Cmos Programmable Time Control Circuit Design For Phased Array Uwb Ground Penetrating Radar Antenna Beamforming

Phased array radar systems employ multiple antennas to create a radar beam that can be steered electronically. By manipulating the relative phase values of feeding signals among different antennas, the effective radiation pattern of the array can be synthesized to enhance the main lobe in a desired direction while suppressing the undesired side lobes in other directions. Hence the radar scanning angles can be electronically controlled without employing the bulky mechanical gimbal structure, which can significantly reduce radar system size, weight and power consumption. In recent years, phased array technologies have received great attentions and are explored in developing many new applications, such as smart communication systems, military radars, vehicular radar, etc. Most of these systems are narrow band systems, where the phase delays are realized with narrow band phase shifter circuits. For the impulse ground penetrating radar however, its operating frequency spans an ultrawide bandwidth. Therefore the traditional phase shifters are not applicable due to their narrow band nature. To resolve the issue, in this study, a true time delay approach is explored which can precisely control time delays for the feeding pulse signals among different antennas in the array. In the design, an on chip programmable delay generator is being developed using Global Foundry 0.18 µm 7 HV high voltage CMOS process. The time delay control is realized by designing a programmable phase locked loop (PLL) circuit which can generate true time delays ranging from 100 ps (picoseconds) to 500 ps with the step size of 25 ps. The PLL oscillator\u27s frequency is programmable from 100MHz to 500MHz through two reconfigurable frequency dividers in the feedback loop. As a result, the antenna beam angle can be synthesized to change from 9.59° to 56.4° with a step of 2.75°, and the 3dB beamwidth is 10°. The power consumption of the time delay circuit is very low, where the supply voltage is 1.8V and the average current is as low as 472uA

Cmos Programmable Time Control Circuit Design For Phased Array Uwb Ground Penetrating Radar Antenna Beamforming

Phased array radar systems employ multiple antennas to create a radar beam that can be steered electronically. By manipulating the relative phase values of feeding signals among different antennas, the effective radiation pattern of the array can be synthesized to enhance the main lobe in a desired direction while suppressing the undesired side lobes in other directions. Hence the radar scanning angles can be electronically controlled without employing the bulky mechanical gimbal structure, which can significantly reduce radar system size, weight and power consumption. In recent years, phased array technologies have received great attentions and are explored in developing many new applications, such as smart communication systems, military radars, vehicular radar, etc. Most of these systems are narrow band systems, where the phase delays are realized with narrow band phase shifter circuits. For the impulse ground penetrating radar however, its operating frequency spans an ultrawide bandwidth. Therefore the traditional phase shifters are not applicable due to their narrow band nature. To resolve the issue, in this study, a true time delay approach is explored which can precisely control time delays for the feeding pulse signals among different antennas in the array. In the design, an on chip programmable delay generator is being developed using Global Foundry 0.18 µm 7 HV high voltage CMOS process. The time delay control is realized by designing a programmable phase locked loop (PLL) circuit which can generate true time delays ranging from 100 ps (picoseconds) to 500 ps with the step size of 25 ps. The PLL oscillator\u27s frequency is programmable from 100MHz to 500MHz through two reconfigurable frequency dividers in the feedback loop. As a result, the antenna beam angle can be synthesized to change from 9.59° to 56.4° with a step of 2.75°, and the 3dB beamwidth is 10°. The power consumption of the time delay circuit is very low, where the supply voltage is 1.8V and the average current is as low as 472uA

A complete CMOS UWB timed-array transmitter with a 3D Vivaldi antenna array for electronic high-resolution beam spatial scanning

We present a new Ultra Wide Band (UWB) Timed-\ud Array Transmitter System with Beamforming capability for\ud high-resolution remote acquisition of vital signals. The system\ud consists of four identical channels, where each is formed of a\ud serial topology with three modules: programmable delay\ud circuit (PDC or τ), a novel UWB 5th Gaussian Derivative order\ud pulse generator circuit (PG), and a planar Vivaldi antenna.\ud The circuit was designed using 0.18μm CMOS standard\ud process and the planar antenna array was designed with filmconductor\ud on Rogers RO3206 substrate. Spice simulations\ud results showed the pulse generation with 104 mVpp amplitude\ud and 500 ps width. The power consumption is 543 μW, and\ud energy consumption 0.27 pJ per pulse using a 2V power\ud supply at a pulse repetition rate (PRR) of 100 MHz.\ud Electromagnetic simulations results, using CST Microwave\ud (MW) Studio 2011, showed the main lobe radiation with a\ud gain maximum of 13.2 dB, 35.5º x 36.7º angular width, and a\ud beam steering between 17º and -11º for azimuthal (θ) angles\ud and 17º and -18º for elevation (φ) angles at the center\ud frequency of 6 GH

