Injected Signal Power Research Articles

Experimental Study of High Power Microwave Injection in Radar Receiving Front-end

In order to study the tolerance threshold and damage process of radar receiving front end against high power microwave pulse attack, the relationship between the damage of receiving front end and injected signal power, pulse width, and duration was obtained by injection test. The experimental results show that the damage of PIN limiter by high power microwave is a slow worsening process near the damage threshold. Based on the test results, the radar withstanding range of high-power microwave weapon attack is calculated theoretically, which can provide theoretical support for the radar receiving front-end design.

Over 250 W low noise core-pumped single-frequency all-fiber amplifier.

A high-power linearly-polarized all-fiber single-frequency amplifier at 1 µm based on tandem core-pumping is demonstrated by using a large-mode-area Ytterbium-doped fiber with a core diameter of 20 µm, which nicely balances the stimulated Brillouin scattering effect, thermal load, and output beam quality. A maximum output power of more than 250 W with a corresponding slope efficiency of >85% is achieved at the operating wavelength of 1064 nm without being constrained by the saturation and nonlinear effects. Meanwhile, a comparable amplification performance is realized with a lower injection signal power of the wavelength near the peak gain of the Yb-doped fiber. The polarization extinction ratio and the M2 factor of the amplifier are respectively measured to be >17 dB and 1.15 under the maximal output power. In addition, by virtue of the single-mode 1018 nm pump laser, the intensity noise of the amplifier under maximal output power is measured to be comparable to that of the single-frequency seed laser at frequencies higher than 2 kHz, except for the emergence of parasitic peaks that can be eliminated by optimizing the driving electronics of the pump lasers, while the deterioration of the amplification process to the frequency noise and linewidth of the laser is negligible. To the best of our knowledge, this is the highest output power of a single-frequency all-fiber amplifier based on the core-pumping scheme.

Analysis and Design of Power-Efficient H-Band CMOS Frequency Doubler Employing Gain Boosting and Harmonic Enhancing Techniques

This article presents a power-efficient frequency doubler employing gain boosting and harmonic-enhancing techniques. With a single transistor only, the gain boosting technique can reach the maximum achievable gain ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> ) by adding embedded passive components, thereby obtaining high voltage swings. Then, the transistor’s nonlinearity is essential, which is maximized by the harmonic transition scheme of the transistor operation along with high voltage swings. In addition, a harmonic reflector and a harmonic leakage canceller are employed for the second harmonic enhancement. The harmonic reflector prevents unwanted harmonic mixing by minimizing the incoming second harmonic current fed back to the input. The harmonic leakage canceller suppresses the leakage loss of the second harmonic current present at the output. Furthermore, thanks to a proposed dual-band output matching network, the output impedance is conjugately matched to achieve the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> at the fundamental frequency while it is matched to extract the second harmonic output power simultaneously. To verify the proposed techniques, the prototype was designed as a single-stage circuit that does not require additional amplifying stages, which led to higher power efficiency and lower chip area. Implemented in a 65-nm CMOS process, the measurement results show a saturated output power of 0.9 dBm and 3-dB bandwidth of 26 GHz (237-263 GHz), respectively, while requiring a chip area of 0.071 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Total power efficiency, including the effect of injected signal power, is 2.87 % while consuming only 37 mW dc power.

Monolithic all-fiberized nanosecond laser with kilowatt average power and megawatt peak power

We demonstrate an all-fiberized less than 10 ns master oscillator power amplifier (MOPA) with an average power of more than 1 kW, pulse energy of ∼ 10 mJ, and peak power of ∼ 0.78 MW using pulse distortion and narrowing of 30 ns laser pulses as the seed beam. The effects of the pulse width of the seed laser and injected signal power on the pulse narrowing were investigated theoretically and experimentally. By simulations, we proved that a longer signal pulse width could be compressed more effectively than a pulse with a shorter width. Moreover, the increase of the injected power could promote the narrowing of the amplified pulse. Experimentally, the distortion and narrowing of 30 ns laser pulse can effectively improve the maximum output power free of nonlinear optical effects such as stimulated Raman scattering (SRS) of all-fiberized less than 10 ns amplifiers. We also found an optimal combination of the pumping and injected power to achieve a trade-off between the SRS and amplified spontaneous emission (ASE) to obtain the highest SRS-free output power and narrowest pulse width.

