We discuss materials characterization and integration considerations for large‐format, antenna‐coupled, low‐noise, cryogenic, bolometer arrays for far‐infrared space‐based observatories. The suitability of Bi as an antenna termination resistor and annealed gold for microstrip and groundplane, in the context of using each to optimize signal and band...

We describe the development of a detector for precise measurements of the cosmic microwave background polarization. The detector employs a waveguide to couple light between a pair of Mo/Au superconducting transition edge sensors (TES) and a feedhorn. Incorporation of an on‐chip ortho‐mode transducer (OMT) results in high isolation. The OMT is micr...

We present simulations and discuss measurements of a planar orthomode transducer (OMT) being developed for use with bolometric detectors in observations of the polarization of the cosmic microwave background (CMB). This OMT couples radiation from a circular waveguide onto microstrip where it is filtered and then detected. A corrugated feed horn def...

The next generation of cosmic microwave background (CMB) polarization experiments targeting the signatures of inflation will require unprecedented sensitivities in addition to careful control of systematics. With existing detector technologies approaching the photon noise limit, improvements in system sensitivities must come from ever-larger focal...

This paper presents the design of a microstrip-CPW transition where the CPW line propagates close to slotline mode. This design allows the solution to be determined entirely though analytical techniques. In addition, a planar via-less microwave crossover using this technique is proposed. The experimental results at 5 GHz show that the crossover has...

We are developing a Transition-edge Hot-electron Microbolometer (THM) with the capacity to make sensitive and broadband astrophysical observations over frequencies ranging from 30-300 GHz (10-1 mm). This micron-sized bolometer consists of a superconducting bilayer Transition-Edge Sensor (TES) and a thin-film absorber. The THM employs the decoupling...

We describe measurements of the properties, at dc, gigahertz, and terahertz frequencies, of thin (10 nm) aluminum films with 10 Omega/square normal state sheet resistance. Such films can be applied to construct microwave kinetic inductance detector arrays for submillimeter and far-infrared astronomical applications in which incident power excites q...

During 2015, a unique launch opportunity exists that allows for a New-Frontiers-class mission to discover a compositional gradient of small bodies in our solar system. The proposed seven year mission includes a flyby of main belt asteroid (108144) 2001 HM1, a flyby and impactor release (a la Deep Impact) at the Trojan asteroid (624) Hektor (a suspe...

We are developing a Transition-Edge Hot-electron Microbolometer (THM) for use in large detector array applications in millimeter-wave astronomy. This bolometer detector consists of a superconducting bilayer TES with an overlapping thin-film semi-metal absorber. The detector is deposited directly on the substrate and thermal isolation of the bolomet...

This paper proposes a technique to design a compact planar broadband microwave blocking filter. The filter is constructed from multiple sections of bandstop filters with means to control radiation loss. As a result, the filter has small physical size and provides multi-decade of suppression frequency bandwidth. The total length is less than half-wa...

Characterization of the cosmic microwave background polarization will ultimately require both a large number of cooled background limited detector elements and precise control of instrument systematics. To this end, bolometric sensors with passive circuit elements integrated on a chip form an attractive technology owing in part to the technological...

We present preliminary design and development work on polarized detectors intended to enable Cosmic Microwave Background polarization measurements that will probe the first moments of the universe. The ultimate measurement will be challenging, requiring background-limited detectors and good control of systematic errors. A large collection of single...

We describe a prototype detector system designed for precise measurements of Cosmic Microwave Background polarization. The design combines a quasi-optical polarization modulator, a metal feedhorn, a superconducting planar microwave circuit, and a pair of transition-edge sensor (TES) bolometers operating at <100 mK. The circular feedhorn produces hi...

The improved version of a broadband planar magic-T using microstrip-slotline transitions is presented. The design implements a small microstrip-slotline tee junction with minimum size slotline terminations to reduce radiation loss. A multisection impedance transformation network is used to increase the operating bandwidth and minimize the parasitic...

The design of a compact low-loss magic-T is proposed. The planar magic-T incorporates the compact microstrip-slotline tee junction and small microstrip-slotline transition area to reduce slotline radiation. The experimental results show that the magic-T produces broadband in-phase and out-of-phase power combiner/divider responses, has an average in...

We propose a low-loss slotline (SL) stepped circular ring termination for use in a microstrip-to-slotline (MS-to-SL) transition. Not only does this termination achieve broadband characteristics, but it also reduces SL radiation. The experimental results show that, using the proposed technique, the radiation loss around the pass-band frequency is lo...

