Transmission Gain Research Articles

Radiation response of SiGe low noise amplifier irradiated with different energy protons

This research, for the first time, uses different energy protons of 5 MeV and 10 MeV to irradiate low noise amplifiers (LNAs) with a frequency band ranging from 1.4GHz to 1.8 GHz designed with 0.25 μm SiGe BiCMOS technology. It studies the resulting radiation effects and also compares the RF responses of the LNAs under different energy proton irradiations. The irradiation fluences of the two different protons are up to 1 × 1015 protons/cm2. The response characteristics of input reflection coefficient S11, transmission gain S21 and noise figure (NF) of the device RF performance before and after the 5 MeV and 10 MeV proton irradiations are compared and discussed. The results show that the input reflection coefficient decreases after the proton irradiations, and at 5 MeV, the transmission gain decreases by 1.8 dB at most, and the NF increases by 1.5 dB at most. Moreover, the degradation of LNA characteristic parameters under 5 MeV proton irradiation is much more than under 10 MeV proton irradiation, with the irradiation dose of 1 × 1015 protons/cm2.

소형화된 Ka 대역 송수신모듈 설계 및 제작

In this study, we propose a miniaturized Ka-band transceiver module with a microstrip-to-waveguide transition structure that can be applied to high-capacity wireless radio. We apply a probe-shaped transition structure with the vertical structure of a substrate and waveguide that can mount a filter on top of a transceiver module. Measurement results of the fabricated transition structure revealed an insertion loss of 0.67 dB or less and a return loss of −14.1dB or more in the frequency range of 28～30 GHz. Measurement results of the transceiver module when the transition structure was applied revealed a maximum output of 2 W, a transmission gain of 35 dB, a gain of 20 dB, and a return-loss performance of less than −10 dB.

Investigation of e-textile dipole antenna performance based on embroidery parameters

E-textile antennas have the potential to be the premier on-body wearable sensor. Embroidery techniques, which can be applied to produce e-textile antennas, assist in large production volumes and fast production speeds. This paper focuses on the effects of three commonly used embroidery parameters, namely stitch type, conductive thread location, and stabilizer, on the performance of embroidered dipole antennas in order to determine the ideal embroidery combination for optimal antenna performance. Fifty-four dipole antenna samples were fabricated and measured at the industrial, scientific, and medical (ISM) frequency band of 2.45 GHz. The results of this study show that machine-embroidered antenna designs with satin stitches resonate at a lower frequency and exhibit a lower transmission gain compared with those made with contour stiches, and the conductive thread location in the bobbin location plus the use of a water-soluble stabilizer can help improve impedance matching.

Effect of pitch on gain-noise figure and crosstalk performance of different core structure Multicore Erbium-Doped Fiber Amplifier: A comparative analysis

A detailed analysis of 7-cores Erbium-Doped Fiber Amplifier has been done to assess the effect of different core and pitch arrangement on the fiber amplifier's performance. The investigation is performed within the C-band communication wavelengths to compare the performance of Y-structure, T-structure, circular and linear structure of the core. The comparison is also extended further by including the performance of a widely used hexagonal structure. A thorough analysis is conducted by examining the profiles of gain, noise figure, and mode of transmission. The inter-core crosstalk (IC-XT) is also calculated for all the core structures and pitch, making this research effort conclusive. Maximum gain has been observed for the Y-shape/structure core arrangement, whereas minimum IC-XT has been observed for the hexagonal structure. However, an encouraging observation is that the percentage decrease in crosstalk due to an increase in pitch is significantly higher for Y-structure than hexagonal. Therefore, the authors believe that this detailed investigation gives significant insight to design efficient multicore EDFA in current research and development.

Index Modulation Based Coordinate Interleaved Orthogonal Design for Secure Communications

In this paper, we propose a physical layer security scheme that exploits a novel index modulation (IM) technique for coordinate interleaved orthogonal designs (CIOD). Utilizing the diversity gain of CIOD transmission, the proposed scheme, named CIOD-IM, provides an improved spectral efficiency by means of IM. In order to provide a satisfactory secrecy rate, we design a particular artificial noise matrix, which does not affect the performance of the legitimate receiver, while deteriorating the performance of the eavesdropper. We derive expressions of the ergodic secrecy rate and the theoretical bit error rate upper bound. In addition, we analyze the case of imperfect channel estimation by taking practical concerns into consideration. It is shown via computer simulations that the proposed scheme outperforms the existing IM-based schemes and might be a candidate for future secure communication systems.

