Transmitter Output Power Research Articles

A fully-integrated 60-GHz 8-element phased-array transceiver with embedded antenna T/R switch in 65-nm CMOS

This paper presents an 8-element phased-array heterodyne transceiver (TRX) chip for 60-GHz wireless applications. The chip integrates transmit/receive (T/R) elements, bi-directional variable-gain driving amplifiers (BI-VGDAs), up/down mixing chains, and the local oscillator (LO) chain. To support the time division duplexing (TDD) operation and increase output power, a low-loss compact on-chip antenna T/R switch is introduced by embedding it in the power amplifier (PA) power combiner, thereby achieving a high transmitter (TX) output power and low receiver (RX) noise figure (NF), respectively. Fabricated in a 65-nm CMOS process, the proposed phased array TRX chip occupies an area of 5.1 mm × 2.5 mm. With measurements, the TX path provides a 32-dB maximum conversion gain, an 11.3-dBm OP1dB, and a 16-dBm Psat, respectively. The RX path achieves a peak gain of 24 dB and an NF of 6.5–9 dB across 57–66 GHz. With the 16-QAM modulation, a 7.04 Gb/s data rate is demonstrated.

The wireless communications systems in subterahertz frequency range

Background. The subterahertz and terahertz frequency ranges are very promising for development of high speed wireless communications systems because of possibility to get the bandwidth about some tens of GHz, which provides the high channel capacity. However fast signal attenuation at its propagation in atmosphere complicate the operation of communications systems in these ranges.
 Aim. Use of fixed narrow-beam antennas with high antenna power gain allows to provide the direct surface communications distance to some kilometers. The communications distance limitation can be partially removed decreasing the frequency down to 200 GHz and narrowing the channel bandwidth down to some GHz.
 Methods.The model of transmitter-receiver system (200-220 GHz) based of modern semiconductor devices is described in the manuscript. Results. The possibility of digital signals transmission with speed up to 1 Gbit/s at the distance of 1 km is experimentally shown.
 Conclusion. According to calculations the output power of transmitter about some hundreds mW is enough for data transmission at the distance up to 1.5 km with antenna power gain of no less than 50 dB.

A Low-Power V-Band Radar Transceiver Front-End Chip Using 1.5 V Supply in 130-nm SiGe BiCMOS

Energy-efficient, low-voltage, and low-power millimeter-wave (mm-wave) radars are gaining increasing attention for battery-powered commercial applications. In this article, the design of a low-power <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> -band radar sensor based on a transceiver (TRX) front-end chip using 1.5 V supply in an advanced SiGe BiCMOS technology with 300 GHz <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit{f}\textsubscript{T}$</tex-math> </inline-formula> and 500 GHz <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit{f}\textsubscript{max}$</tex-math> </inline-formula> is presented. The monostatic front-end chip utilizes low-voltage low-power circuit-level design techniques to achieve measured 9-dBm transmitter (TX) output power and 27-dB receiver (RX) gain with a simulated 3.8-dB noise figure (NF) consuming a total of only 72 mW in continuous mode. The TRX chip is used to build a radar sensor, which is experimentally verified in an anechoic chamber. The low-power sensor achieves a 46-dB dynamic range and a ranging precision better than 3.4 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu$</tex-math> </inline-formula> m measured with a static target at 1 m. Phase measurements using the low-power radar in the continuous-wave (CW) mode demonstrate that submillimeter movements can be tracked, and notably main vital parameters of a human can be determined accurately. Experimental results show that the performance of the proposed low-power TRX front-end chip is very competitive with designs in modern CMOS technologies.

Automatic RF Leakage Cancellation for Improved Remote Vital Sign Detection Using a Low-IF Dual-PLL Radar System

Remote vital sign detection using Doppler radar has gained increasing interest over the years. However, challenges remain in improving radar system sensitivity to extend the detection range. In this article, we analyze noise contributions in a dual-PLL low-IF Doppler radar system and identify RF leakage/coupling as a major component of the system noise floor. This effect results in negligible SNR improvement when the transmit output power is increased beyond a certain threshold. By applying RF leakage/coupling cancellation through phase and magnitude adjustments, we demonstrate significant improvements to radar system performance. Furthermore, we propose and validate an automatic RF leakage cancellation scheme. The proposed technique is shown to achieve a vital-sign-sensing range of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4$</tex-math> </inline-formula> m under a very low transmit power of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$-$</tex-math> </inline-formula> 31 dBm and with a high confidence level of three beats per minute against the ground truth measured by an oximeter sensor.