Total gain of InTlAsSb quantum dot structures

Abstract This work studies the total gain of the InTlAsSb quantum dot structure, which is not studied earlier. Adding thallium to structures makes it emit at larger wavelengths. The nonlinear effect of the injected signal power is examined for three quaternary thallium structures: In0.85Tl0.15AsSb, In0.93Tl0.07AsSb and In0.97Tl0.03AsSb. The gain peak was increased by four times and the wavelength was shifted to longer one for the In0.97Tl0.03AsSb quantum dot (QD) structure. This quaternary QD structure extends the emission wavelength to more than 12 μm which is important in long-wavelength infrared applications. The nonlinear behavior of these QD structures is also addressed. It is shown that the structure In0.97Tl0.03AsSb has a deeper spectral hole burning which is adequate for nonlinear signal processing applications.

Injection Locking and Parametric Locking in a Superconducting Circuit

When a signal is injected in a parametric oscillator close enough to its resonance, the oscillator frequency and phase get locked to those of the injected signal. Here, we demonstrate two frequency locking schemes using a Josephson mixer in the parametric down-conversion regime, pumped beyond the parametric oscillation threshold. The circuit then emits radiation out of two spectraly and spatially separated resonators at frequencies determined by the locking schemes that we choose. When we inject the signal close to a resonance, it locks the oscillator emission to the signal frequency by injection locking. When we inject the signal close to the difference of resonances, it locks the oscillator emission by parametric locking. We compare both schemes and investigate the dependence of the parametric locking range on the pump and the injection signal power. Our results can be interpreted using Adler's theory for lasers, which makes a new link between laser physics and superconducting circuits that could enable better understanding of pumped circuits for quantum information applications such as error correction, circulators and photon number detectors.

Experimental Study on the Phase Deviation of 20-kW &lt;inline-formula&gt; &lt;tex-math notation="LaTeX"&gt;$S$ &lt;/tex-math&gt; &lt;/inline-formula&gt;-Band CW Phase-Locked Magnetrons

Phase-control precision is important for applications of magnetrons in the microwave source array. Here, experimental results use a 20-kW $S$ -band continuous-wave magnetron to investigate the phase deviation of large-power phase-locked magnetrons. For the first time, the phase deviation of a 20-kW magnetron controlled through an externally injected signal was studied. The phase deviation of the injection-locked magnetron output worsened gradually, the greater the difference in frequency of the injected signal (with the same injection ratio) from the center of magnetron injection-locked bandwidth was. When the injected power was maintained at 150 W and the magnetron output was at 19 kW, the maximum phase deviation was varied from approximately 1° to 6° with frequency tuning. In addition, the phase deviation of the phase-locked magnetron decreased as the injected signal power increased at a given frequency.

Experimental investigation of transmission characteristics of continuous variable entangled state over optical fibers

Continuous variable (CV) quantum entanglement is an essential resource for quantum computation and communication protocols. The use of CV quantum entanglement at a telecommunication wavelength of 1.5m in combination with existing fiber telecommunication networks offers the possibility to implement long-distance quantum communication protocols like quantum key distribution (QKD) and applications such as quantum repeaters, quantum teleportation in the future. In spite of the fact that the optical power attenuation of light in a standard telecommunication fiber is lowest at a wavelength of 1.5m, the entangled states will interact with fiber channels and the disentanglement will occur. It is one of the important factors restricting the development of long distance quantum information. In this paper, CV entangled state at 1.5m telecommunication band is obtained by using a type-II periodically poled KTP (PPKTP) crystal inside a nondegenerate optical parametric amplifier (NOPA). A wedged PPKTP is used for implementing frequency-down-conversion of the pump field to generate the optically entangled state and achieving the dispersion compensation between the pump and the subharmonic waves. By controlling the temperature and the length of the PPKTP crystal, a triply resonant optical parametric oscillator with a threshold of 80 mW is realized. Einstein-PodolskyRosen (EPR)-entangled beams with quantum correlation of 8.3 dB for both the amplitude and phase quadratures are experimentally generated by using a single NOPA at a pump power of 40 mW and an injected signal power of 10 mW when the relative phase between the pump and injected signal is locked to . The generated entangled state is coupled into a single-mode optical fiber, and the transmission characteristics of the generated EPR entangled beams through standard single-mode fibers are investigated experimentally and theoretically. A fiber polarization controller is used to compensate for the polarization state variation induced by random fluctuations of birefringence of the single mode fiber when the light propagates along the fiber, and to keep the polarization of light linear at the fiber output. A 0.21 dB quantum entanglement could still be observed for the EPR-entangled beams transmitted through a 50-km-long single-mode fiber. The theoretical prediction considering the excess noise in fiber channel is in good agreement with the experimental result. The generated CV quantum entanglement is highly suitable for the required experiments, such as CV measurement-device-independence QKD based on standard fibers, owing to the fact that the tolerance of the excess noise in the quantum channel can be enhanced significantly with respect to a coherent state if EPR-entangled beams are used.