Reliability evaluation and redesign methodology for RFCMOS transceiver frontend circuits in sub‐6‐GHz band of fifth‐generation new radio communication based on the reliability model

SummaryA proposed RFCMOS reliability subcircuit model to evaluate the transceiver frontend circuits for 5G new radio (NR) networks sub‐6‐GHz application is presented. When studied 1‐year operational performance considering hot‐carrier stress in circuit level, the common‐source LNA circuit is robust in gain and noise figure than common‐gate common‐source LNA circuit, and Class‐A power amplifier loses gain 52%. However, in transceiver system level, the receiver‐used two‐stage common‐gate common‐source LNA shows robust than used common‐source LNA. The transmitter's gain and output power exhibit a strong relationship with performance of Class‐A power amplifier after hot‐carrier stress. When the receiver using the overdriven bias 3.1 V 1 year predicted by proposed model, the EIS is −89.7 dBm, which still meet 5G FR1 standard though the gain degraded to 17 dB; transmitter overdriven at bias 3.3 V, the least output power is 19.1 dBm, which still meet 5G FR1 standard, though the IIP3 worsen to 13%.

Analysis of double‐Xi‐shaped millimetre‐wave patch antenna backed by a high‐order‐mode cavity using characteristic mode design

The authors propose an innovative double-Xi-shaped Chinese character artistic antenna backed by a high-order-mode cavity for 5G millimetre-wave (mm-wave) applications. The initial double-Xi-shaped microstrip antenna element is designed by using characteristic mode theory, and stable gain can be obtained across the whole 5G mm-wave frequency band. By employing a slotted cavity with TE230 high-order-mode to excite 2×2 antenna subarray, a high gain of 13.2 ± 0.8 dBi and a high isolation better than 45 dB without additional feeding networks can be simultaneously achieved. To further improve the gain for reliable transmission, a 4×4 dual linearly polarised (LP) antenna array is also designed and fabricated. Measured results show that a wide frequency bandwidth of 11.45% (24.7–27.7 GHz) with a peak gain of 19.2 dBi and a high isolation of 33 dB is realised for the dual LP antenna array. The proposed method provides a simple and efficient prediction-theory way to design artistic antenna for the first time, which solves the problem of designing specific-shaped antenna without theoretical support.

Programmable nonreciprocal meta-prism

Optical prisms are made of glass and map temporal frequencies into spatial frequencies by decomposing incident white light into its constituent colors and refract them into different directions. Conventional prisms suffer from their volumetric bulky and heavy structure and their material parameters are dictated by the Lorentz reciprocity theorem. Considering various applications of prisms in wave engineering and their growing applications in the invisible spectrum and antenna applications, there is a demand for compact apparatuses that are capable of providing prism functionality in a reconfigurable manner, with a nonreciprocal/reciprocal response. Here, we propose a nonreciprocal metasurface-based prism constituted of an array of phase- and amplitude-gradient frequency-dependent spatially variant radiating super-cells. In conventional optical prisms, nonreciprocal devices and metamaterials, the spatial decomposition and nonreciprocity functions are fixed and noneditable. Here, we present a programmable metasurface integrated with amplifiers to realize controllable nonreciprocal spatial decomposition, where each frequency component of the incident polychromatic wave can be transmitted under an arbitrary and programmable angle of transmission with a desired transmission gain. Such a polychromatic metasurface prism is constituted of frequency-dependent spatially variant transistor-based phase shifters and amplifiers for the spatial decomposition of the wave components. Interesting features include three-dimensional prism functionality with programmable angles of refraction, power amplification, and directive and diverse radiation beams. Furthermore, the metasurface prism can be digitally controlled via a field- programmable gate array (FPGA), making the metasurface a suitable solution for radars, holography applications, and wireless telecommunication systems.

An Analysis of RF On-Chip Antennas in Si-Based Integrated Microwave Photonics

We investigate the monolithic integration of RF antennas onto a silicon-based integrated microwave photonics (IMWP) chip for short-range millimeter-wave (mmW) communication. The unification of antenna with photonic integrated circuits (PICs) reduces system loss for high data rate communication by eliminating parasitic interconnects. This integration of electronics (antenna) with photonics will be a key milestone leading to increased bandwidth capability and ubiquitous wireless links for emerging applications such as 5G, Internet of Things (IoT), autonomous vehicles, high data rate point-to-point communication, and wireless sensors. Through simulation above 20 GHz, we compare the transmission of three on-chip antenna structures designed in a commercial silicon photonics (SiPh) process and consider them for both inter and intra-chip communication. Results provide insight on the transmission gain variations relative to the antenna orientation from their distinct radiation pattern. The folded monopole structure provides superior gain, smaller footprint with layout flexibility, and good transmission spectrum. The analysis supports the idea of a monolithic mmW transmitter integrated with on-chip antennas on IMWP chip.

