Discrete-Time Mixing Receiver Architecture for RF-Sampling Software-Defined Radio

A discrete-time (DT) mixing architecture for RF-sampling receivers is presented. This architecture makes RF sampling more suitable for software-defined radio (SDR) as it achieves wideband quadrature demodulation and wideband harmonic rejection. The paper consists of two parts. In the first part, different downconversion techniques are classified and compared, leading to the definition of a DT mixing concept. The suitability of CT-mixing and RF-sampling receivers to SDR is also discussed. In the second part, we elaborate the DT-mixing architecture, which can be realized by de-multiplexing. Simulation shows a wideband 90° phase shift between I and Q outputs without systematic channel bandwidth limitation. Oversampling and harmonic rejection relaxes RF pre-filtering and reduces noise and interference folding. A proof-of-concept DT-mixing downconverter has been built in 65 nm CMOS, for 0.2 to 0.9 GHz RF band employing 8-times oversampling. It can reject 2nd to 6th harmonics by 40 dB typically and without systematic channel bandwidth limitation. Without an LNA, it achieves a gain of -0.5 to 2.5 dB, a DSB noise figure of 18 to 20 dB, an IIP3 = +10 dBm, and an IIP2 = +53 dBm, while consuming less than 19 mW including multiphase clock generation

A Low Noise Sub-Sampling PLL in Which Divider Noise Is Eliminated and PD-CP Noise Is not multiplied by N^2

This paper presents a 2.2-GHz low jitter sub-sampling based PLL. It uses a phase-detector/charge-pump (PD/CP)that sub-samples the VCO output with the reference clock. In contrast to what happens in a classical PLL, the PD/CP noise is not multiplied by N2 in this sub-sampling PLL, resulting in a low noise contribution from the PD/CP. Moreover, no frequency divider is needed in the locked state and hence divider noise and power can be eliminated. An added frequency locked loop guarantees correct frequency locking without degenerating jitter performance when in lock. The PLL is implemented in a standard 0.18- m CMOS process. It consumes 4.2 mA from a 1.8 V supply and occupies an active area of 0.4 X 0.45 m

Microprocessor control of converters for direct current transmission

Imperial Users onl

Comparison of Design Approaches for Low-Cost Sampling Mechanisms in Open-Source Chemical Instrumentation

Robotic positioning systems are used in a variety of chemical instruments, primarily for liquid handling purposes, such as autosamplers from vials or well plates. Here, two approaches to the design of open-source autosampler positioning systems for use with 96-well plates are described and compared. The first system, a 3-axis design similar to many low-cost 3D printers that are available on the market, is constructed using an aluminum frame and stepper motors. The other system relies upon a series of 3D printed parts to achieve movement with a series of linker arms based on Selective Compliance Assembly Robot Arm (SCARA) design principles. Full printer design files, assembly instructions, software, and user directions are included for both samplers. The positioning precision of the 3-axis system is better than the SCARA mechanism due to finer motor control, albeit with a slightly higher cost of materials. Based on the improved precision of this approach, the 3-axis autosampler system was used to demonstrate the generation of a segmented flow droplet stream from adjacent wells within a 96-well plate