Wide‐locking range single‐injection divide‐by‐3 injection‐locked frequency divider

ABSTRACTThis letter presents a wide‐locking range CMOS divide‐by‐3 injection‐locked frequency dividers (ILFD) using single‐ended injection signal. The fabricated 0.18 μm CMOS ÷3 ILFD uses cross‐coupled switching transistors, single‐injection MOSFET, and a dual‐resonance RLC resonator. The consumed power of the ÷3 ILFD core is 7.97 mW at the DC drain‐source voltage 0.76 V. At an external injected signal power Pinj = 0 dBm, the measured locking range is 2.97 GHz (25.25%) from 10.28 to 13.25 GHz and the operation range is 5.17 GHz (48.5%) from 8.08 to 13.25 GHz. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2720–2723, 2015

A V‐band frequency quadrupler using subharmonic injection‐locked oscillator with push–push technique

ABSTRACTA V‐band frequency quadrupler with high output power characteristic has been implemented and fabricated using 0.15 µm GaAs pHEMT technology. This quadrupler circuit is achieved by a second‐order subharmonic injection‐locked oscillator and a push–push frequency doubler as the output buffer. The free‐running oscillation frequency of the core oscillator is around 35 GHz with a tuning range of 3.25 GHz covering from 33.25 to 36.5 GHz. Using push–push circuit to be a frequency doubler under a proper bias condition, an optimized second harmonic signal can be accomplished with high harmonic suppression. The frequency of output signal in the quadrupler can present a wide tuning range from 66.5 to 73 GHz, and the maximum output power is −1.25 dBm with total dc consumption of 56 mW. With injecting a second‐order subharmonic signal into the core oscillator, the circuit exhibits an injection locking with an output locking range of about 1.6 GHz from 69.2 to 70.8 GHz. The output phase noise for 70‐GHz signal can be improved better than −105 dBc/Hz at 1 MHz frequency offset when the injected signal power is higher than 0 dBm. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2473–2480, 2014

A 10.5‐GHz divide‐by‐3 injection‐locked frequency divider with enhanced locking range by even‐harmonic phase tuning in 0.18 μm BiCMOS

ABSTRACTA fully integrated 10.5‐GHz divide‐by‐3 (1/3) injection‐locked frequency divider (ILFD) that can provide extra locking range is presented. The ILFD consists of a previously measured on‐chip 10.5‐GHz voltage controlled oscillator (VCO) functioning as an injection source, a 1/3 ILFD core, and an output inverter buffer. A phase tuner implemented using an asymmetric inductor is proposed to increase the locking range through even‐harmonic phase tuning. With a fixed internal injection signal power of only −18 dBm, a 25% enhancement in the locking range from 12 to 15 MHz is achieved with the proposed phase tuning. The proposed even‐harmonic phase tuning can be used to provide extra locking range to those achieved by other techniques. The proposed integrated 1/3 ILFD has a frequency tuning range of 3.3–4.2 GHz. It is realized using a 0.18‐μm BiCMOS process, occupies 0.6 mm × 0.7 mm, and consumes 10.6 mA while the ILFD core alone only consumes 6.15 mA from 1.8‐V supply voltage. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2249–2252, 2014

Systematic Analysis of Crosstalk Noise in Folded-Torus-Based Optical Networks-on-Chip

