Equivalent Isotropic Radiated Power Research Articles

A review of the BuFeng-1 GNSS-R mission: calibration and validation results of sea surface and land surface

ABSTRACT In this paper, we will conclude the results of Bufeng-1 (BF-1) A/B data processing, calibration workflow, and validation of the calibrated sea surface winds, land surface soil moisture, and sea surface height measurements. Since 2019, the BF-1 mission has operated in-orbit for over 4 years. The Earth reflected delay Doppler maps (DDMs) are continuously collected to perform global sea surface and land observations. At the same time, the intermediate frequency (IF) raw data are also obtained for 12 seconds every pass in diagnostic mode. To begin with, a brief description of the spaceborne Global Navigation Satellite System Reflectometry (GNSS-R) technique will be provided in the introduction. Next, we will present the overview of Chinese BF-1 mission and the data specifications used in our research. In the next section, the BF-1 mission-related spaceborne power calibration and validation are presented to show the support to power DDM observable production for sea surface and land surface applications. Then, the status of Chinese Beidou System (BDS) Equivalent Isotropic Radiated Power (EIRP) acquisition programme is then introduced. Furthermore, the latest sea surface height (SSH) measurements results including two modes (group delay and carrier phase) and wind speed derivation based on machine learning (ML) method will be spatial-temporal aligned and validated with auxiliary datasets including Denmark Technology University (DTU) mean sea surface (MSS) products and European Centre for Medium-Range Weather Forecasts (ECMWF) ERA5 reanalysis. The previous published results of sea surface winds retrieval under Hurricane conditions and soil moisture retrieval are also reviewed for the BF-1 mission applications. Finally, the conclusion of BF-1 derived results will be discussed to draw out ongoing/future works.

An EIRP Measurement Method of High-Power Microwave Systems Based on Near-Field Testing

The equivalent isotropic radiated power (EIRP) of high-power microwave (HPM) systems is a core-evaluating indicator. In practical testing, locating a suitable test site for the far-field method becomes challenging due to the requisite antenna separation. The conventional near-field method necessitates the extraction of the antenna’s near-field distribution, resulting in a testing system of intricate complexity and diminished efficiency. Therefore, the traditional near-field method cannot be directly applied in HPM systems. In the present study, a new EIRP measurement method for HPM systems based on near-field testing was proposed. First, a monitoring antenna of a considerable scale is positioned within the near-field vicinity of the HPM antenna to capture radiation power, thereby deriving its equivalent input power. Subsequently, according to the EIRP definition and the measured gain of the HPM antenna, the EIRP of the HPM system can be acquired. Theoretical research on this measurement method was conducted, the electromagnetic simulation model was constructed, and a comprehensive analysis through simulation was undertaken. A measurement system was developed and verified experimentally. The results demonstrate the precision of this approach in determining the EIRP of the HPM system, thereby serving as a valuable tool for assessing the power-handling capability of the HPM antenna. The test error is ±0.5 dB.

RF Packaging and Design for Development of High Performance 5G mmWave Modules

5G sub-6GHz networks have already been deployed in many regions around the world. However, the deployment of 5G mmWave networks is yet to meet expectations. This is partly because of the challenges associated with hardware development of 5G mmWave systems. One example of such a challenge is to overcome the severe degradation of signal-to-noise (SNR) ratio due to intra- and inter-system signal losses at mmWave frequencies. This deteriorates the signal quality, limits transmission distances and may lead to unreliable mobile communication. In this work, we present RF packaging platforms and technologies as well as an approach for scalability of 5G RF frontend integrated circuits (ICs) and antennas which overcome intra- and inter-system losses. This leads to the development of high-performance and scalable 5G MIMO (multiple input multiple output) modules for reliable mobile communication at mmWave frequencies. The platforms provide very short and low-loss signal paths with few geometrical discontinuities between the frontend ICs and antennas. This leads to significant reduction in signal reflections and attenuation, thus improving the matching efficiency of the antennas and the equivalent isotropic radiated power (EIRP) of the entire system. The platforms also enable antennas to be integrated on layers directly above the ICs, and thereby ensures scalability of the ICs and antennas in both lateral dimensions for 5G mmWave massive MIMO. To demonstrate the functionality of our proposed packaging platforms, technologies and antennas, we performed in-depth RF designs, measurements and characterization of packaging materials, technologies and platforms as well as antennas for 5G mmWave applications.