Performance Analysis of Data Transmission for Joint Radar and Communication Systems

This paper investigates the problem of data transmission for the joint radar and communication systems (JRCSs). The performance of the JRCS is characterized by data throughput related to the radar echo data (RED) and communication data rate (CDR). Two spectral coexistence schemes are proposed based on the degree of spectrum sharing for radar and communication, i.e., the isolated subfrequency band (ISFB) and mix-used frequency band (MUFB) schemes. Firstly, the signals of radar and communication are operated on the isolated subcarriers, enabling the received signals to be processed independently and bringing the advantage of interference avoidance. Secondly, the signals of radar and communication can be jointly operated on the same subcarriers for the MUFB scheme, which enhances the spectrum efficiency. Unlike the ISFB scheme, the CDR of the MUFB scheme is maximized along with the interference from the radar signal, and meanwhile, the allocated radar power on each subcarrier is derived by maximizing the radar mutual information. Numerical results show that the MUFB scheme significantly improves the performance of data transmission over the ISFB scheme, and a significant performance gain in the data transmission can be achieved, compared to the average power allocation case.

A Parametric Study of Inductive SWIPT Systems Assisted by Metamaterial Using Virtual Magnetic TL-Based Channel Modeling

Abstract This paper presents a general methodology based on the description of the inductive channel as virtual magnetic transmission-lines (VMGTLs). In comparison with other existing methods, VMGTL approach presents a better physical insight of the channel behavior since the model correctly preserves the energy flow between the transmitting and receiving coils. Besides that, it facilitates the integration into the analysis of highly nonlinear and dispersive structures such as metamaterial (MTM) lenses. Particularly, the virtual-TL analogy clarifies that the enhancement of the transmission gain between any two coils assisted by MTM is not due to an enhanced coupling between the drivers, as usually claimed, but to the emergence of propagating near-field modes supported by the MTM. This approach, by means of a parametric study, also indicates, for the first time, that MTMs could be employed not only for the increasing of power but also of data transfer due to the emergence of a sub-resonant region of minimum distortion. Nonetheless, since both effects are mutually exclusive, no passive MTM structure could simultaneously improve power and data transmission.

An anti-noise transmission algorithm for 5G mobile data based on constellation selection and channel joint mapping

The current transmission algorithms for fifth generation (5G) mobile data fail to consider the mapping between signal pre-transmission and channel encryption, making it difficult to eliminate Rice noise, improve data transmission, or ensure the quality of source transmission. To solve the problem, this paper proposes an anti-noise transmission algorithm for 5G mobile data based on constellation optimization and channel joint mapping. Firstly, a constellation optimization mechanism was established based on projection signal. The mechanism eliminates the projection vector of signal error, and improves the signal transmission gain. Then, the performance of anti-fading channel was optimized by the sequence weight rearrangement (SWR) mechanism, and the energy attenuation was assessed by the quantitative evaluation model of the source segmentation mapping transmission (SSMT) mechanism. In this way, the Rice noise can be effectively removed from the channel, and the occurrence of channel error can be greatly reduced. Through NS2 simulation, the proposed method was proved to be superior to High Density Orthogonal Channel with Encryption (HDOCE) Algorithm, which is widely used in high density 5G orthogonal channels, and Optimized Transmission Encryption algorithm based on Concurrent Channel Segmentation (OTE_CCS) in transmission error, signal strength, and source transmission quality.

Social media effectiveness as a humanitarian response to mitigate influenza epidemic and COVID-19 pandemic.

Influenza and COVID-19 are infectious diseases with significant burdens. Information and awareness on preventative techniques can be spread through the use of social media, which has become an increasingly utilized tool in recent years. This study developed a dynamic transmission model to investigate the impact of social media, particularly tweets via the social networking platform, Twitter on the number of influenza and COVID-19 cases of infection and deaths. We modified the traditional Susceptible-Exposed-Infectious-Recovered (SEIR-V) model with an additional social media component, in order to increase the accuracy of transmission dynamics and gain insight on whether social media is a beneficial behavioral intervention for these infectious diseases. The analysis found that social media has a positive effect in mitigating the spread of contagious disease in terms of peak time, peak magnitude, total infected, and total death; and the results also showed that social media’s effect has a non-linear relationship with the reproduction number {R}_{0} and it will be amplified when a vaccine is available. The findings indicate that social media is an integral part in the humanitarian logistics of pandemic and emergency preparedness, and contributes to the literature by informing best practices in the response to similar disasters.