Photonic devices are widely used in optical networks-on-chip (ONoCs) and suffer from crosstalk noise. The accumulative crosstalk noise in large scale ONoCs diminishes the signal-to-noise ratio (SNR), causes severe performance degradation, and constrains the network scalability. For the first time, this paper systematically analyzes and models the worst-case crosstalk noise and SNR in folded-torus-based ONoCs. Formal analytical models for the worst-case crosstalk noise and SNR are presented. The crosstalk noise analysis is hierarchically performed at the basic photonic device level, then at the optical router level, and finally at the network level. We consider a general 5 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\,\times\,$</tex></formula> 5 optical router model to enable crosstalk noise and SNR analyses in folded-torus-based ONoCs using an arbitrary 5 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\,\times\,$</tex> </formula> 5 optical router. Using the general optical router model, the worst-case SNR link candidates, which restrict the network scalability, are found. Also, we present a novel crosstalk noise and loss analysis platform, called CLAP, which can analyze the crosstalk noise and SNR of arbitrary ONoCs. Case studies of optimized crossbar and Crux optical routers using recent photonic device parameters are presented. Moreover, we compare the worst-case crosstalk noise and SNR in folded-torus-based and mesh-based ONoCs using optimized crossbar and Crux optical routers. The quantitative simulation results show the critical behavior of crosstalk noise in large scale ONoCs. For example, in folded-torus-based ONoCs using the Crux optical router, the noise power exceeds the signal power for network sizes larger than 12 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\,\times\,$</tex></formula> 12; when the network size is 20 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\,\times\,$</tex></formula> 20 and the injection signal power equals 0 dBm, the signal power and noise power are <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${-}{\rm 9.4}~{\rm dBm}$</tex></formula> and <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${-}{\rm 6.1}~{\rm dBm}$</tex></formula> , respectively.

Study of Link Gain and Locking Range in Hybrid Mode‐Locked Laser‐Based MillimeteR‐Wave Radio‐Over‐Fiber System

ABSTRACTAn investigation of hybrid mode‐locked lasers is performed to better understand their link gain and locking range behavior under external RF injection for their use in millimeter wave radio‐over‐fiber systems. The dependence of 40‐GHz link gain on different parameters is initially identified and then the three main parameters of gain and saturable absorber section biases and external RF injection signal power are studied in detail. It is found that higher injection power leads to lower link gain ranging from −19dB to −22dB, whereas lower injection power gives higher link gain ranging from −10dB to −19.9dB. This article also reports a hybrid mode‐locking range of 90.97 MHz which is the widest reported so far for the technique used here. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2450–2454, 2013

Wide‐Locking Range Dual‐Band Injection‐Locked Frequency Divider

ABSTRACTA wide locking range divide‐by‐2 CMOS LC‐tank injection locked frequency divider is proposed and is realized with two mixers in series and a cross‐coupled oscillator with dual‐resonance LC resonator to provide large output voltage swings at high‐ and low‐frequency bands. The dual‐band function can be obtained without switching. Measurement results show that at the supply voltage of 0.8 V, the free‐running frequency is from 3.571 to 3.974 GHz for the high‐frequency band and from 2.278 to 2.349 GHz for the low‐frequency band. At Vtune = 1.2 V, an external injected signal power of 0 dBm provides a low‐band divide‐by‐2 locking range (57.7%) from 2.87 to 5.2 GHz and a high‐band locking range (25.7%) from 7.1 to 9.2 GHz. At Vtune = 0 V an external injected signal power of 0 dBm provides a high‐band locking range (46.5%) from 5.6 to 9 GHz and a low‐band locking range (25.0%) from 2.8 to 3.6 GHz. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2333–2337, 2013

Low power dual transformer injection locked frequency divider using 0.5 μm GaAs E/D-mode PHEMTs process

This letter proposes a new divide-by-2 injection locked frequency divider (ILFD) fabricated by 0.5 μm GaAs ED-Mode PHEMTs process and describes the operation principle of the dual-transformer ILFD. The first transformer is applied to replace two inductors of the cross-couple LC-tank oscillator circuit. The injection signal of the ILFD transmits into a transistor through a second transformer, which consisted of a bandpass filter achieving a high injection signal power and wide locking range. The measurement results show that the divider's free-running frequency were from 6.47 to 9.54 GHz (32.2%) with 3 V supply voltage. With an incident power of 0 dBm, the locking range is 3.07 GHz from the incident frequency 16.41 to 19.45 GHz (15.6%). The measured phase noise of free running VCO is −92.2 dBc/Hz at 1 MHz offset frequency at 9.45 GHz and this value of the locked ILFD is −128.4 dBc/Hz, which is 36.2 dB lower than the free running VCO. The core power consumption was 42 mW. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2302–2306, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25442

