scholarly journals Self-Calibrated Measurement of Frequency Response for Broadband Photodetectors Based on Two-Tone Photonic Sampling

2021 ◽  
Vol 9 ◽  
Author(s):  
Mengke Wang ◽  
Ying Xu ◽  
Yutong He ◽  
Zhao Liu ◽  
Yali Zhang ◽  
...  
Keyword(s):  
Frequency Response ◽  
Wide Frequency Range ◽  
Repetition Frequency ◽  
Difference Frequency ◽  
Ultra Wideband ◽  
Center Frequency ◽  
Frequency Range ◽  
Frequency Responses ◽  
Tone Signal ◽  
Photonic Sampling

A self-calibrated method to measuring the frequency responses of broadband photodetectors (PDs) is proposed based on photonic pulse sampling of two-tone microwave signal, with the help of a mode-locked laser diode (MLLD) and a Mach-Zehnder modulator (MZM). Firstly, the repetition frequency of the optical comb from the MLLD divides the whole measuring frequency range into several segments. Then, a close-spaced two-tone signal modulates every comb tooth through the MZM and generates the sum- and difference-frequency products, working as the probing signal to extract the frequency response of the PD in every segment. Hyper-fine frequency response of the PD at any frequency point can be obtained in every segment by subtly varying the center frequency of the two-tone signal while keeping the difference frequency fixed. Finally, the whole frequency response of the PD in ultra-wide frequency range is obtained by seamlessly stitching the segmental frequency responses. In our experiment, measurement of a commercial PD is demonstrated up to 49.765 GHz with an optical comb at the repetition frequency of 9.953 GHz and a two-tone modulation up to 4.9765 GHz. The measured results are compared with those by using the traditional methods to check accuracy. Moreover, the uneven responses of the MLLD and the MZM are fully subtracted, verifying the ultra-wideband, hyperfine and self-calibrated measurement of PDs based on the two-tone photonic sampling.

Design of multi-layered bandpass filter with independently controllable triple-passband response

2014 ◽  
Vol 6 (6) ◽  
pp. 611-618 ◽  
Author(s):  
Yung-Wei Chen ◽  
Hung-Wei Wu ◽  
Yan-Kuin Su
Keyword(s):  
Frequency Response ◽  
Bandpass Filter ◽  
Bottom Layer ◽  
Wide Frequency Range ◽  
Electromagnetic Simulation ◽  
Frequency Range ◽  
High Isolation ◽  
Full Wave ◽  
Simulation Results ◽  
Good Agreement

In this paper, a new multi-layered triple-passband bandpass filter using embedded and stub-loaded stepped impedance resonators (SIRs) is proposed. The filter is designed to have triple-passband at 1.8, 2.4, and 3.5 GHz. The 1st and 2nd passbands (1.8/2.4 GHz) are simultaneously generated by controlling the impedance and length ratios of the embedded SIRs (on top layer). The 3rd passband (3.5 GHz) is generated by using the stub-loaded SIR (on bottom layer). Using the embedded SIR, the even modes can be tuned within very wide frequency range and without affecting the odd modes. Therefore, the design of multi-band filters with very close passbands can be easily achieved and having a high isolation between the passbands. The filter can provide the multi-path propagation to enhance the frequency response and achieving the compact circuit size. The measured results are in good agreement with the full-wave electromagnetic simulation results.

Dynamic Bridge Piezoelectric Amplifiers with Signal Generator

2012 ◽  
Vol 182-183 ◽  
pp. 374-377
Author(s):  
Hai Tao Xin
Keyword(s):  
Frequency Response ◽  
Piezoelectric Actuator ◽  
Power Supply ◽  
Dynamic Performance ◽  
Wide Frequency Range ◽  
Slew Rate ◽  
Frequency Range ◽  
High Demand ◽  
Positioning Accuracy ◽  
New Type

Piezoelectric amplifier is a very important part of the piezoelectric actuator. Not only positioning accuracy, but also dynamic performance and power are demanded more and more highly. At present piezoelectric amplifier are mainly used in static applications, power and frequency response are usually incompatible. This paper developed a new type of piezoelectric amplifier to meet high demand for dynamic, which takes dual-power supply, bridge-output to achieved slew rate, power were doubled, and maintain a wide frequency range at the same time. Controller implements DDS unit through FPGA, which could achieve sine, triangle, square and sawtooth.

