Effective Isotropic Radiated Power Research Articles

A Design of a High-Performance Analog Front-End for Passive UHF RFID Tag EPC C1G2

This paper introduces a high-performance analog front end for passive UHF RFID tag compatible with the EPC Class-1 Generation 2 (EPC C1G2) standard protocol. The proposed front end of a passive tag which contains the following modules: a power generation circuit which is composed of a matching circuit and an RF-limiter circuit, an NMOS rectifier, a DC limiter, a voltage regulation, a modulation and ASK demodulation circuit, a power-on-reset circuit, a ring oscillator which generates a clock of 1.28 MHz. The originality of this work is the proposal of a voltage regulation circuit composed of two distinct LDO regulators that share the same reference voltage and are designed to generate a Vdd1 (0.5 V) for the analog supply and Vdd2 (1 V) for digital power supply, under conditions of 50 Ω antenna, 900 MHz, a sensitivity of -24 dBm and a maximum consumption of 1 µW. The operating distance of the RFID is more than 25 meters based on the regulated 4 W effective isotropic radiated power (EIRP). The chip area of the proposed analog front end is only 79 μm × 83 μm . The simulation results in 90 nm CMOS process confirm the performance of the proposed analog front-end.

Compact Folded Dipole With Embedded Matching Loop for Universal Tag Applications

A coin-shaped folded dipole is proposed for designing a UHF tag that can be placed in free space and on metal. The proposed tag antenna is compact ( $0.095\lambda )$ and low in profile (1.6 mm). It is composed of a matching loop, which is encircled by two patch-shaped radiating arms, forming an embedded structure that has high compactness. Slots are etched in the radiators for fine-tuning the resonant frequency. An equivalent circuit has also been obtained for analyzing the impedance characteristics of the tag antenna across the frequency range, and it is found that the radiating element itself is capacitive and inclusion of the matching loop is essential for making the tag antenna inductive for achieving good matching with the chip. Simulation and experiment have been conducted to study the charateristics of the proposed tag antenna. When tested in free space with an Effective Isotropic Radiated Power (EIRP) input power of 3.28 W, the tag antenna is able to reach a maximum read range of 5.2 m, but it reduces to 1.8 m when placed on metal. Also, the resonant frequency of the proposed tag antenna is found to be stable and not affected much by its backing object.

Dynamic Waveform Shaping With Picosecond Time Widths

In this paper, we present a scalable architecture in silicon that allows synthesis and dynamic waveform shaping of periodic mm-wave signals, either generated on-chip or quasi-optically through radiation in free space capable of producing pulse trains with picosecond time signatures. This is achieved through an architecture that allows extraction of multiple harmonics above $f_{\mathrm {max}}$ with simultaneous amplitude and phase control. Signal synthesis is achieved through controlled interference of multiple traveling waves with rich harmonic components and delays. The first example, presented in this paper, is where the signal synthesis is achieved on-chip demonstrating a pulse train at the output with a measured pulsewidth of 2.6 ps and a 0.46-mW output power. The second example is a four-element array with integrated antennas, which allows signal synthesis in space and is demonstrated to show reconfigurable radiation of pulse trains with a 2.6-ps pulsewidth, pure tones at a fundamental frequency of 107.5 GHz with an effective isotropic radiated power (EIRP) of 4.6 dBm and a second harmonic of 215 GHz with EIRP of 5.0 dBm, as well as any combination of these two harmonics with arbitrary amplitudes and delays. To the best of the authors’ knowledge, this paper demonstrates the sharpest on-chip and radiated pulses with dynamic waveform shaping in any integrated circuit technology. This can open the door to innovations in broadband terahertz imaging, sensing, and spectroscopy.

A Distributed Power-Amplifying Reflectarray Antenna for EIRP Boost Applications

The distributed power-amplifying capability is investigated to improve the effective isotropic radiated power (EIRP) of reflectarray antennas. For experimental verification purpose, a C-band power-amplifying reflectarray with 12 × 12 elements is designed and fabricated, where the aperture-coupled patch element with orthogonal H-shaped slots and an integrated power amplifier is employed. Element simulations show that the reflection coefficients are below −10.0 dB and the isolation is better than 31.8 dB for various lengths of microstrip line and oblique incident angles at the design frequency of 5.8 GHz. The measured results of the reflectarray prototype show that well-defined radiation patterns are achieved, with the measured active gain of 37.4 dBi and the measured directivity of 27.3 dBi. The nonlinearity performance of the prototype is also analyzed and measured. The measured input power at 1 dB compression point (P1dB) is 24.8 dBm, with an EIRP of 61.2 dBm.