Ultra-wideband phased array radar for short-range imaging applications

Includes abstract.Includes bibliographical references (p. 105-108).Ultra-wide band (UWB) technology, as defined by the Federal Communication Commission (FCC) on February 2002, refers to signals or systems that have bandwidth ≥500 MHz or instantaneous fractional bandwidth ≥0.20 [2]. Compared to the conventional narrowband radar that operates with the same centre frequency, UWB radar offers many advantages, including high spatial resolution, for detecting closely-spaced target; and lower probability of interception, for stealth-like military application. There are many types of UWB waveform. The most obvious and simplest-to-generate UWB waveform is the impulse or short pulse. The pulse width of these impulses is usually sub-nanosecond, which enable a range resolution of 15 cm or less, when it is being transmitted in free space

Surpassing Fundamental Limits through Time Varying Electromagnetics

Surpassing the fundamental limits that govern all electromagnetic structures, such as reciprocity and the delay-bandwidth-size limit, will have a transformative impact on all applications based on electromagnetic circuits and systems. For instance, violating principles of reciprocity enables non-reciprocal components such as isolators and circulators, which find application in full-duplex wireless radios, radar, biomedical imaging, and quantum computing systems. Overcoming the delay-bandwidth-size limit enables ultra-broadband yet extremely-compact devices whose size is not fundamentally related to the wavelength at the operating frequency. The focus of this dissertation is on using time-variance as a new toolbox to overcome these fundamental limits and re-imagine circuit and system design. Traditional non-reciprocal components are realized using ferrite materials that loose their reciprocity under the application of external magnetic bias. However, the sheer volume, cost and weight of these magnet based non-reciprocal components coupled with their inability to be fabricated in conventional semiconductor processes, have limited their application to bulky and large-scale systems. Other approaches such as active-biased and non-linearity based non-reciprocity are compatible with semiconductor processes, however, they suffer from other poor linearity and noise performance. In this dissertation, using passive transistor switch as the modulating element, we have proposed the concept of spatio-temporal conductivity modulation and have demonstrated a gamut of non-reciprocal devices ranging from gyrators to isolators and circulators. Through novel circuit topologies, for the first time, we have demonstrated on-chip circulators with multi-watt input power handling, operation at high millimeter-wave frequencies, and tailor made circulators for emerging technologies such as simultaneous-transmit-and-receive MRI and quantum computing. Delay-bandwidth-size trade-off is another fundamental electromagnetic limit, that constrains the delay imparted by a medium or a device within a fixed footprint to be inversely proportional to the signal bandwidth. It is this limit that governs the size of any microwave passive devices to be inversely proportional to its operating frequency. As a part of this dissertation, through intelligent clocking of switched capacitor networks we overcame the delay-bandwidth-size limit, thus resulting in infinitesimal, yet broadband microwave devices. Here we proposed a new paradigm in wave propagation where the properties such as the propagation delay and characteristic impedance does not depend on the constituent elements/materials of the medium, but rather heavily rely on the user-defined modulation scheme, thereby opening huge opportunities for realizing highly-reconfigurable passives. Leveraging these concepts, we demonstrated wide range of reciprocal an non-reciprocal devices including ultra-compact delay elements, highly-reconfigurable microwave passives, ultra-wideband circulators with infinitesimal form-factors and dispersion-free chip scale floquet topological insulators. Application of these devices have also been evaluated in real-world systems through our demonstrations of wideband, full-duplex receivers leveraging switched capacitors based true-time-delay interference cancelers and floquet topological insulator based antenna interfaces for full-duplex phased-arrays and ultra-wideband beamformers. Furthermore, to cater the growing RF and microwave needs of future, large-scale quantum computing systems, we demonstrated a low-cryogenic, wideband circulator based on time modulation of superconducting devices. This superconducting circulator is expected to operate alongside the superconducting qubits, inside a dilution refrigerator at 10mK-100mK, thus enabling a tightly integrated quantum system. We also presented the design and implementation of a cryogenic-CMOS clock driver chip that will generate the clocks required by the superconducting circulator. Finally, we also demonstrated the design and implementation of a low-noise, low power consumption, 6GHz - 8GHz cryogenic downconversion receiver at 4K for cryogenic qubit readout