High-Q Millimeter Wave RF Filters and Multiplexers

For a long period of time, millimeter waves (mm-Wave) were considered unsuitable for wireless data transmission due to high attention while propagating in the atmosphere. Over the past few years, due to the vigorous developments of multiple-in-multiple-out (MIMO) antenna technology and semiconductor technology, it is now feasible to have reliable wireless data transmissions using mm-Wave. Traditionally, mobile communication networks operate in the frequency spectrum under 6 GHz. In order to meet the ever-increasing demand for high communication data rate and high-quality multi-media services, the current fifth generation (5G) and the emerging 6G mobile communication systems will start to utilize the mm-Wave spectrum due to its bandwidth advantages, which in turn translates into a high data transmission rate. Millimeter-wave technology is also widely used in radar, imaging, medical therapy, and sensing applications. For those reasons, over the past few years, the interest in mm-Wave spectrum has significantly increased. RF filters are essential components in any communication systems to provide frequency selectivity. As the operating frequency of communication systems is extending to the mm-Wave spectrum, the conductor loss, the dielectric loss, and the radiation loss increase rapidly, which makes it challenging to develop high-Q mm-Wave filters. Three-dimensional (3D) waveguide filter structures exhibit excellent RF performance at mm-Wave frequencies and have been widely employed in high-performance RF systems. Nevertheless, as the operating frequency increases to mm-Wave frequency, the physical sizes of the waveguide filters become miniature in size impeding the use of post-fabricated tuning elements to compensate for the manufacturing tolerances of the traditional machining technologies. The silicon-micromachining technology has the potential to develop very accurate miniature 3D filters. This thesis focuses on the development of high-Q ultra-wideband mm-Wave planar filters using multilayer superconductor technology and 3D filter structures using silicon micromachining technology, making use of recent advances in deep reactive ions etching (DRIE) techniques. This thesis first introduces a new technique for filter design and tuning using the phase of the input impedance (PII) as the design parameter. This novel method is applicable to both narrow and wideband filters. Compared with conventional filter design and tuning methods, this approach requires less computation time and provides a clear step-by-step procedure for identifying the proper inter-resonator coupling and the resonant frequencies of the resonators. In practice, the physical realization of the filter always has a non-ideal I/O port, which can introduce an unexpected unknown transmission line between the physical reference plane and the port of the corresponding inverter in the circuit model. In this thesis, the PII response is used to determine the equivalent electrical length of this unknown transmission line. The validity of the proposed technique is demonstrated through the design of a wideband planar filter with a fractional bandwidth of 72%, the tuning of filters with transmission zeros and the design of a wideband diplexer. The multilayer superconductor technology allows to realize high-Q planar structures with highly miniature physical dimensions. The superconductor digital receivers can directly digitalize RF signals up to very high frequencies, eliminating the need to use mixers and oscillators to convert the RF signals to lower frequencies. This thesis demonstrates the feasibility of an ultra-wide band superconductor mm-Wave continuous triplexer that can be integrated with superconductor analog to digital converter (ADC) on a single niobium chip. A wideband high-Q mm-Wave highly miniature niobium-based superconductor multiplexer realized on an 8-layer niobium process has been developed, fabricated, and tested covering the frequency range 20 GHz - 80 GHz. In addition to monolithic integration of the superconductor multiplexer with the superconductor ADC, the thesis also demonstrates the feasibility of mounting the triplexer chip on a multi-chip-module (MCM) substrate using flip-chip technology interfaced with 1 mm mm-Wave connectors. This thesis also demonstrates using a unique behavior of spiral inductors designed intentionally to have a large parasitic capacitance in the realization of a tunable band reject filter. It is shown that, regardless of the operating frequency, the conductivity of the metal strips forming the inductor has a significant impact on how the spiral inductor behaves as an inductor or a capacitor. The concept is used to demonstrate a band reject filter made from a multilayer niobium circuit operating at 4 Kelvin. Such band reject filters are needed in the front-end of superconductor digital receivers to eliminate interference. Micromachining fabrication processes provide much higher manufacturing accuracy than traditional CNC machining technologies. Moreover, the DRIE silicon micromachining process is more economical for mass production and makes it possible to produce highly accurate 3D waveguide structures. This thesis presents filter designs composing of highly miniature silicon-micromachined ridge waveguide resonators. The proposed filter designs provide highly compact physical size with reasonable high Q values. An ultra-high-Q mm-Wave cavity filter employing a silicon-micromachined barrel-shape cavities operating in TE011 mode has been developed, fabricated and tested. The barrel-shape is proposed to realize a high-Q cavity, while circumventing the spurious issues of the degenerate TM modes that exist in traditional cylindrical-shape cavities. The filter was realized on silicon using DRIE techniques

SSTAC/ARTS review of the draft Integrated Technology Plan (ITP). Volume 8: Aerothermodynamics Automation and Robotics (A/R) systems sensors, high-temperature superconductivity

Viewgraphs of briefings presented at the SSTAC/ARTS review of the draft Integrated Technology Plan (ITP) on aerothermodynamics, automation and robotics systems, sensors, and high-temperature superconductivity are included. Topics covered include: aerothermodynamics; aerobraking; aeroassist flight experiment; entry technology for probes and penetrators; automation and robotics; artificial intelligence; NASA telerobotics program; planetary rover program; science sensor technology; direct detector; submillimeter sensors; laser sensors; passive microwave sensing; active microwave sensing; sensor electronics; sensor optics; coolers and cryogenics; and high temperature superconductivity

Commissioning of the KATRIN Raman system and durability studies of optical coatings in glove box and tritium atmospheres

The aim of the Karlsruhe Tritium Neutrino (KATRIN) experiment is a neutrino mass measurement with a sensitivity of 0.2 eV/c2 (90% C.L.) by the investigation of tritium beta-spectrum. It requires the continuous monitoring of the isotopic composition of the tritium gas by Raman spectroscopy. The aim of this work was to design and commission the Raman system. Special emphasize was put on the metrological performance and reliable operation over the projected operating time of several years

Radar Technology

In this book “Radar Technology”, the chapters are divided into four main topic areas: Topic area 1: “Radar Systems” consists of chapters which treat whole radar systems, environment and target functional chain. Topic area 2: “Radar Applications” shows various applications of radar systems, including meteorological radars, ground penetrating radars and glaciology. Topic area 3: “Radar Functional Chain and Signal Processing” describes several aspects of the radar signal processing. From parameter extraction, target detection over tracking and classification technologies. Topic area 4: “Radar Subsystems and Components” consists of design technology of radar subsystem components like antenna design or waveform design