Prefrontal α7nAChR Signaling Differentially Modulates Afferent Drive and Trace Fear Conditioning Behavior in Adolescent and Adult Rats.

Increased level of kynurenic acid is thought to contribute to the development of cognitive deficits in schizophrenia through an α7nAChR-mediated mechanism in the prefrontal cortex (PFC). However, it remains unclear to what extent disruption of PFC α7nAChR signaling impacts afferent transmission and its modulation of behavior. Using male rats, we found that PFC infusion of methyllycaconitine (MLA; α7nAChR antagonist) shifts ventral hippocampal-induced local field potential (LFP) suppression to LFP facilitation, an effect only observed in adults. Hippocampal stimulation can also elicit a GluN2B-mediated LFP potentiation (when PFC GABAAR is blocked) that is insensitive to MLA. Conversely, PFC infusion of MLA diminished the gain of amygdalar transmission, which is already enabled by postnatal day (P)30. Behaviorally, the impact of prefrontal MLA on trace fear-conditioning and extinction was also age related. While freezing behavior during conditioning was reduced by MLA only in adults, it elicited opposite effects in adolescent and adult rats during extinction as revealed by the level of reduced and increased freezing response, respectively. We next asked whether the late-adolescent onset of α7nAChR modulation of hippocampal inputs contributes to the age-dependent effect of MLA during extinction. Data revealed that the increased freezing behavior elicited by MLA in adult rats could be driven by a dysregulation of the GluN2B transmission in the PFC. Collectively, these results indicate that distinct neural circuits are recruited during the extinction of trace fear memory in adolescents and adults, likely because of the late-adolescent maturation of the ventral hippocampal-PFC functional connectivity and its modulation by α7nAChR signaling.SIGNIFICANCE STATEMENT Abnormal elevation of the astrocyte-derived metabolite kynurenic acid in the prefrontal cortex (PFC) is thought to impair cognitive functions in schizophrenia through an α7nAChR-mediated mechanism. Here, we found that prefrontal α7nAChR signaling is recruited to control the gain of hippocampal and amygdalar afferent transmission in an input-specific, age-related manner during the adolescent transition to adulthood. Behaviorally, prefrontal α7nAChR modulation of trace fear memory was also age-related, likely because of the late-adolescent maturation of the ventral hippocampal pathway and its recruitment of PFC GABAergic transmission enabled by local α7nAChR signaling. Collectively, these results reveal that distinct α7nAChR-sensitive neural circuits contribute to regulate behavior responses in adolescents and adults, particularly those requiring proper integration of hippocampal and amygdalar inputs by the PFC.

Analytical Performance Assessment of Beamforming Efficiency in Reconfigurable Intelligent Surface-Aided Links

Future wireless networks designed to operate in the millimeter-wave and terahertz bands are expected to be highly assisted by Reconfigurable Intelligent Surfaces (RIS). The role of the RIS will be to mediate possible non-line-of-sight link by redirecting the incident beam from the transmitter to the receiver and possibly modifying its characteristics, in order to optimize the beamforming efficiency and to maximize the signal power at the receiver. Therefore, it is crucial to understand what are the bounds imposed on the received power and how these bounds depend on the system design parameters. In this paper we show that, contrary to typical line-of-sight links, the increase of the transmitter gain does not always guarantee power increase at the receiver, even for an infinitely large RIS, and we explain how the RIS size can further affect the received power. We present an analytical model that captures the performance of the RIS-aided link in the limit of very large RIS, and we demonstrate numerical examples that provide insight on the interplay between the RIS size and the properties of the transmitter beam.

An Optimization Method for Simultaneous Wireless Power and Data Transfer Systems

Simultaneous wireless power and data transfer (SWPDT) technology is usually needed in wireless power transfer (WPT) systems. In this paper, to achieve the efficient and stable SWPDT, the signal to noise rate (SNR) is first optimized through the analysis of data transmission gain and the interference of power transfer on data transfer. In order to reduce the interference of power channel to data transfer channel, the compensation topology of double-sided LCC and the band-stop networks are used. To solve the problem of SNR limitation, the coupling relationships between each circuit are taken into consideration and a matching method of resonance parameters to improve the SNR is presented. Based on the relationship between SNR and the parameters of data transfer channel, an optimization design method focused on parameters of data transfer channel for improving the SNR is presented. Finally, the feasibility and the correctness of the parameter design method proposed in this paper is verified by simulation and experiment.