An Economical DWPT System With Mutual Compensation of Segmented Power Supply Rails Based on LCL Topology

For high-power, long-mileage dynamic wireless power transfer (DWPT) system, its economy and adaptability to complex working conditions are the main factors limiting its popularization and application. In this paper, the compensation and power supply of segmented rails are studied, and a DWPT system with mutual compensation of segmented power supply rails based on LCL topology is constructed. By multiplexing components, the number, cost and volume of devices are reduced, and the economy of the system is improved. The power supply topology is optimized to achieve constant-current characteristics over a wide load range to generate a stable high-frequency magnetic field in space and avoid short-circuit current induced by mutual coupling of adjacent rail. The resonant control conditions of the system are derived, and a phase shift control method based on the three-leg inverter is proposed to realize the full range regulation of transmitter current and output power, and improve the adaptability of the system. The characteristics of the proposed DWPT system have been verified by an experimental prototype.

NSGA-III Based Heterogeneous Transmission Range Selection for Node Deployment in IEEE 802.15.4 Infrastructure for Sugarcane and Rice Crop Monitoring in a Humid Sub-Tropical Region

In this proposal, the impact of dynamic farm environment due to varying vegetation density on the Received Signal Strength (RSS), coverage and energy consumption of an IoT assisted Wireless Sensor Network (IoWSN) is analyzed through measurement campaign. Experimental observations on free-space and tree Path Loss Model (PLM) based sensor node deployment strategies in a cropping period have shown network disconnectivity due to incorrect assessment of excess attenuation caused by dynamically varying vegetation height and density during the monitoring period. To address the challenge, an empirically formulated PLM is proposed to estimate the excess attenuation at different crop development stages of medium grass vegetation. Further, using the formulated PLM, a Non-dominated Sorting Genetic Algorithm (NSGA-III) multi-objective optimization is performed to generate initial node deployment with a heterogeneous transmission range. To address the issue of over-coverage, transmitter output power scheduling is performed with predefined upper limit derived from the NSGA-III optimization. The output power is dynamically scheduled during the monitoring period based on changes in the captured RSS to minimize over-coverage. Improvements in coverage, connectivity, and energy efficiency compared to existing approaches are validated through Proof of Concept.

Plasmonic biosensor based on metal antenna on graphene for detection and counting of nanoparticles

Plasmons in graphene present desirable electronic properties and unique opportunities to enhance light–matter interactions and control light at nanoscale dimensions. The combination of graphene with metal nanostructures is promising for optical science and plasmonic manipulations. We propose a graphene plasmonic system based on a resonant metal antenna for detection and counting of nanoparticles. The performance of the proposed system relies on the intrinsic properties of particles, including the refractive index, which can be used to modulate the transmitted power. Simulations show that, by a small change in the refractive index of the particle, the transmitted output power changes significantly. A local change of ±10% in the refractive index of a 50-nm dielectric particle around the nanopore results in a ∓2.3% variation in the transmitted power corresponding to a sensor sensitivity of 415 nm/RIU. Small particles with a diameter of 20 ​nm can be detected using this configuration. The placement of a nanopore and nanoparticle in front of the metal antenna can change the spatial near-filed distribution of graphene plasmons and control their propagation wavefronts. Furthermore, the proposed structure with its small footprint can be readily integrated into lab-on-a-chip devices for practical biosensing applications. This plasmonic device is promising for use in single-particle detection and biological applications.