Antennas and Propagation Aspects for Emerging Wireless Communication Technologies

The increasing demand for high data rate applications and the delivery of zero-latency multimedia content drives technological evolutions towards the design and implementation of next-generation broadband wireless networks. In this context, various novel technologies have been introduced, such as millimeter wave (mmWave) transmission, massive multiple input multiple output (MIMO) systems, and non-orthogonal multiple access (NOMA) schemes in order to support the vision of fifth generation (5G) wireless cellular networks. The introduction of these technologies, however, is inextricably connected with a holistic redesign of the current transceiver structures, as well as the network architecture reconfiguration. To this end, ultra-dense network deployment along with distributed massive MIMO technologies and intermediate relay nodes have been proposed, among others, in order to ensure an improved quality of services to all mobile users. In the same framework, the design and evaluation of novel antenna configurations able to support wideband applications is of utmost importance for 5G context support. Furthermore, in order to design reliable 5G systems, the channel characterization in these frequencies and in the complex propagation environments cannot be ignored because it plays a significant role. In this Special Issue, fourteen papers are published, covering various aspects of novel antenna designs for broadband applications, propagation models at mmWave bands, the deployment of NOMA techniques, radio network planning for 5G networks, and multi-beam antenna technologies for 5G wireless communications

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

Noncontact Vital Signs Detection

Human health condition can be accessed by measurement of vital signs, i.e., respiratory rate (RR), heart rate (HR), blood oxygen level, temperature and blood pressure. Due to drawbacks of contact sensors in measurement, non-contact sensors such as imaging photoplethysmogram (IPPG) and Doppler radar system have been proposed for cardiorespiratory rates detection by researchers.The UWB pulse Doppler radars provide high resolution range-time-frequency information. It is bestowed with advantages of low transmitted power, through-wall capabilities, and high resolution in localization. However, the poor signal to noise ratio (SNR) makes it challenging for UWB radar systems to accurately detect the heartbeat of a subject. To solve the problem, phased-methods have been proposed to extract the phase variations in the reflected pulses modulated by human tiny thorax motions. Advance signal processing method, i.e., state space method, can not only be used to enhance SNR of human vital signs detection, but also enable the micro-Doppler trajectories extraction of walking subject from UWB radar data.Stepped Frequency Continuous Wave (SFCW) radar is an alternative technique useful to remotely monitor human subject activities. Compared with UWB pulse radar, it relieves the stress on requirement of high sampling rate analog-to-digital converter (ADC) and possesses higher signal-to-noise-ratio (SNR) in vital signs detection. However, conventional SFCW radar suffers from long data acquisition time to step over many frequencies. To solve this problem, multi-channel SFCW radar has been proposed to step through different frequency bandwidths simultaneously. Compressed sensing (CS) can further reduce the data acquisition time by randomly stepping through 20% of the original frequency steps.In this work, SFCW system is implemented with low cost, off-the-shelf surface mount components to make the radar sensors portable. Experimental results collected from both pulse and SFCW radar systems have been validated with commercial contact sensors and satisfactory results are shown

1-D broadside-radiating leaky-wave antenna based on a numerically synthesized impedance surface

A newly-developed deterministic numerical technique for the automated design of metasurface antennas is applied here for the first time to the design of a 1-D printed Leaky-Wave Antenna (LWA) for broadside radiation. The surface impedance synthesis process does not require any a priori knowledge on the impedance pattern, and starts from a mask constraint on the desired far-field and practical bounds on the unit cell impedance values. The designed reactance surface for broadside radiation exhibits a non conventional patterning; this highlights the merit of using an automated design process for a design well known to be challenging for analytical methods. The antenna is physically implemented with an array of metal strips with varying gap widths and simulation results show very good agreement with the predicted performance

Beam scanning by liquid-crystal biasing in a modified SIW structure

A fixed-frequency beam-scanning 1D antenna based on Liquid Crystals (LCs) is designed for application in 2D scanning with lateral alignment. The 2D array environment imposes full decoupling of adjacent 1D antennas, which often conflicts with the LC requirement of DC biasing: the proposed design accommodates both. The LC medium is placed inside a Substrate Integrated Waveguide (SIW) modified to work as a Groove Gap Waveguide, with radiating slots etched on the upper broad wall, that radiates as a Leaky-Wave Antenna (LWA). This allows effective application of the DC bias voltage needed for tuning the LCs. At the same time, the RF field remains laterally confined, enabling the possibility to lay several antennas in parallel and achieve 2D beam scanning. The design is validated by simulation employing the actual properties of a commercial LC medium