RF Receiver Research Articles

Modulation transfer protocol for Rydberg RF receivers

We propose and demonstrate a modulation transfer protocol to increase the detection sensitivity of a Rydberg RF receiver to fields out of resonance from the transition between Rydberg levels. This protocol is based on a phase modulation of the control field used to create the Electromagnetically Induced Transparency signal. The nonlinear wave mixing of the multi-component coupling laser and the probe laser transfers the modulation to the probe laser, which is used for the RF-field detection. The measurements compare well with semi-classical simulations of atom–light interaction and show an improvement in the RF bandwidth of the sensor and an improved sensitivity of the response to weak fields.

PETcoil: first results from a second-generation RF-penetrable TOF-PET brain insert for simultaneous PET/MRI

Simultaneous positron emission tomography (PET)/magnetic resonance imaging provides concurrent information about anatomic, functional, and molecular changes in disease. We are developing a second generation MR-compatible RF-penetrable TOF-PET insert. The insert has a smaller scintillation crystal size and ring diameter compared to clinical whole-body PET scanners, resulting in higher spatial resolution and sensitivity. This paper reports the initial system performance of this full-ring PET insert. The global photopeak energy resolution and global coincidence time resolution, 11.74 ± 0.03 % FWHM and 238.1 ± 0.5 ps FWHM, respectively, are preserved as we scaled up the system to a full ring comprising 12, 288 LYSO-SiPM channels (crystal size: 3.2 × 3.2 × 20 mm3). Throughout a ten-hour experiment, the system performance remained stable, exhibiting a less than 1% change in all measured parameters. In a resolution phantom study, the system successfully resolved all 2.8 mm diameter rods, achieving an average VPR of 0.28 ± 0.08 without TOF and 0.24 ± 0.07 with TOF applied. Moreover, the implementation of TOF in the Hoffman phantom study also enhanced image quality. Initial MR compatibility studies of the full PET ring were performed with it unpowered as a milestone to focus on looking for material and geometry-related artifacts. During all MR studies, the MR body coil functioned as both the transmit and receive coil, and no observable artifacts were detected. As expected, using the body coil also as the RF receiver, MR image signal-to-noise ratio exhibited degradation (∼30%), so we are developing a high quality receive-only coil that resides inside the PET ring.

200 GHz single chip microsystems for dynamic nuclear polarization enhanced NMR spectroscopy

Dynamic nuclear polarization (DNP) is one of the most powerful and versatile hyperpolarization methods to enhance nuclear magnetic resonance (NMR) signals. A major drawback of DNP is the cost and complexity of the required microwave hardware, especially at high magnetic fields and low temperatures. To overcome this drawback and with the focus on the study of nanoliter and subnanoliter samples, this work demonstrates 200 GHz single chip DNP microsystems where the microwave excitation/detection are performed locally on chip without the need of external microwave generators and transmission lines. The single chip integrated microsystems consist of a single or an array of microwave oscillators operating at about 200 GHz for ESR excitation/detection and an RF receiver operating at about 300 MHz for NMR detection. This work demonstrates the possibility of using the single chip approach for the realization of probes for DNP studies at high frequency, high field, and low temperature.

Post Study Design of Wireless Network for the Water Dilemma in the city of Rujban

Providing water for daily life usage is one of the biggest obstacles facing the growth and development of cities not only in Libya but in many countries of the world. The city of Rujban faces this crisis despite the passage of more than five decades in trying to resolve this issue. We did some deep research and study on the water system operation problem which we divided into three parts: Karthoom Automated Control System (KACS), Idref Automated Control System 1(IACS1), Idref Automated Control System 2 (IACS2) because water is pumped on 3 different stages. The IACS1 consists of two main parts: transmitter/collector tank on one side and receiver / pumps on the other side. The transmitter end consists of a microcontroller, three stage level sensor, two water flow sensors and an RF transmitter. The other end consists of two water pumping pump and an RF receiver. The system will be automated by the use of a microcontroller in which each level of the collector tank will be designed to turn on just one or both pumps of in the case there is certain amount of water, which can be determined by water level sensor, in Karthom collection tank. A crucial part of this coordination is the flow meter which will indicate if the pump is operational or not and detect whether or not there is water leakage, all of which will be demonstrated on an LCD screen. In this paper, we will design a wireless communication network for IACS1.