The Matched Acoustic Generator

1972 ◽  
Vol 94 (1) ◽  
pp. 11-14
Author(s):  
K. Toda ◽  
G. Roffman ◽  
A. I. Talkin
Keyword(s):  
Measurement Error ◽  
Frequency Response ◽  
Transmission Lines ◽  
Acoustic Signal ◽  
Maximum Error ◽  
Power Gain ◽  
Frequency Range ◽  
Input Line ◽  
Pressure Signal ◽  
Frequency Responses

The design of a swept-frequency, acoustic generator for quickly measuring the insertion power gain and bandwidth of flueric components is described and illustrated. The generator is used to produce and measure the signal incident on flueric components without being affected by reflections from them. The components are connected to the generator by transmission lines. The output of the flueric component is measured in a line of the same diameter as the input line and long enough to attenuate reflections from the far end of the line to negligible levels. The generator produces a 17.7 × 10−3 kilopascal (2.6 × 10−3 psi) acoustic signal in a 1/8 in. (0.32 cm) line over the frequency range of 200 to 5000 Hz. The maximum error in the measurement of the incident pressure signal is approximately 5 percent. More precise construction of the generator could reduce the measurement error, but the accuracy is sufficient for many engineering purposes. The swept-frequency responses and carrier-pulse responses of several flueric amplifiers are illustrated and in particular the frequency response of certain proportional amplifiers has been shown to extend to 4000 Hz.

Mechanical, Acoustic and Electromagnetic Evaluation of the Semi-Implantable Middle Ear Hearing Device (SIMEHD)

1997 ◽  
Vol 76 (5) ◽  
pp. 321-327 ◽  
Author(s):  
Hassan A. Abbass ◽  
Michael Kane ◽  
Steven Garverick ◽  
Wen H. Ko ◽  
Anthony J. Maniglia ◽  
...  
Keyword(s):  
Frequency Response ◽  
Middle Ear ◽  
Electromagnetic Interference ◽  
High Frequency ◽  
Ossicular Chain ◽  
Wide Frequency Range ◽  
Frequency Range ◽  
Force Output ◽  
Margin Of Safety ◽  
Hearing Device

The properties of the partially implantable middle ear hearing device (SIMEHD) were extensively studied. The internal unit was subjected to 5,000 cycles of bending at a force of 75 g (gravity) without failure. An accurate measurement of the force output of the SIMEHD was obtained (14 - 25 dynes/mA). This force is too small to cause any damage to the ossicular chain. The force resulting from electromagnetic interference over a wide frequency range (500 Khz - 1 Giga (109) Hz) was measured and noted to be within the margin of safety. The frequency response plots (500 - 8,000 Hz) were also obtained and revealed an excellent ability to amplify middle and high-frequency sounds.

Designing an ultra-wideband electromagnetic waves receiver with new architecture for RF and wireless applications

2015 ◽  
Vol 8 (8) ◽  
Author(s):  
Mohammad Alibakhshi-Kenari ◽  
Mohammad Naser-Moghadasi ◽  
Ramazan Ali Sadeghzadeh ◽  
Aurora Andújar ◽  
Jaume Anguera
Keyword(s):  
Electromagnetic Waves ◽  
Supply Voltage ◽  
Cmos Technology ◽  
Wide Frequency Range ◽  
Ultra Wideband ◽  
Pulse Position Modulation ◽  
Frequency Range ◽  
Wireless Receiver ◽  
Wireless Applications ◽  
Output Amplitude