Design of a compact multilayer circularly polarized phased array transmit antenna system for satellite applications

An active phased array antenna which can scan its beam direction to a wide range of scan angles is presented in this paper. The paper proposes a new technique to compact a phased array antenna and making it suitable for applying in satellite payloads. This antenna should transmit high data rate signal from satellite to ground stations; and by spatial power combining the needed Effective Isotropic Radiated Power (EIRP) for the transmission link will be provided. The main beam can be scanned to 50° from normal. Polarization of the radiated wave of this antenna is circular. The designed antenna benefits from microstrip technology and has a unique low mass multilayer structure with two different substrates. For implementing antenna’s RF circuits, Microwave Monolithic Integrated Circuits (MMICs) have been used and they are integrated expertly with microstrip radiators. Beam controller board sends necessary commands to MMICs for setting phase and amplitude of each array module. For decreasing side lobe level in high scan angles, genetic algorithm is applied and excitations of array elements are optimized. Design stages and simulation results of the array antenna are summarized in this paper and the results are compared with test results.

245-GHz Transmitter Array in SiGe BiCMOS for Gas Spectroscopy

A 245-GHz transmitter (TX) array with an integrated antenna-array for a gas spectroscopy system has been realized. It consists of a push-push VCO with a 1/64 frequency divider, power amplifiers, frequency doublers, and on-chip antennas with localized backside etching. The TX-frequency is tunable in the range from 238 to 252 GHz. The TX-array has been fabricated in a 0.13- μm SiGe:C BiCMOS technology with f T /f max of 300 GHz/500 GHz. Its output power is approximately 7 dBm at 245 GHz, and the effective isotropically radiated power (EIRP) reaches 18 dBm at 245 GHz. The main components of the gas spectroscopy system are a TX and a receiver (RX) in SiGe BiCMOS as well as a gas absorption cell. The sensitivity of this spectroscopy system is demonstrated by measuring the high-resolution absorption spectrum of gaseous methanol ( CH3OH). Due to the increased power provided by the TX-array, the sensitivity of the spectrometer can be increased significantly.

Passive and Semi-Passive Wireless Temperature and Humidity Sensors Based on EPC Generation-2 UHF Protocol

This paper proposes passive and semi-passive wireless temperature and humidity sensors based on electronic product code (EPC) global Class-1 Generation-2 UHF communication protocol. The wireless sensors consist of a sensor key chip and off-chip temperature and humidity sensors. The sensor key chip integrates RF/analog front-end circuit, digital baseband processor, nonvolatile memory, on-chip temperature sensor, and sensor interface. The sensor interface connects the off-chip sensors and the sensor key chip. The sensor key chip with the on-chip temperature sensor can operate without battery power (passive mode), and also can co-operate with the off-chip temperature and humidity sensors powered by battery (semi-passive mode). The RF/analog front-end circuit provides the dc power to the sensor key chip and communicates with the interrogator passively. Advanced low-power techniques are adopted to reduce the power consumption of the sensor key chip. The sensor key chip is fabricated in 0.18- $\mu $ m CMOS process. In passive mode, the maximum wireless sensitivity of on-chip sensor is −15.1/−11.2 dBm for reading and sensing operation, respectively, and the temperature sensing error is −1 °C/0.8 °C over operating range from −20 °C to 50 °C. It achieves a reading/sensing distance of over 9.5/6 m with 4-W effective isotropic radiated power (EIRP) by the commercial interrogator. In semi-passive mode, the temperature and humidity sensing distance of off-chip sensors is 2.7 m.

High throughput satellite systems: An analytical approach

KA-SAT has represented a new generation of high throughput satellites (HTS) with the largest number of spots delivering a capacity of 90 Gbit/s for a wide variety of services ranging from internet access in homes to satellite news gathering and domestic broadcasting. HTS systems require a critical approach in terms of communication system requirements and payload analysis. This paper presents the typical system architecture of such systems and provides an analytical approach to elements that are required for the estimation of forward and return capacity, the key factor in these systems. These elements include the effective isotropic radiated power (EIRP) and the gain over noise temperature (G/T) cumulative densities, the carrier-to-inference (C/I) estimations and the capacity assessment for the forward and return links.