Wideband-tunable microwave photonic filter using dissipative self-interference microring resonators

We propose and demonstrate a widely tunable microwave photonic filter with controlled frequency agility, bandwidth reconfigurability and flexible switching functions. It is based on the self-interference microring aided by an asymmetric Mach–Zehnder interferometer, breaking the fundamental microring footprint limit and achieving a doubled free spectral range (123.2 GHz) with a strong out-of-band rejection. Simulation results show that a bandpass microwave photonic filter can be tuned across a 60 GHz frequency range with a varied 3-dB bandwidth from 2.13 GHz to 40.7 GHz in a cascaded dual-ring topology. Its RF out-of-band rejection ratio is improved by more than 60 dB in the high frequency region due to a perfect residual phase cancellation. A dual-band notch microwave photonic filter with an extinction ratio of about 50 dB and a frequency tunable range of about 27.7 GHz is also demonstrated, showing its broadly applicability. Our method highlights its suitability to improve chip-scale wideband and high-performance RF receiver systems.

Traffic Management System Using IOT

Abstract: Traffic congestion is a major threat to transportation sector in every urban city around the world. This causes many adverse effects like, heavy fuel consumption, increased waiting time, pollution, etc. and causes major challenge to the movement of emergency vehicles. The reaction time required by the emergency responders plays a vital role to handle the situation. The greatest challenge they face is congestion of traffic flow. This paper presents an approach to schedule emergency vehicles in traffic. The approach combines the controlling of traffic congestion by IR sensors and detection of emergency vehicle using by RFID scanner method. The IR sensors is responsible for vehicle counting and RFID for the emergency vehicle. An IR sensors continuously count the passing vehicles & records the delay time between two vehicles. Flow of vehicles is normal means there is smooth traffic flow, or if in case, the passing time between two vehicles is decreased that means traffic congestion is happen ahead. In this situation traffic light turns to green, so that the emergency vehicle will reach its destination as fast as possible. The aim of this article is to identify and monitor the congestion system in order to provide efficient facilities. This journal also sets out a method that uses 433 MHZ RF Transmitter and receiver Wireless communication device technique and Internet of Things (IoT) to transmit the treatment request from the ambulance to the nearby hospitals and at the same time the LCD is installed on the road junction which displays the nearby hospital name and contact number for the ambulance, this smart traffic system which in turn changes the traffic signal cycle. This system can be implemented throughout the city thereby to reducing the delay.

Traffic Control System for Emergency Vehicle

Urbanization is growing so rapidly due to which demand is increasing in the transportation field, hence traffic control system plays an important role is handling emergency situations and disaster management. Traffic control system implementation is much necessary not only to avoid the congestion but also to provide the way for the emergency service like ambulances, fire engines etc., this protects many lives from both health and disaster sector. This will provide effectiveness to the traffic control system in both normal and emergency situations. The proposed methodology is about implementation of RF transmitter and receiver with the Arduino to automize the traffic control system to avoid the delay in the arrival of emergency vehicle at the spot where emergency is required traffic control system provides an emergency blue light along with the existing traffic lights to provide the proper indication emergency traffic signal the emergency vehicle will reach the destination without any delay in traffic. This protects many lives from both health and disaster sector. This will provide effectiveness to the traffic control system in both normal and emergency situations. 

IOT Based Accident Alert System

Abstract: Transportation has great importance in our daily life and it’s development has made many of our chores much easy. IoT based accident alert system aims to provide real-time warnings to drivers as they approach hazardous areas using ESP32 Ultrasonic Sensors and RF Transmitter and Receiver has gained attention. When a vehicle or a car comes near the accident prone area, ESP32 alongwith Speaker and Audio amplifier whichis situated in a car produces a beep sound through which the driverin the car getsan alarmsound that thereis an accident prone area nearby.

A High Gain Concurrent Dual-band Low-Noise Amplifier in 130-nm BiCMOS Technology

This paper presents a fully integrated concurrent 15/30-GHz dual-band low-noise amplifier (LNA). The proposed concurrent LNA IC is designed and simulated in 130-nm BiCMOS technology. The new passive LC notch filter is proposed to realize high gain and low noise figure over dual-band frequency, simultaneously. The simulated BiCMOS LNA IC has exhibited peak gains of 30.1/23.7 dB at 15/30-GHz, respectively, with 20-mW power consumption from 1-V supply. The concurrent dual-band LNA achieves noise figure of 2.2/2.9-dB and IIP3 of -18.2/-8.8 dBm at the respective passbands. Therefore, the proposed dual band concurrent LNA IC is applicable to front-end RF receivers for Ku-Band and Ka-Band systems.