A 4.4-mA ESD-Safe 900-MHz LNA With 0.9-dB Noise Figure

A 900-MHz 1.2-V 4.36-mA low-noise amplifier (LNA) with a minimum of 0.92-dB noise figure (NF) at 868 MHz, -12-dBm IIP3, with one inductor (external) is demonstrated. The circuit achieves narrowband input matching on a wideband LNA without inductive degeneration. A new half-cascoding technique is used to improve the input matching (S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> ) while simultaneously achieving sub-1-dB NF performance. The 0.13-μm CMOS LNA is fabricated with embedded electrostatic discharge (ESD) protection diodes that add 60 and 80-fF loads at the RF input and output ports. At 868 MHz, the packaged LNA has a measured input return loss (S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> ) of -18 dB and the transmission gain (S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</sub> ) of 14.2 dB. At 900 MHz, the LNA has a measured NF of 0.98 dB. The LNA (excluding the buffer) occupies an area of 0.047 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The chip passes the human body model (HBM) test with an ESD zap of 2.5 kV within 10% margin of its prezap I-V characteristics, under JEDEC standards. Multiple packaged chips were characterized with no perceptible difference in performance, indicating a robust design.

ArF laser-induced damage of calcium fluoride windows with protected anti-reflection coatings

High-power ArF lasers for high-volume production of mobile consumer microelectronics demand low loss and laser durable calcium fluoride (CaF2) laser-windows. Increased laser durability is realized by F-SiO2 protective coatings on CaF2 windows with subsurface-damage-free (SSD-free) surface finishing. Surface reflection loss is reduced by fluoride-based anti-reflection (AR) coatings. In this contribution, we integrated the protective coating with the fluoride-based AR coatings on SSD-free CaF2 windows and assessed the laser damage resistance of the window using an ArF laser with a pulse length of 20 ns and a rep rate of 20 Hz. Damage initiation sites were detected on the entrance surface at a fluence of 3.5 J / cm2. A 100% damage probability was determined at a fluence of 5 J / cm2. An absorption-driven thermal damage mechanism was indicated by the damage morphology. Similar laser damage resistance was realized on the protected AR-coated windows with more than 9% transmission gain when compared to that of the F-SiO2 protected CaF2 laser-windows. The results suggest that two-photon absorption is a dominant factor when nonlinear absorption occurs in the laser-irradiated CaF2 windows. The thermally induced damage could be further simulated using the experimentally determined two-photon absorption coefficient based on the ArF laser calorimetry technique.

Noise effect on the signal transmission in an underdamped fractional coupled system

The signal transmission phenomenon in an underdamped fractional system composed of two harmonically coupled particles, but only the first particle, which is driven by a periodic force, is studied. We obtain the analytical expressions for the steady-state response of the two coupled particles by applying the stochastic averaging method and define the signal transmission factor to characterize signal transmission efficiency. We analyze the impact of noise on signal transmission efficiency and provide the discriminant criterion for the emergence of the signal transmission enhancement phenomenon. We also analyze the resonance behavior of the signal transmission factor and provide the discriminant criterion for the emergence of different types of resonance behavior based on system parameters. We draw the phase diagrams for varying resonance behavior versus different parameters and study the influences of the parameters on resonance behavior. It is found that the coupling strength and fractional-order exert important influences on the signal transmission efficiency and resonance behavior, and the fractional coupled system exhibits complicated dynamic behaviors than the integer coupled system. Lastly, numerical simulations for the signal transmission factor $$\eta $$ , and the output signal-to-noise ratio (SNR) transmission gain $$\text {SNR}_{\eta }$$ are performed. We can control signal transmission efficiency and resonance behavior within a certain range by understanding the effects of system parameters on the underdamped fractional coupled system, and it has potential applications in modern science.

60 GHz wide‐band psi (Ψ)‐shaped long‐wire antenna for wireless on‐board chip‐to‐multi‐chip communication

A novel type of wide-band long-wire antenna is presented for 60 GHz wireless on-board chip-to-multi-chip applications using a vertically polarised electric field. The psi-shaped structure is devised to match the antenna input impedance to 50 Ω and to increase the front-to-back ratio by placing two bent 0.5λeff lines parallel to the original long-wire antenna, which resulted in improved realised gain and can be directivity compared to those of a conventional baseline structure. The psi-shaped long-wire antenna shows a peak gain of 10.2 dBi, an end-fire gain of 7 dBi, a 22% impedance bandwidth (52–65.2 GHz), and a 25.8% 3 dB gain bandwidth (56–74 GHz) in an area of 3.1 × 105 mm2. This study presents the proposed antenna for an on-board chip-to-multi-chip communication scenario for a distance of 20 mm, with a peak transmission gain of −19.5 dB and a 3 dB bandwidth of 11.8 GHz (=19.6%), which ranges from 55.4 to 67.2 GHz.