Pattern-Reconfigurable Self-Oscillating Active Integrated Antenna With Frequency Agility

A frequency-agile pattern-reconfigurable self-oscillating active integrated antenna (AIA) is investigated in this paper. With the aid of two PIN diodes and a varactor, the proposed active antenna shows pattern reconfigurability and frequency tunability at the same time. The antenna, composed of two monopoles and a semi-ring radiator, can be switched between four states, with two featuring omnidirectional patterns and the other two having end-fire radiation. The polarizations of the two omnidirectional states are spatially orthogonal to each other. By embedding a varactor diode, the voltage-controlled tuning range is from 4.27 to 4.94 GHz, while the effective isotropic radiated power (EIRP) varies from 5.4 to 9.3 dBm. The phase noise is better than ${-}102.7$ dBc/Hz at a 1-MHz offset from the carrier frequency.

Ultrawideband Signals in Medicine [Life Sciences

In the last decade, the utilization of radio technology for a variety of clinical and medical applications has increased dramatically. Advances in microelectronics have enabled the miniaturization and integration of biomedical sensors and radio transceivers into single units. Such wireless sensors can be worn or implanted, and they facilitate the continuous collection and transmission of physiological signals. The centrally coordinated or distributed interconnection of wireless biomedical sensors, referred to as a body area network (BAN), has already been standardized in IEEE Standard 802.15.6-2012. Besides narrowband (NB), IEEE Standard 802.15.6-2012 supports the use of ultrawideband (UWB) radio interfaces for wearable sensors. The U.S. Federal Communications Commission (FCC) defines UWB signals to be those with fractional bandwidth exceeding 20% of the center frequency, or alternatively, a bandwidth greater than 500 MHz. A number of techniques can be used to generate UWB signals; the most widely used is the one referred to as impulse radio (IR) and consists of transmitting very narrow pulses in the time domain, commonly in the order of a few nanoseconds with fast rise times reaching 50 ps [1]. Another common approach to generate UWB signals is subcarrier aggregation in orthogonal frequency-domain multiplexing (OFDM), which is generally used for short-range nonmedical indoor communications. The very large bandwidth enables high-data-rate communications. In the presence of noise and power constraints, UWB allows trading a section of the ?bandwidth for power according to the Shannon?Hartley theorem. This means UWB communication systems can operate with ultralow power and low signal-to-noise ratio (SNR) using different modulation and coding strategies. UWB signals have other inherent characteristics that make them suitable for the wireless interface of wearable biomedical sensors. Noiselike behavior due to the extremely low maximal effective isotropically radiated power (EIRP) spectral density of ?41.3 dBm/MHz makes UWB signals difficult to detect by NB systems and robust against jamming, potentially rescinding the need for complex encryption algorithms. Additionally, UWB signals do not represent a threat to patients? safety [2]. Much research has been done toward the use of BAN technology for ubiquitous monitoring of patients suffering from chronic diseases. Nevertheless, the commercial use of UWB for BAN has been limited in part by the FCC regulations, which restrict the communication applications to 3.1?10.6 GHz where propagation conditions in the body environment are rather unfavorable.

Development of one-minute rain-rate and rain-attenuation contour maps for satellite propagation system planning in a subtropical country: South Africa

Millimeter and microwave system design at higher frequencies require as input a 1-min rain-rate cumulative distribution function for estimating the level of degradation that can be encountered at such frequency bands. Owing to the lack of 1-min rain-rate data in South Africa and the availability of 5-min and hourly rainfall data, we have used rain-rate conversion models and the refined Moupfouma model to convert the available data into 1-min rain-rate statistics. The attenuation caused by these rain rates was predicted using the International Telecommunication Union (ITU) recommendations model. The Kriging interpolation method was used to draw contour maps over different percentages of time for spatial interpolation of rain-rate values into a regular grid in order to obtain a highly consistent and predictable inter-gauge rain-rate variation over South Africa. The present results will be useful for system designers of modern broadband wireless access (BWA) and high-density cell-based Ku/Ka, Q/V band satellite systems, over the desired area of coverage in order to determine the appropriate effective isotropically radiated power (EIRP) and receiver characteristics of this region.