Beneficial Effects of Self-Motion for the Continuous Phase Analysis of Ac-Coupled Doppler Radars

This paper analyzes the beneficial effects on phase detection arising from the motion of an ac-coupled Doppler radar. Indeed, although the presence of an ac coupling stage suppresses the dc offset after the receiver RF output, due to the coupling capacitor, a high-pass behavior is introduced; the presence of a high-pass behavior leads to signal distortion, particularly for low Doppler frequencies, which are typical in many biomedical or industrial applications. Since the target displacement is usually extracted from the phase history, this effect might, in turn, worsen the overall accuracy of the system. Moreover, if the target alternates stationary and moving time intervals, the phase detection step becomes challenging. Indeed, during the stationary time, the output of the RF front-end shows only noise fluctuations that, in turn, result in uncorrelated phases which might be confused with the real target displacement. This negative effect might be avoided by keeping the radar continuously moving, thus exploiting what is usually considered a state that is negative and worthy of attention. In this contribution, this effect is addressed from a different perspective, and ad hoc experimental case studies are shown to demonstrate the effectiveness of the proposed system. This task has been accomplished through theoretical analysis and related experimental activity.

A cryogenic tune and match circuit for magnetic resonance microscopy at 15.2T

Background and SignificanceAchievable signal to noise ratios (SNR) in magnetic resonance microscopy images are limited by acquisition times and the decreasing number of spins in smaller voxels. A common method of enhancing SNR is to cool the RF receiver coil. Significant SNR gains are realized only when the Johnson noise generated within the RF hardware is large compared to the electromagnetic noise produced by the sample. Cryogenic cooling of imaging probes is in common use in high field systems, but it is difficult to insulate a sample from the extreme temperatures involved and in practice imaging cryoprobes have been limited to surface or partial volume designs only. In order to use a solenoid in which the windings were not directly cooled and in close proximity to the sample, we designed a chamber to cool only the tune and match circuitry and show experimentally it is possible to achieve much of the theoretically available SNR gain. MethodsA microcoil circuit consisting of two tuning capacitors, one fixed capacitor, and SMB coaxial cable was designed to resonate at 650 MHz for imaging on a Bruker 15.2 T scanner. Sample noise increases with the sample diameter, so surface loops and solenoids of varying diameters were tested on the bench to determine the largest diameter coil that demonstrated significant SNR gains from cooling. A liquid N2 cryochamber was designed to cool the tune and match circuit, coaxial cable, and connectors, while leaving the RF coil in ambient air. As the cryochamber was filled with liquid N2, quality factors were measured on the bench while monitoring the coil's surface temperature. Improvements of SNR on images of ionic solutions were demonstrated via cooling the tune and match circuit in the magnet bore. ResultsAt 650 MHz, loops and solenoids < 3 mm in diameter showed significant improvements in quality factor on the bench. The resistance of the variable capacitors and the coaxial cable were measured to be 45% and 32% of room temperature values near the Larmor frequency. Images obtained with a 2 turn, 3 mm diameter loop with the matching circuit at room temperature and then cooled with liquid nitrogen demonstrated SNR improvements of a factor of 2. ConclusionsBy cooling the tune and match circuit and leaving the surface loop in ambient air, SNR was improved by a factor of 2. The results are significant because it allows for more space to insulate the sample from the extreme temperatures used in imaging cryoprobes.

Comparing 3rd-Order Digital Modulation Schemes for SEU Resilience in RF Receivers due to SETs in the SiGe LNA

Comparing 3^rd-Order Digital Modulation Schemes for SEU Resilience in RF Receivers due to SETs in the SiGe LNA

A 0.5-8GHz Reconfigurable CMOS RF Receiver Front-end for CR and DPA Applications

A 0.5-8GHz Reconfigurable CMOS RF Receiver Front-end for CR and DPA Applications

Comparing Digital Modulation Schemes in RF Receivers for Bit Errors Induced by Single-Event Transients in the Low Noise Amplifier

Comparing Digital Modulation Schemes in RF Receivers for Bit Errors Induced by Single-Event Transients in the Low Noise Amplifier

Realizing Joint Communication and Sensing RF Receiver Front-Ends: A Survey

Realizing Joint Communication and Sensing RF Receiver Front-Ends: A Survey

Direction-agnostic gesture recognition system using commercial WiFi devices

In recent years, channel state information (CSI) has been used to recognize hand gestures for contactless human–computer interaction. However, most existing solutions require precision hardware or prior learning at the same angle both during training and for inference/training in order to achieve high recognition accuracy. This requirement is unrealistic for practical instrumentation, where the orientation of a subject relative to the RF receiver may be arbitrary. We present direction-agnostic hand gesture recognition utilizing commercial WiFi devices to overcome low accuracy in non-trained observation angles. To achieve equal conditions in all recognition angles, first of all, through the circular antenna arrangement to mitigate the impact of user direction changes. Then, the orientation of users is estimated by the Fresnel zone model. Finally, the feature mapping model of users in different orientations is established, and the gesture features in the estimated direction are mapped to the benchmark direction to eliminate the influence caused by the change of user orientation. Experimental results in a typical indoor environment show that WiNDR has superior performance, and the average recognition accuracy of five common gestures is 92.38%.