Universal wavelength reuse mechanism for optical networks-on-chip based on a cooperative game

Optical networks-on-chip (ONoCs) based on wavelength division multiplexing (WDM) technology have lower end-to-end (ETE) delay, larger bandwidth, and higher throughput than NoCs. However, the utilization and parallelism of individual wavelengths are essential since WDM technology would require more optical devices to be integrated with ONoCs, leading to higher on-chip overhead. In this paper, we propose an optimal model of communication node cooperation based on game theory, in which the loss of the optical signal on the transmission path for a specific optical receiver sensitivity establishes the payoff function of each participant. In this cooperative game model, the communication nodes are regarded as the participants of the cooperative game. By analyzing the principle of optical router port occupation, the coordinate-based coalition assignment algorithm is proposed to implement fast construction of coalitions and reach the Nash equilibrium of the cooperative game. In Nash equilibrium, the utilization and parallelism of individual wavelengths are higher, and the network’s performance is optimized and improved. Cooperative-game-based ONoCs have more significant throughput and lower ETE delay. The optical signal loss and minimum output power of the optical transmitter can be further reduced at a given optical receiver sensitivity. By applying the cooperative game to ONoCs, the network’s optimization effect becomes more evident as the network scale increases and the number of communication nodes grows.

Low Frequency Terahertz Induced Thermoacoustic Signal Characteristics and Its Application in Solid-State Terahertz Transmitter Power Detection

According to the 2019 Federal Communications Commission (FCC) standard, the spectrum range of 6G is 95 GHz to 3 THz. Due to the higher density of 6G base station, a portable, low-cost, and real-time power detection method for transmitters is urgently needed. Therefore, we propose a real-time terahertz (THz) power detection method based on terahertz-thermoacoustic (THz-TA) effect. Using a homemade solid-state THz transmitter (center frequency = 170 GHz, maximum output power = 92.8 mW), we investigate the relationship between THz power, pulsewidth, and THz induced thermoacoustic signal, respectively. Compared with the test results of commercial THz power meter (Erickson-PM5), the feasibility of THz power detection based on THz-TA effect is proved. The experimental results show that the minimum THz power that THz-TA test platform can respond to is 2.8 mW, and the response time is about 0.25 seconds. In the range of 2.8 −92.8 mW, the amplitude of THz-induced TA signal is linear with the output power of solid-state THz transmitter (Pearson's <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</i> = 0.99571). We also note for the first time that the time interval of THz-induced TA signal is consistent with the pulsewidth of THz signal (0.5, 1, 2, and 5 μs). Therefore, THz-TA technology can not only realize the real-time detection of THz power but also measure the pulsewidth of amplitude-modulated THz signal to a certain extent. We expect that THz-TA detection method will have great potential in the real-time detection of transmitter power of 6G base station in the future.

Design and performance analysis of smart photonic sensors for industrial applications

Toxic gas has a median fatal concentration in the oxygen of much more than 200 parts per million (ppm) but far less than 2000 ppm by volume of gas. Many industries, mines and thermal plants emit perilous gases that are more harmful to our human life. The Proposed nanosensor senses the various perilous gases and averts many accidents. In this paper, a two-dimensional Photonic Crystal (2D-PhC) resonator and PhC-based poisonous gas sensor based on the hexagonal and square crystal lattice are built-in smart way. The PhCs are artificial constructs of any material with an occasional enunciation of refractive index (RI). It has effective light manipulation and it would be helpful to obtain light migration in the handling of sensing applications. The TE/TM wave transmission can shift as per the RI value of different gases in the PhCs. The wavelength variations obtained agree well with the Finite Difference Time Domain (FDTD) study, and the simulation is performed by the tool RSoft. The spectral variables such as quality factor (QF), sensitivity (Se), transmitted output power and detection limit (DL) are evaluated using the RI value over the spectrum of different toxic gases. The proposed square crystal structure have acquired a QF range of 500.6, high efficiency of 99%, and a better Se of 716.6 nm/RIU at 1502 nm. The designed hexagonal crystal structure have acquired a QF range of 165.8, high efficiency of 99%, and a better Se of 798.24 nm/RIU at 1630 nm respectively. The DL for both the proposed sensors is very low. So, the designed smart sensor helps promptly recognize the contaminated gases in several places. The proposed nanosensor is helpful in industrial safety, health care applications, aerospace, agricultural, transportation, environmental monitoring, thermal plants and mines.