A 160 GHz Pulsed Radar Transceiver in 65 nm CMOS

This paper presents a 160 GHz center frequency pulsed 65 nm CMOS transceiver for short range radar applications. Four phased array transceivers were implemented in a single chip with antennas implemented in a BGA package. The implemented transmitter is capable of producing pulses of 100 ps widths ( >20 GHz RF bandwidth) at a 160 GHz carrier frequency. The measured effective isotropic radiated power (EIRP) is 18.8 dBm for continuous wave outputs. The analog beam forming receiver achieves an overall gain of 42.5 dB, -14 dBm IP1dB, 7 GHz bandwidth, and a noise figure of 22.5 dB. The sliding window time-dilation baseband relaxes the output data rate and subsequent digital processing requirements. Fine grained duty cycling reduces power dissipation. The entire chip consumes 2.2 W from 1.2/1.4 V supplies in a 65 nm digital CMOS process.

Radiation Characteristics of 3D Resonant Cavity Antenna with Grid-Oscillator Integrated Inside

A three-dimensional (3D) rectangular cavity antenna with an aperture size of 80 mm×80 mm and a length of 16 mm, integrated with a four-MESFET transistor grid-oscillator, is designed and studied experimentally. It is found that the use of 3D antenna resonant cavity in case of small or medium gain microwave active cavity antenna leads to effective and stable power combining and radiation. The lack of lateral cavity diffraction and radiation helps in producing a directive gain of about 17 dB and radiation aperture efficiency bigger than 75% at a resonance frequency of 8.62 GHz. Good DC to RF oscillator efficiency of 26%, effective isotropic radiated power (EIRP) of 5.2 W, and SSB spectral power density of −82 dBc/Hz are found from the measured data. The 3D antenna cavity serves also as a strong metal container for the solid-state oscillator circuitry.

2-D Direct-Coupled Standing-Wave Oscillator Arrays

A direct-coupled technique for standing wave oscillator (SWO) arrays is presented in this paper. The oscillation currents of a unit cell in the SWO array directly inject to adjacent cells through the resonator. Two 2-D SWO arrays based on the technique are reported. The first SWO array can provide synchronous signals with identical frequencies, amplitudes, and phases at multiple locations over a chip. It is implemented in a 90-nm CMOS technology with 61.5-GHz oscillation frequency. Millimeter-wave radiators that consists of the proposed SWO array, an RF driver array, and an on-chip loop antenna array are implemented in a single chip to verify the synchronicity of the reported 2-D SWO via wireless measurement. The indirect evidence of synchronicity is provided from the correlation between the wireless measured effective isotropic radiated power (EIRP) and phase noise of 1 × 1, 2 × 2, and 3 × 3 arrays. The EIRP in the normal direction of the array is increasing by a factor of 10 log N <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and the phase noise is reducing by a factor of 10 log N over that of a single cell, where N is the number of unit cells in the array. The second SWO array can provide synchronous signals with identical frequencies, amplitudes, and multiple phases at multiple locations over a chip. It is implemented in a 65-nm CMOS technology with 132.5-GHz fundamental frequency. The SWO array is designed for a 2-D second-harmonic (265 GHz) spatial power radiating and combining array. The EIRPs of the fundamental frequency and second harmonic in the normal direction of the array are -34 and -6.5 dBm, respectively. The phase noise of the fundamental frequency and second harmonic at 1-MHz offset from the carrier frequency are -96 and -89 dBc/Hz, respectively.

Full duplex reflection amplifier tag

The authors describe a reflection amplifier adapted to have both a reflection and a transmission port. The amplifier uses a single silicon bipolar transistor and demonstrates a reflection gain of 13 dB, transmission gain of 10 dB and 3.4 dB noise figure at 5.25 GHz. The added feature of transmission gain in the reflection amplifier permits practical implementation of full duplex microwave radiofrequency indentification (RFID) tag operation. By using a simple subcarrier modulation scheme full duplex RFID operation utilising this amplifier is demonstrated. These results indicate that for 27 dBm (0.5 W) effective isotropic radiated power (EIRP) transmit power it should be possible to obtain approximately 8 m downlink range and 25 m uplink range.

Dual Circularly Polarized Spherical Phased-Array Antenna for Spacecraft Application

Design aspects of an active spherical phased-array antenna (SPAA) operating in dual circularly polarized (CP) mode are discussed here. Dual CP configuration with good cross-polarized isolation enables frequency reuse using polarization diversity. This design also implements sharing of the resources like amplifiers and phase shifters in an optimal way to reduce mass, power requirement, and cost of the antenna. The antenna is hemispherical in shape and maintains required effective isotropic radiated power (EIRP) over a hemispherical coverage area. Detailed analysis including the effect of failure of a few of the elements of the array and the measured results of the antenna at X-band are discussed here. This antenna has been used for transmission of payload data from a low Earth orbit satellite of ISRO.