A Search for Technosignatures Around 11,680 Stars with the Green Bank Telescope at 1.15–1.73 GHz

We conducted a search for narrowband radio signals over four observing sessions in 2020–2023 with the L-band receiver (1.15–1.73 GHz) of the 100 m diameter Green Bank Telescope. We pointed the telescope in the directions of 62 TESS Objects of Interest, capturing radio emissions from a total of ∼11,680 stars and planetary systems in the ∼9′ beam of the telescope. All detections were either automatically rejected or visually inspected and confirmed to be of anthropogenic nature. We also quantified the end-to-end efficiency of radio SETI pipelines with a signal injection and recovery analysis. The UCLA SETI pipeline recovers 94.0% of the injected signals over the usable frequency range of the receiver and 98.7% of the injections when regions of dense radio frequency interference are excluded. In another pipeline that uses incoherent sums of 51 consecutive spectra, the recovery rate is ∼15 times smaller at ∼6%. The pipeline efficiency affects calculations of transmitter prevalence and SETI search volume. Accordingly, we developed an improved Drake figure of merit and a formalism to place upper limits on transmitter prevalence that take the pipeline efficiency and transmitter duty cycle into account. Based on our observations, we can state at the 95% confidence level that fewer than 6.6% of stars within 100 pc host a transmitter that is continuously transmitting a narrowband signal with an equivalent isotropic radiated power (EIRP) > 1013 W. For stars within 20,000 ly, the fraction of stars with detectable transmitters (EIRP > 5 × 1016 W) is at most 3 × 10−4. Finally, we showed that the UCLA SETI pipeline natively detects the signals detected with AI techniques by Ma et al.

300-GHz-Band Four-Element CMOS-InP Hybrid Phased-Array Transmitter With 36circ Steering Range

This letter presents a 300-GHz-band four-element phased-array transmitter (TX) consisting of two types of chips, CMOS and InP HBT, to achieve a high equivalent isotropically radiated power (EIRP) and wide beam coverage. The CMOS chips include mixers and control circuits for the phased-array operation and the InP HBT chips include 300-GHz-band power amplifiers (PAs) and Antipodal Vivaldi on-chip antennas. The two types of chips are connected in a flip-chip-on-chip fashion to reduce losses. A method utilizing grating lobes is devised to overcome the limited main lobe steering range. The fabricated TX achieves a maximum EIRP of 8.4 dBm with a steering range of 36 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\circ}$</tex-math> </inline-formula> , which is the widest among the 300-GHz-band TXs that can handle a high modulation order. The TX also demonstrates the first-ever wireless data transmission with beam steering in the 300-GHz band and achieves a maximum data rate of 30 Gb/s over a 50-cm distance.

A 16 × 16 45° Slant-Polarized Gapwaveguide Phased Array With 65-dBm EIRP at 28 GHz

A high equivalent isotropic radiated power (EIRP) active phased array antenna is proposed for fifth-generation (5G) communication systems at 28 GHz. The numerical design, measurements of a fabricated prototype, and performance analysis are presented. The antenna design is based on the gapwaveguide technology and consists of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$16 \times 16$ </tex-math></inline-formula> single 45° slant-polarized elements. The proposed design uses a low complexity printed circuit board (PCB) structure with only six layers, i.e., a half of the existing wideband solutions. The array antenna incorporates up/downconverter integrated circuits (UDCs) and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1 \times 4$ </tex-math></inline-formula> transceiver beamformer integrated circuits (BFICs). Moreover, a compact and highly efficient transition at the end of each channel of the BFICs has been designed to interconnect the antenna elements with the PCB. The antenna’s front-end loss, which includes the feed line, mismatch, and ohmic losses, is only 1.3 dB. The array covers the scanning range of ±60° in the azimuth plane and ±10° in the elevation plane. The <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$S_{11} &lt; -10$ </tex-math></inline-formula> dB frequency bandwidth is from 26.5 to 29.5 GHz. The maximum EIRP of the antenna is 65.5 dBm at saturation point. The presented design offers a compact, robust, and low-loss performance solution meeting the high transmission power requirements of 5G applications.