InP CDM and ICR Enabled 128Gbaud/ DP-16QAM-PS and 120Gbaud/DP-QPSK Long-Haul Transmission

We experimentally demonstrated record rOSNR performance for both 400 Gb/s and 800 Gb/s transmissions over EDFA-only 1500 and 1000 km SSMF, respectively, by using ≥64 GHz 3 dB bandwidth InP coherent driver modulator (CDM) and intradyne coherent receiver (ICR). At 400 Gb/s via 120 Gbaud/DP-QPSK, a 16.1 dB back-to-back (BtB) rOSNR at the 15% oFEC BER threshold of 2e-2 and a large 6.9 dB OSNR margin after 1500 km can be achieved. At 800 Gb/s via 120 Gbaud/DP-16QAM, a BtB rOSNR of 25 dB and an rOSNR after 800 km of 25.8 dB can be achieved. We also observed that by employing probabilistic shaping (PS) with 128Gbaud/DP-16QAM-PS, the BtB rOSNR performance can be further improved by 1.6 dB at a cost of a 1.7 dB lower transmitter output power as compared to those of uniformly-distributed 16QAM. As a result, a 24.3 dB rOSNR and a superior OSNR margin of 2.4 dB after 1000 km transmission can be achieved. The demonstrated state-of-art bandwidth <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> distance performance by using practically implementable InP CDM and ICR shows a promising solution for future line-cards and pluggable modules in long-haul transmission systems.

Spectrally pure far-UVC emission from AlGaN-based LEDs with dielectric band pass filters

AlGaN-based far ultraviolet-C (UVC) light emitting diodes (LEDs) with a peak emission wavelength below 240 nm typically show a long-wavelength tail at >240 nm that is detrimental to the use of the devices for skin-friendly antisepsis. We present the development of far-UVC LEDs with reduced long-wavelength emission using a HfO2/SiO2-based distributed Bragg reflector (DBR) filter. When the DBR filter is directly mounted on an LED package, the long-wavelength emission around 250 nm is reduced by two orders of magnitude while the transmitted output power is reduced down to 18%–27% of the initial value for DBR filters with cut-off wavelengths at 237–243 nm. As the transmission through the DBR filter depends strongly on the angle of incidence of the radiation, the transmitted output power of the spectrally pure far-UVC radiation can be doubled when an additional collimating lens is used on top of the LED package before passing through the filter.

Design and Implementation of High Directivity Directional Coupler at VHF Band Using Grounding Composed of Strip Lines Technics

This paper proposes a design of high directivity directional coupler (D.C) based on grounding composed of strip lines for high power Radar transmitter at Very High Frequency (VHF), (150 – 200 MHz). The directional coupler is used to check and verify the transmitter output high power, frequency, and reflected signal from an antenna connected with the Radar transmitter. The performance requirements of directional couplers are a strong coupling to reduce the effect on the transmitted output power and high directivity to suppress the interference of the reflected signal from the antenna. So far, various architectures have been proposed to gain high directivity, and there have been many studies used to obtain a strong coupling and higher directivity. However, the conventional architecture of the directional coupler has a directivity of only about 20 dB, and there have been difficulties to achieve the higher directivity of more than 20 dB. In this paper, the proposed architecture of directional coupler based on grounding composed of strip lines is discussed and compares the test results of the proposed directional coupler with the conventional one. The high directivity directional coupler is designed using a computer-aided design Simulation program; Advance Design System (ADS 2016), using Rogers 4003 substrate. The directional coupler was fabricated on printed circuit board (PCB) technology and measured using a vector network analyzer (VNA). The results show that the proposed directional coupler has directivity between -25 to -24 dB inside the working bandwidth and is adequate for a high-power radar transmitter.

Optical limiting behavior, nonlinear optical studies, geometrical descriptors, chemical properties data, topology analysis on tetraethylammonium L-tartarate dihydrate crystals

The slow cooling technique was utilized to grow organic single crystals of tetraethylammonium L-tartarate dehydrate (EAT) with dimensions 20 × 4 × 4 mm3. The meta stable zone width was obtained via solubility curve. Structural confirmation was achieved using X-ray diffraction. EAT possesses noncentro symmetric P21 space group within the monoclinic crystal structure. Optical transmittance in the visible region reveals a strong transparency with lower cutoff wavelength of 261 nm. EAT crystal’s refractive index is 1.611. The EAT compound's thermal stability was found to be 115 °C, measured by TG-DTA experiments. EAT's specific heat capacity is be 3.670 g −1 K −1. The laser damage threshold of grown EAT crystal surface was measured at 0.3611 GW/cm2. Vicker's microhardness, Kurtz-Perry Powder Method evaluated the mechanical power, particle size based second harmonic generation efficiency (SHG) which identified phase matching in EAT. The SHG maker Fringes technique investigated the SHG of EAT. Optical limiting analysis showed transmitted output power rises linearly till 2.736 mW mm−2 of irradiance.