The primordial anisotropy polarization pathfinder array (PAPPA) is a balloon-based instrument to measure the polarization of the cosmic microwave background and search for the signal from gravity waves excited during an inflationary epoch in the early universe. PAPPA will survey a 20° × 20° patch at the North Celestial Pole using 32 pixels in 3 pas...

The Primordial Anisotropy Polarization Pathfinder Array (PAPPA) is a balloon-based instrument to measure the polarization of the cosmic microwave background and search for the signal from gravity waves excited during an inflationary epoch in the early universe. PAPPA will survey a 20 x 20 deg patch at the North Celestial Pole using 32 pixels in 3 p...

We propose a new type of microstrip half-wavelength (lambda/2) stepped impedance resonator (SIR) for use in bandpass filter (BPF) designs. This lambda/2 SIR has an internal coupling section that can be used to generate a coupling coefficient in the filter design in addition to couplings between SIRs. It also contains additional stepped impedance li...

PAPPA is a balloon-based experiment designed to measure the polarization of the Cosmic Microwave Background using candidate technology for an eventual Einstein Inflation Probe mission. It will survey a 20° × 20° patch of sky with 0.5° angular resolution covering 3 passbands centered at 89, 212 and 302 GHz. Detection will be accomplished via antenna...

In this paper, we propose a compact planar bandpass filter design with wide stopband. The double split-end quarter-wave-length (λ/4) resonator is introduced to reduce the resonator size while providing additional transmission zeros. Optimal split-end length is determined to provide transmission zeros that attenuate the two lowest spurious resonance...

This dissertation contains two significant investigations. One is the development of the broadband microwave bandpass filters with high out-of-band performance. The other is the development of low-loss hybrids. These researches are parts of the National Aeronautic and Space Administrator (NASA)s mission to explore the universe. The former is focuse...

We propose an analytical design for a microstrip broadband spurious-suppression filter. The proposed design uses each section of the transmission line as both a coupling and a spurious suppression element. Every two sections of the transmission line are combined to create a quarter-wavelength stepped impedance resonator (λ/4 SIR). The optimal reson...

We propose an ultra compact single-layer spurious suppression band pass filter design which has the following benefit: 1) Effective coupling area can be increased with no fabrication limitation and no effect on the spurious response; 2) Two fundamental poles are introduced to suppress spurs; 3) Filter can be designed with up to 30% bandwidth; 4) Th...

The paper analyzes the effect of finite microwave switch isolation on the beam pattern generated by an N×N Butler matrix beamforming network. The result indicates that, as switch isolation becomes lower, the array's sidelobe levels increase, and the angle in the main beam shifts slightly. The sidelobe level increases in proportion to the level of i...

This paper presents a CDMA power amplifier using Kahn envelope elimination and restoration technique. A CMOS delta-modulated envelope amplifier with over 3MHz bandwidth is used as the dynamic power supply. Internal feedback was used on the envelope amplifier to reduce delay. A commercially available 1W GaAs/AlGaAs HFET power amplifier was tested in...

A new technique for optimizing the design of low-loss bidirectional (n,m) microwave switch matrices is proposed for use in smart antenna systems. Based on Banyan networks as a base-line topology, architecture trade offs are made between routing complexity, component count, reliability, isolation, and insertion loss. It applies to any number of inpu...

An approach to the optimum design of a large-scale blocking switch matrix has been developed. The approach minimizes insertion loss of any n×m switch matrix by deriving optimum configurations for all cascading states. Each state consists of either switches or junctions. To demonstrate an accuracy of the technique, we have designed an 8×2 switch mat...

This paper proposes a wideband adaptive predistortion linearization system based on high-speed RF envelope modulation applied to the input signal of an RF power amplifier. An FPGA-based look-up table, fed by a digitized envelope power signal, controls the envelope modulation performed by an RF vector modulator. The advantages of this predistortion...

This paper reports on the design and implementation of a process, temperature and supply compensated 7-MHz clock oscillator in a 0.25 μm, double poly, 5-metal CMOS process. The clock generator is based on a 3-stage differential ring oscillator. The compensation technique incorporates a unique combination of a process corner sensing scheme and a tem...

This paper presents a mixed-signal behavioral simulation for an RF power amplifier predistortion system. The predistortion architecture is based on FPGA-based look-up tables that drive RF vector modulators. Behavioral models are extracted from the RF components and simulated in the same file with the digital components. Trade-offs are made between...