All‐optical clock division with simultaneous wavelength conversion using an optically injected Fabry‐Perot laser diode

AbstractThe authors propose and experimentally demonstrate a novel technique that uses a single Fabry‐Perot laser diode (FP‐LD) to perform simultaneous all‐optical clock division and wavelength conversion. By utilizing the nonlinear dynamical period‐one oscillation and the cross‐gain modulation effect of the light injection semiconductor laser, we achieve the all optical clock frequency division of 12.36 GHz to 6.18 GHz with simultaneous wavelength conversion from 1550.24 nm to 1545.91 nm. The phase noise of the extracted optical clock is less than −105 dBc/Hz. It was empirically found that the best clock division and wavelength conversion occurred when the injected signal power was approximately 2–2.5 times as the injected probe light power, and the range of optimum wavelength detuning was about from −0.01 nm to 0.06 nm. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2428–2431, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24626

Quadrature Hartley VCO and Injection-Locked Frequency Divider

Novel low phase noise quadrature voltage-controlled oscillator (QVCO) and quadrature injection locked frequency divider (QILFD) with two coupled Hartley VCOs are proposed and implemented using the standard TSMC 0.18μm CMOS 1P6M process. The QVCO employs pMOS as the core to reduce the up-conversion of low-frequency device noise to RF phase noise. It uses super-harmonic coupling technique to couple two differential Hartley VCOs and four small-size coupling transistors to set the directivity of quadrature output phases. At the 1.7V supply voltage, the output phase noise of the QVCO is -124dBc/Hz at 1MHz offset frequency from the carrier frequency of 4.12GHz, and the figure of merit is -185dBc/Hz. At the supply voltage of 1.7V, the total power consumption is 13.1mW. At the supply voltage of 1.5V, the tuning range of the free-running QILFD is from 2.05GHz to 2.36GHz, about 310MHz, and the locking range of the ILFD is from 3.99 to 5.19GHz, about 1.20GHz, at the injection signal power of 0dBm.

A transformer‐coupled LC‐tank injection locked frequency divider

AbstractThis article designs an injection locked frequency divider (ILFD) based on the direct injection technique and transformer‐coupled VCO topology. At the supply voltage of 3.3 V, the tuning range of the free‐running ILFD is from 2.47 to 2.32 GHz, about 150 MHz, and the locking range of the ILFD is from 4.58 to 5.09 GHz, about 510 MHz at the injection signal power of 0 dBm. The ILFD dissipates 188 mW at 3.3 V supply voltage and was fabricated in the TSMC 0.35 μm CMOS 2P4M CMOS technology. At the tuning voltage of 2.5 V, the measured phase noise of free‐running ILFD is about −116.7 dBc/Hz at 1 MHz offset frequency from 2.4 GHz, and the phase noise of the locked ILFD is about −128.6 dBc/Hz, while the input signal is with a power of −4 dBm. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 592–595, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23150

All-optical NOR gate based on injection-locking effect in a semiconductor laser

A scheme for all-optical NOR logic gate is proposed based on injection-locking effect in a semiconductor laser. In this scheme, signal light injection into the laser will cause frequency shift of laser modes, as a result, the probe light into the laser can be switched between injection-locked and unlocked status, and its output power will be modulated. Theoretical analysis for this scheme is carried out by using a model to describe the dynamics of the injection-locked laser. By numerical simulation, the influence of laser bias current, laser length, injected signal power and signal frequency on the output performance of NOR logic gate is quantitatively analyzed.

Injection Locked Coupled Oscillator Arrays

The dynamics of injection locked coupled oscillator arrays operating as phase-shifters is studied. In these systems the choice of the injection signal power is of great importance as it directly affects the maximum achievable phase shift range. Its influence over the system performance is studied by means of harmonic balance simulations. These arrays present several coexisting solutions for fixed values of the system parameters. The stability of the various solutions is studied through envelope transients simulations. The different analyses proposed allow a complete evaluation of the system performance, enabling an optimum choice of the injection-locking power.