Semi-Supervised and Supervised Nonlinear Equalizers in Fiber-FSO Converged System

We leverage the supervised and semi-supervised Volterra nonlinear equalizers (VNLE) to mitigate the system nonlinearity. Two methods are employed to estimate the coefficients: ordinary least square (OLS) estimator and the least absolute shrinkage and selection operator (Lasso). Due to the additional coupling loss and higher propagation loss in bad weather conditions, FSO-fiber link requires a more stringent power budget. Higher modulation depth and transmitter output power can improve the link budget but need to make nonlinearity correction. Thus, we comprehensively perform a proof-of-concept demonstration in a fiber-FSO converged link with pulse amplitude modulation (PAM). Compared with conventional supervised VNLE using OLS, the coefficients estimated from Lasso require a smaller training symbol overhead. In both the 50-Gbaud PAM4 (at the 1.22 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−2</sup> threshold) and 35-Gbaud PAM8 (at the 2 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−2</sup> threshold) cases, when the labeled data proportion is 5%, supervised VNLE using Lasso exhibits a received optical power (ROP) improvement up to 3 dB, compared to supervised VNLE using OLS. Moreover, the semi-supervised method can utilize the unlabeled data and further improve the performance without adding signal overhead to the system. In our 50-Gbaud PAM4 experiment, with 60% unlabeled data, the semi-supervised VNLE based on the soft decision (SD) and Lasso demonstrates up to 3-dB sensitivity gain at the BER threshold of 4.5 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup> compared with the supervised VNLE using Lasso. The semi-supervised VNLE using SD and Lasso also demonstrates a line rate improvement >100% at the 4.5 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup> Pre-FEC BER threshold over the conventional supervised VLNE using OLS.

АТТЕНЮАТОР С ЦИФРОВЫМ УПРАВЛЕНИЕМ НА БАЗЕ МОДУЛЯ М44752

Attenuators are often used in radio receivers to expand the dynamic range of input signals,as well as to control the output power of radio transmitters. Recently, attenuators are used intransceiver modules of active antenna arrays. Attenuators differ in operating frequency range,base of elements, control method, operating power. An urgent task is the creation and research ofnew microcircuits of attenuators with digital control of domestic production. The purpose of thiswork is an experimental research of the main parameters and characteristics of a digital attenuatorof the decimeter wave range. The object of the study is an attenuator of the M44752 type installedon the test board. It is manufactured by JSC "SPE "Istok" named after A.I. Shokin". Theresults of the experimental research are given in the operating frequency range from 0.1 to 2 GHz.There are a switching circuit, a photo of a model and six amplitude-frequency characteristics fordifferent control codes. The following electrical parameters have been achieved: – operating frequencyrange is from 0.1 to 2 GHz; – attenuation range is from 1 to 50 dB; – permissible inputpower is not more than 23 dBm; – the number of control bits is 6; – switching time is not morethan 50 ns;– VSWR of input and output is not more than 2. The obtained results of the study of theM44752 module can be used in ultra-wideband transceiver communication equipment for variouspurposes, navigation and radiolocation. The relevance of the research is confirmed by two currenttrends – microminiaturization of electronic equipment and import substitution.