A wideband low power RF Receiver Front-End for Internet-of-Things applications

This paper presents a broadband RF receiver front-end circuit that offers advantages in both area and power consumption. The design features an innovative dual-path noise-canceling Low-Noise Amplifier (LNA) circuit, achieving impedance matching and balun functionality without the need for on-chip inductors. The RF receiver front-end circuit comprises a I and Q doublebalanced quadrature passive mixers and an 25% duty-cycle LO generator. The circuit’s broadband characteristics enable it to operate across a wide range of frequency bands. It is implemented using a 65 nm CMOS process. The core circuit, including both RF and baseband signal paths, consumes a mere 12 mW of power. Test results demonstrate that the RF receiver front-end circuit achieves a conversion gain of 35–40 dB, a noise figure (NF) below 4.8 dB, and a minimum third-order intercept point (IIP3) exceeding −6.8 dBm over the 0.1–3.1 GHz frequency range. The chip’s overall footprint is compact at 0.9 mm2, with the entire RF signal path powered by a 1 V supply, offering clear advantages in terms of compactness and low power consumption.

Radiation damping at clinical field strength: Characterization and compensation in quantitative measurements.

In any MR experiment, the bulk magnetization acts on itself, caused by the induced current in the RF receiver circuit that generates an oscillating damping field. This effect, known as "radiation damping" (RD), is usually weak and, therefore, unconsidered in MRI, but can affect quantitative studies performed with dedicated coils that provide a high SNR. The current work examined RD in a setup for investigations of small tissue specimens including a quantitative characterization of the spin-coil system. A custom-made Helmholtz coil (radius and spacing 16 mm) was interfaced to a transmit-receive (Tx/Rx) switch with integrated passive feedback for modulation or suppression of RD similar to preamplifier decoupling. Pulse sequences included pulse-width arrays to demonstrate the absence/ presence of RD and difference techniques employing gradient pulses or composite RF pulses to quantify RD effects during free precession and transmission, respectively. Experiments were performed at 3T in small samples of MnCl2 solution. Significant RD effects may impact RF pulse application and evolution periods. Effective damping time constants were comparable to typical T2 * times or echo spacings in multi-echo sequences. Measurements of the phase relation showed that deviations from the commonly assumed 90° angle between the damping field and the transverse magnetization may occur. Radiation damping may affect the accuracy of quantitative MR measurements performed with dedicated RF coils. Efficient mitigation can be achieved hardware-based or by appropriate consideration in the pulse sequence.

Wireless Animatronic Hand

As a result of employees utilizing their bare hands, there are more accidents in industries every year. Animatronic hands resemble human hands and are capable of carrying out a variety of tasks that humans are unable to do. Human hands cannot readily finish difficult tasks, but animatronic hands can mimic human movements and complete them. A number of actuators and sensors make up the robotic hand, which are managed by a person's hand. The pushers control how far the fingers can move. We employ flex sensors to detect the positions. The positions and motion of the hand are reported by sensors to Arduino. The microcontroller uses a 433MHz transmitter and receiver in both transmitter and receiver side to used for transmitting the data, so it will be access in remote area. We employ servo motors as actuators by getting the position and motion from another microcontroller also attached. Two microcontrollers are interconnected with 433MHz transmitter and receiver, Transmitter and receiver for 433 MHz When sending and receiving radio signals between any two devices, RF refers to a set of electronic RF transmitters and receiver modules. The transmitter module at the transmitter end transmits the data, which the receiver module at the receiver end receives.

Design and Optimization of an Ultra-Low-Power Cross-Coupled LC VCO with a DFF Frequency Divider for 2.4 GHz RF Receivers Using 65 nm CMOS Technology

This article presents the design and optimization of a tunable quadrature differential LC CMOS voltage-controlled oscillator (VCO) with a D flip-flop (DFF) frequency divider. The VCO is designed for the low-power and low-phase-noise applications of 2.4 GHz IoT/BLE receivers and wireless sensor devices. The proposed design comprises the proper stacking of an LC VCO and a DFF frequency divider and is simulated using a TSMC 65 nm CMOS technology, and it has a tuning range of 4.4 to 5.7 GHz. The voltage headroom is preserved using a high-impedance on-chip passive inductor at the tail for filtering and enabling true differential operation. The VCO and frequency divider consume as low as 2.02 mW altogether, with the VCO section consuming only 0.47 mW. The active area of the chip including the pads is only 0.47 mm2. The designed VCO achieved a much better phase noise of −118.36 dBc/Hz at a 1 MHz offset frequency with 1.2 V supply voltages. The design produced a much better FoM of −196.44 dBc/Hz compared to other related research.