5G/mm-Wave Fully-Passive Dual Rotman Lens-Based Harmonic mmID for Long Range Microlocalization Over Wide Angular Ranges

In this work, for the first time, a 5G/mm-Wave harmonic frequency modulated continuous wave (FMCW) radar with dual Rotman lens-based harmonic millimeter identification (mmID) ranging system is proposed enabling ultralong range highly accurate localization for future localized sensing cyberphysical systems (CPSs). A detailed characterization of the fully-passive harmonic mmID is first presented with an estimated maximum harmonic radar cross section (RCS) of −35.8 dBsm and a 10 dB beamwidth of ±50°. The mmID fully overcomes the high-gain beamwidth tradeoff seen in typical high-gain designs enabling robust, ultralong-range detectability. A link budget analysis of the proposed harmonic mmID is presented with the current proof-of-concept (PoC) harmonic radar and with an equivalent isotropic radiated power (EIRP) of 75 dBm reading ranges in excess of 8 km are envisioned. In addition, the system provides a highly accurate ranging at long range with a bounded maximum ranging error of 17 cm up to 46 m from the radar. Furthermore, the 5G/mm-Wave system capitalizes on the highly sensitive phase information for ultrafine 0.4 mm accurate ranging at 10 m. Thus, the proposed system presents a fully-passive, long-range ranging system for future CPSs.

Scan-Loss Compensation for Full-Azimuth Multi-Facet Phased Array Antennas

An approach to compensate scan losses displayed by full-azimuth multifacet phased arrays is proposed in this article. This approach is based on a constructive superposition of scanned beams from adjacent array panels resulting in enhanced composed coverage. Said constructive superposition is achieved by coordinating the insertion phase shifts applied at the array element level. Special attention is given to panel arrays arranged in equilateral triangle and square prisms. The benefits of the proposed beamforming approach are validated by full-wave simulations, as well as passive antenna measurements taken on physical prototypes. The achieved improvement in equivalent isotropically radiated power (EIRP) excessively compensates for the experienced scan loss and reaches 6 dB at the maximal scan angles. An additional advantage of the developed methodology consists in the mitigation of the composed beam squint at wide scan angles.

Compact Green Harmonic Transponders for Parcel Tracking

This article presents a harmonic transponder, designed to minimize the tag sensitivity to the materials close to it. The tag is based on a dual-frequency dual-port patch antenna and a frequency doubler. The tag is designed to be interrogated by the fundamental frequency f0 equal to 2.4 GHz and it backscatters a signal at 2f0=4.8 GHz. The patch is realized on cardboard, while the frequency doubler and the feedlines are manufactured on a flexible polylactic acid (PLA) substrate. The feed lines are electromagnetically coupled to the patch through H slot apertures. A complete prototype with an area occupation of 5×10 cm was manufactured and directly integrated in a parcel. The antenna features a front-to-back ratio higher than 12 dB at both operating frequencies. The tag could be read up to a distance of 6 m with a transmitted power of 25 dBm Equivalent Isotropically Radiated Power (EIRP), regardless of the object placed in the parcel close to the tag. This work opens the door to a new class of harmonic transponders for tracking applications, characterized by low environmental impact, high integrability, compactness and reliability, which can find application in many Internet of Things emerging applications.