An Ultra-Wideband Compact TR Module Based on 3-D Packaging

This study presents a novel four-channel tile-type T/R module which achieves excellent performances in ultra-wideband (2–12 GHz) and integrates all circuits in a super-light (25 g) and compact (27.8 × 27.8 × 12 mm3) mechanical structure in active phased array systems. The key advancement of this T/R module was to choose a Ball Grid Array (BGA) as the vertical interconnection and bracing between High-Temperature Co-fired Ceramic (HTCC) substrates in order to achieve a high-integration 3-D structure. Exploiting the HTCC multilayer layout, this paper presents the design and development of an ultra-wideband, compact and light, high-output power, four-channel, dual-polarization Transmit/Receive (T/R) Module. In this module, microwave circuits and power control circuits are highly integrated into electrically isolated HTCC layers or substrates, resulting in low coupling and crosstalk between signals. Furthermore, multichip assembly technology, multifunctional MMICs, and other high-integration technologies were adopted for this module. Each channel could provide more than 2 W transmit output power, more than 15 dB receive gain, and less than 5 dB receive noise figure. Every module contains four channels. The power supply and phase/amplitude conditioning of each channel can be controlled individually and showed good consistency of the amplitude and phase of all channels. The connectors of manifold port and polarization ports are all SSMP, which can achieve further integration. This module has also an automatic negative power protection function. The module has stabilized performance and mass production prospects.

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%.

A Digitally Controlled Multichannel Spectrally Efficient Low-Power Transceiver for Ultra-Wideband Cognitive Radio Applications

A multichannel transceiver design with low hardware complexity, flexibility and efficient spectrum use intended for Impulse Radio (IR) Ultra-Wideband (UWB) apertures, is proposed in this paper. The transceiver supports 14 channels and is implemented in TSMC CMOS process. The transmitter adopts a symmetrical triangular narrow pulse generator, a multiband LC-VCO, a mixer and a Variable-Gain Amplifier. A digital control of transmitter output power and carrier frequency is achieved by a current-steering Digital-to-Analog Converter (CS-DAC). The receiver follows the noncoherent Energy Detection (ED) scheme including Low-Noise Amplifier (LNA) which takes the benefits of the body biasing technique to further reduce power consumption, squarer and comparator. The LNA achieves high gain of up to 30[Formula: see text]dB allowing to enhance the receiver sensitivity which is [Formula: see text]83.7[Formula: see text]dBm at 25[Formula: see text]Mbps. The transmitter provides output pulses with a width of 3[Formula: see text]ns, a pulse repetition rate of 20[Formula: see text]ns and a maximum Power Spectral Density (PSD) of [Formula: see text]42[Formula: see text]dBm/MHz. The power consumptions of transmitter and receiver are 35.6[Formula: see text]pJ/bit and 0.207[Formula: see text]nJ/bit at 25[Formula: see text]Mbps, respectively. Maximizing utilization of the scarce wireless spectrum, enhancing spectral flexibility and efficiency and reducing power consumption are the main contributions brought by this work, enabling this transceiver to be able to deal with the current debate on producing single multifunctional Cognitive Radio (CR) UWB systems.

Sub-Terahertz Wireless System Using Dual-Polarized Generalized Spatial Modulation With RF Impairments

In this paper, we address a multiple-input multiple-output (MIMO) communication system based on generalized spatial modulation (GSM) and dual-polarized (DP) antennas in sub-TeraHertz (sub-THz) bands to improve the Spectral Efficiency (SE) while reducing the spatial correlation effect and the space occupancy. Moreover, the joint Maximum Likelihood (ML) detector and a Modified Ordered Block Minimum Mean-Squared Error (MOB-MMSE) detector algorithm are proposed to detect jointly the complex symbols and the virtual bits conveyed by the activated polarization and the transmit antenna combination index. MOB-MMSE can achieve near-ML performance with low complexity. The performance of DP-GSM system over correlated Rayleigh/Rician fading and indoor sub-THz channels is studied. Provided results show that DP-GSM system is robust to the spatial correlation effects under Rician fading channel. In addition, an average bit-error probability (ABEP) upper bounding is derived and analyzed for the DP-GSM system over correlated Rayleigh/Rician fading channels. Since the sub-THz band suffers from many technological limitations and severe RF-impairments such as low transmit output power and important phase noise (PN), the DP-GSM system is studied by considering the sub-THz impairments. Moreover, the Dual Polarized Spatial Multiplexing (DP-SMX) and the Uni-Polarized GSM (UP-GSM) are compared with the DP-GSM system. The results reveal that DP-GSM with low order modulation schemes as QPSK outperforms the UP-GSM. Besides, DP-GSM and DP-SMX provide a good performance up to medium PN, which is interesting for sub-THz bands, but DP-GSM can reduce the transceiver cost by using a lower number of RF chains when the used transmitter architecture is based on RF-switching.