Capacitively Loaded, Inductively Coupled Fed Loop Antenna With an Omnidirectional Radiation Pattern for UHF RFID Tags

A capacitively loaded, inductively coupled fed loop antenna with an omnidirectional radiation pattern for UHF radio frequency identification (RFID) tags is proposed. The inductively coupled feed structure is beneficial for conjugate impedance matching. The loaded capacitors in the radiating and feeding loops allow for easy control of the resonant frequency and the antenna reactance, respectively. The omnidirectional radiation pattern on the horizontal plane makes the proposed tag insensitive to be mounted on different target objects. With a small size of 43 × 43 mm2, the measured maximum reading range of the prototype is 9.5 m with a total transmitted power of 4.0 W effective isotropic radiated power (EIRP).

Satellite broadcast usage and life test of high power S-band Traveling Wave Tube Amplifiers

Broadcasting radio programs from satellites to mobile users has been operating for many years in the United States, Canada and South Korea. The service, generally called Satellite Radio, is provided at S-band radio frequencies. Satellite Radio users require near perfect service availability. Since most users are mobile (automobiles and handheld reception), the antennas of their receivers have little gain necessitating very high effective isotropic radiated power (EIRP) from the satellite to provide the required availability particularly under fading conditions. Despite using a satellite directive transmitting antenna, the achievement of this high EIRP requires a satellite transmitter radio frequency power output of over 7kW. This is typically achieved by paralleling 32 Traveling Wave Tube Amplifiers (TWTAs). The configuration, usage and technical aspects of such satellite transmitters are described. These satellite transmitters are critical to Satellite Radio service both for performance and for operating lifetime, typically over 15 years. Because of this importance, detailed lifetime laboratory testing is being done on the TWTAs as reported herein.

Performance Evaluation of UWB Wireless Link

An Ultra wideband technology played an important role in home networks to facilitate the transmission of multimedia contents between two consumer devices using wireless USB. This paper investigated the performance of UWB Transmitter-Receiver system, based on 2-dimensional hermite modulation, in view of its practical implementation. Performance of the UWB system was evaluated here with a cost effective and simple receiver structure, for short distance communication of 4 meters, by limiting the transmitter power, to maintain the Effective Isotropic Radiated Power (EIRP) of -41.3dBm/MHz as per FCC rule for UWB radio. The performance of the said system was also analyzed for different data rates using different sampling frequencies over multipath UWB channel, with and without the use of error correcting code. Simulations were performed in MatLAb Simulink for single user, for the image transmission application, as an extension to the previous work. System BER of 10e-5 was required to receive an image with 100% accuracy at the receiver end. It was observed that over UWB channel, at 10 GHz sampling rate, with 1.5 ns pulse width and with 10dBm transmission power, an image was received accurately at symbol SNR of 35dB without ECC and that of 12dB with (8 2 5) double error correcting code, of ¼ code rate designed in earlier work. The simulation results presented in this paper support the future implementation of UWB system that is cheaper and simpler for better performance.

Min-Max Criterion for Global Link Budget Analysis of Digital Channelized SATCOM System and Classical Transponder System

A min-max criterion is proposed to implement global link budget analysis for both digital channelized satellite communication (SATCOM) systems and classical transponder systems, and a variable neighborhood search (VNS) based algorithm is put forward for interpreting the proposed min-max criterion. With the combination of the min-max criterion and the VNS-based algorithm, both the optimal gain of each subchannel and the uplink effective isotropic radiated power (EIRP) can be obtained simultaneously. By minimizing the maximum of carrier powers output from the satellite transponder, the proposed criterion aims at reducing the difference among carrier powers in the satellite transponder as much as possible to avoid carrier power being irregular so that we can optimally set the transponder's operating point to improve the transponder power utility, and minimize each terminal's uplink EIRP so that as many links as possible could be supported and thus the system capacity could be enhanced. Furthermore, this proposed approach is generalized to analyze the capacity of classical transponder systems. Practical examples are also presented to verify the proposed approach's superior performance in improving a digital channelized SATCOM system's capacity.