Interferometric Phase Transmitarray for Spatial Power Combining to Enhance EIRP of Millimeter-Wave Transmitters

An interferometric phase transmitarray is proposed for spatial power combining to enhance the equivalent isotropically radiated power (EIRP) of the millimeter-wave (mmW) transmitters. The study shows that the multiple beams emitting from the ideal point sources located at different positions are combined into one beam to radiate in the boresight direction of the transmitarray, namely, achieving spatial power combining. As an example, the prototyped transmitarray fed by two patch antennas operating over the bandwidth of 23–27 GHz shows that with the spatial power combining, the proposed antenna achieves the combined gain realized by two feeds of 19.6 dBi at boresight 2.5 dB higher than the realized gain of the single feed, so that the EIRP of the two-feed transmitarray is enhanced by 5.5 dB because of 2.5 dB from the gain enhancement of two-feed transmitarray and 3 dB by the two-way power combining.

Satellite Localization of IoT Devices Using Signal Strength and Doppler Measurements

Determining the location of wireless devices is vital in many applications. However, global navigation satellite system technologies require a dedicated hardware module installed in the device, imposing additional power and cost constraints. This letter presents a framework to passively localize ground wireless devices by a constellation of satellites using only the signal strength and Doppler measurements. We derive the likelihood of the measurements and then compare two methods: first by applying a stochastic optimizer, namely simulated annealing, and second using Markov Chain Monte Carlo (MCMC) algorithm to draw a sample distribution of the estimated location and the device Equivalent Isotropic Radiated Power (EIRP). Simulation results under realistic Internet-of-things scenarios show that reliable IoT device localization can be achieved using several satellites.

Design for Array-Fed Beam-Scanning Reflector Antennas With Maximum Radiated Power Efficiency Based on Near-Field Pattern Synthesis by Support Vector Machine

The maximum radiation efficiency can be obtained when the feed array excitation of a reflector antenna is synthesized by the conjugate field matching (CFM) method. However, the CFM method can only get the strongly tapered feeding power distribution. This will lead to most of power amplifiers (PAs) working in low efficiency states and reduce the equivalent isotropic radiated power (EIRP) with the limited power consumption. In this work, combining the radiation efficiency and the PA efficiency, the radiated power efficiency (RPE) is defined as the new design goal and is to be raised to achieve higher EIRP. For this reason, a method based on the near-field pattern synthesis is proposed. In this method, all the ON-state PAs are required to work in the highest efficiency state. Then, with well-trained support vector machine (SVM), the ON–OFF states of the PAs are adjusted so that the reflected focal field can be better synthesized by the near-field pattern of the feed array. Thus, the loss of the radiation efficiency is minimized. As a result, the RPE is about 22% higher than that of the CFM method and about 10% higher than that of the optimum CFM truncation case.

Highly Efficient Terahertz Beam-Steerable Integrated Radiator Based on Tunable Boundary Conditions

In this article, a highly efficient terahertz (THz) beam-steerable integrated radiator based on tunable boundary conditions is presented. The boundary conditions seen by the central slot radiator are tuned by the switched slots, and the corresponding radiation patterns can be altered. This technique enables a beam-steerable THz antenna with high radiation efficiency. In addition, the DC-THz efficiency of the harmonic voltage-control oscillator (VCO) is boosted through the 2-D harmonic boosting technique. Based on the two techniques above, the THz beam-steerable radiator has been implemented in a 130-nm SiGe BiCMOS process (<inline-formula> <tex-math notation="LaTeX">$f_{T}/f_{\mathrm {max}} =300$ </tex-math></inline-formula>/450 GHz). Without silicon lens, it achieves 60&#x00B0; scan ranges in the <inline-formula> <tex-math notation="LaTeX">$E$ </tex-math></inline-formula>-plane, an equivalent isotropic radiated power (EIRP) of 2.2 dBm, &#x2212;2.8 dBm radiation power, 0.91&#x0025; DC-THz efficiency, and the tuning range of 11.5&#x0025; for the supply of 1.7 V. With silicon lens, it achieves the EIRP of 21.66 dBm, 0.56-dBm radiation power, 2.22&#x0025; DC-THz efficiency, and tuning range of 10.8&#x0025; for the supply of 1.6 V. Among the silicon-based beam-steerable radiators over 300 GHz, it achieves state-of-the-art dc-to-THz efficiency.

A mm-Wave 5G System Architecture With Enhanced-Gain Antenna Solution

A millimeter-wave (mm-wave) system architecture with enhanced-gain antenna solution is proposed for fifth-generation (5G) wireless communications. To enhance the antenna gain, the surface wave currents are converted to constructive far-field radiations through a novel two-stage metallic and dielectric rings. By applying low-profile dielectric ring, the electric near-field distributions of the grounded quarter-wavelength metallic ring are modified to create radiation apertures with appropriate polarization and orientation. The mutual coupling between transmit/receive antennas and cross polarizations is reduced by 7 and 5 dB, respectively, and the gain is enhanced over 4 dB. Low-loss mm-wave transitions are implemented in a standard FR-4 printed circuit board and in an interposer substrate to integrate the active antenna with the rest of the wireless system on a compact universal serial bus (USB)-interface platform. To evaluate the interposer package and define the output power of the embedded 60-GHz RF IC, an evaluation module with a standard WR-15 waveguide interface is designed and implemented. A prototype of the architecture, which is entirely realized using low-cost organic substrates, is presented and evaluated by experiments. Excellent correlations are achieved between simulations and measurements, demonstrating more than 25 dBm of equivalent isotropically radiated power (EIRP) over the unlicensed 60-GHz frequency band.

A 28-GHz Phased-Array Relay Transceiver for 5G Network Using Vector-Summing Backscatter With 24-GHz Wireless Power and LO Transfer

This article introduces a wirelessly powered phased-array transceiver for fifth-generation (5G) relay systems. To realize the battery-less relay operation, 24-GHz wireless power transfer (WPT) is employed. This relay transceiver consists of the proposed vector-summing backscatter for Transmitter (Tx) and a passive phase-shifting self-heterodyne Receiver (Rx) with a rectifier for Rx and WPT. The receiver generates dc power from the 24-GHz WPT signal, which is also used as a local oscillator (LO) signal to down-convert the 28-GHz 5G modulated data to a 4-GHz IF. The vector-summing backscatter up-converts the 4-GHz IF signal to 28-GHz using a 24-GHz LO signal while working as a 360° phase shifter with a 7-bit resolution. Both transmitter and receiver operate only using the generated power from the 24-GHz WPT. The chip area of the eight-path transceiver is 1.8 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and the transceiver is mounted on a 32-element phased-array antenna board. This module generates 3.1-mW dc power from 6.7-mW/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> received power density at 24 GHz. The transmitter achieves a −2.2-dBm measured saturated equivalent isotropically radiated power (EIRP) and supports a −30° to +30° beam range. The measured error vector magnitude (EVM) values are −27.5 dB for Tx mode and −31.3 dB for Rx mode with a 400-MHz 64-QAM orthogonal frequency division multiple access (OFDMA)-mode signal (5G new radio (NR), MCS 19). The power consumption for each path is 0.03 mW in both Tx and Rx modes.

Harmonic Balance/Full-Wave Analysis of Wearable Harmonic Transponder for IoT Applications

The article presents a novel design of a compact wearable harmonic transponder with double-plane symmetry, composed of a dual-band patch-type antenna loaded by an HSMS-2820 Schottky diode, operated as a proof of concept at ISM UHF 869 and 1734 MHz frequencies. The antenna is analyzed and optimized for a minimum ground plate size by means of the CST Microwave Studio electromagnetic simulator, and its reflection coefficient is incorporated into the equivalent circuit model for a combined harmonic balance (HB) and full-wave analysis using the AWR Microwave Office commercial simulator. The transponder performance, including the complex input impedance matching and conversion loss (CL) between the fundamental and second harmonic frequencies on the diode, was evaluated both in free space and when attached to a human muscle phantom. The total harmonic transponder CL, including diode CL, antenna transponder gains, and impedance mismatching, is 6.2 dB for an excitation power of −25 dBm at the antenna–diode interface. The measured reading distances are 9.0 and 8.8 m for equivalent isotropically radiated power (EIRP) <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$=20$ </tex-math></inline-formula> dBm when the transponder is placed in free space and on the human body, respectively. As a means of machine-to-person communication, the transponder is suitable for the Internet of Things (IoT) concept, e.g., for the identification of pedestrians in traffic, i.e., in a complex environment with unwanted radiation clutter and multipath fading.

28 GHz circular polarized fan‐out antenna array with wide‐angle beam‐steering

The article presents 28 GHz circular polarized antenna arrays designed in an embedded wafer level ball grid array (eWLB) package for 5G applications. The antenna arrays are realized on a re-distribution layer (RDL) in the fan-out region of the chip package. Two separate but identical arrays perform RX and TX operations where a crossed dipole is used as a building block of the array. These 4-element arrays have <−10 dB impedance bandwidth covering 25.3–29.8 GHz (4.5 GHz bandwidth) while presenting 10 dBi maximum realized gain. The measurement results show <3 dB axial ratio in the band 26–29.5 GHz, and the main beam can be steered in ± 50 ∘ in the azimuth plane when array elements are fed by appropriate phases from the chip. The radio frequency module provides 31 dBm maximum equivalent isotropic radiated power (EIRP).

140–315 GHz spectrum measurement system and application to radiation pattern measurement

Considering the recent increase in the frequency of wireless communications, we have developed a spectrum measurement system in the 140–315 GHz range. The measurement system has a low spurious response by pre-selector over the whole band. For application, we measured radiation patterns emitted from a horn antenna, and the result shows that the measurement system is applicable to EIRP (equivalent isotropic radiated power) measurement of transmitters.

A New and Simple Design Method for End-Fire Dipole Antenna Array and Three Two-Element 24 GHz Planar End-Fire Dipole Antenna Arrays

For an RF system, a high-gain antenna helps to improve the equivalent isotropic radiated power (EIRP) of the transmitter and an end-fire antenna array helps to improve the directivity (D) and half power beam width (HP) of the antenna. This work presents a new and simple design method for end-fire antenna array design. The method states that when antenna elements are λ/2 apart, a simple end-fire antenna array could be designed and constructed easily without matching networks between antenna elements. Utilizing Rogers 4350 PCB technology, three 24 GHz high-gain, compact planar two-element end-fire dipole antenna arrays are designed to verify this new design method. The achieved results are three two-element end-fire antennas with gains of 8.8, 9.9 and 9.1 dBi. These antenna arrays are characterized by high gain and simplicity in design. They are also very compact in size, with an area of about 1.9 × 1.7 cm2. The benefit of this work is that a new and simple design for end-fire antenna design is suggested, and three two-element end-fire dipole antenna arrays in planar technology which adopt the design method are presented. A utility model patent was granted for this end-fire dipole array antenna topology, ZL 202022106332.1.

Fast Double-Directional Full Azimuth Sweep Channel Sounder Using Low-Cost COTS Beamforming RF Transceivers

This paper presents a multipath component (MPC) parameter estimator that uses a double-directional (D-D) channel sounding system in WiGig millimeter-wave bands. It employs low-cost commercial-off-the-shelf (COTS) RF transceivers capable of beam steering within an azimuth angle range of ±45°; the transmit power is approximately 31 dBm, equivalent isotropic radiated power (EIRP), including a total antenna gain of approximately 19 dBi. The half-power beam widths in the azimuth and elevation planes are 6° and 45°, respectively. A fast D-D channel acquisition in 360° full azimuth range can be achieved by developing a 4 ×4 multiple-input-multiple-output (MIMO) time division-multiplexing (TDM) scheme that enables simultaneous use of four antenna arrays at both sides of the transmitter and receiver. The beam switching for all combinations ( 48 ×48 = 2304) with 12 beams at each array requires less than 200 ms, excluding optional procedure related to data storage. A high-resolution MPC extraction method was developed from the D-D angular delay power spectra obtained using the sub-grid CLEAN algorithm, which is applicable when phase coherence among multiple snapshots obtained via the beam-switching measurement cannot be guaranteed. Furthermore, the operation of the developed system was validated via a measurement at 58.32 GHz in an office floor of a university laboratory. From the data analysis, the cluster properties and the corresponding scattering processes were identified.