This paper demonstrates an electromagnetic waves receiver (EMWR) with new architecture for finding the good performances at the very wide frequency range of 2.8 to 10.8 GHz. The proposed device applies conventional pulse position modulation (PPM) scheme for modulation. The combination of 8th–8th-order derivative of Gaussian pulse is used as impulse received signal. The EMW receiver circuit with core chip dimension of 32 × 10−3 mm2 was modeled in a 90 nm CMOS technology. The output amplitude pulse yielded 200 mV peak-to-peak under a supply voltage of 2.2 V. This circuit consumes 12 pJ/pulse at 0.5 GHz pulse-repeating frequency. The designed device can be employed in the transceiver systems in presence the multipath channel for 2.8 GHz to 10.8 GHz. Results express that the proposed system not only decrease the interference with narrowband (NB) systems, but is also robust against NB interference at the operating frequency of 7 GHz. Regarding to results, the EMWR can be used in radio frequency (RF) and wireless receiver applications.

A miniaturized CPW-fed on-chip UWB monopole antenna with band-notch characteristics

2019 ◽  
Vol 12 (1) ◽  
pp. 95-102
Author(s):  
S. Mandal ◽  
A. Karmakar ◽  
H. Singh ◽  
S. K. Mandal ◽  
R. Mahapatra ◽  
...  
Keyword(s):  
Satellite Communication ◽  
Coplanar Waveguide ◽  
Measured Data ◽  
Ultra Wideband ◽  
Center Frequency ◽  
Frequency Range ◽  
Antenna Structure ◽  
On Chip Antenna ◽  
Layout Area ◽  
On Chip

AbstractThis paper presents the design and analysis of a miniaturized, coplanar waveguide-fed ultra-wideband monopole on-chip antenna with band-notch characteristics. By incorporating a “U”-shaped slot in the feedline, a band-notch is realized in the frequency range of 7.9–8.4 GHz to avoid interference from the X-band uplink satellite communication system. The proposed antenna achieved good voltage standing wave ratio (VSWR) characteristics with VSWR value <2 for the frequency range of 2.5–20.1 GHz excluding the band-notched frequencies. The fractional bandwidth and bandwidth ratio are obtained as 156% and 8.04:1, respectively. Dominant factors that affect the center frequency and bandwidth of the notched band are thoroughly investigated. This paper addresses both frequency as well as time domain behavior of the proposed structure. Standard 675 µm thick, high resistive silicon substrate (ρ≥8 kΩ-cm, εr = 11.8, and tan δ = 0.01) is used to design the proposed compact antenna structure with a layout area of 8.5 × 11.5 mm2. Fabrication process steps along with simulated and measured data are presented here. A close analogy between simulated and measured data is observed.

scholarly journals Multiband linear and circular polarization rotating metasurface based on multiple plasmonic resonances for C, X and K band applications

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
M. Ismail Khan ◽  
Yixiao Chen ◽  
Bin Hu ◽  
Naeem Ullah ◽  
Syed Hashim Raza Bukhari ◽  
...  
Keyword(s):  
Circular Polarization ◽  
Transverse Magnetic ◽  
Wide Frequency Range ◽  
Ultra Wideband ◽  
Ring Resonators ◽  
Frequency Range ◽  
Split Ring ◽  
Compact Structure ◽  
Frequency Bands ◽  
Satellite Radar

Abstract In this work, a multiband polarization converting metasurface is presented which achieves cross-polarization conversion in five frequency bands while linear-to-circular and circular-to-linear polarization transformation in eight frequency bands. The polarization transforming functionality of the structure is spread over an ultra-wide frequency range (5–37 GHz) covering most of X, C, Ku, K and Ka bands. Such an extraordinary ultra-wideband operation originates from multiple plasmonic resonances occurring in the structure based on two coupled rectangular split-ring resonators. Moreover, the polarization transforming capability is stable within the frequency range 5–19 GHz for wide oblique incidence angles, which is up to 60°, both for transverse-electric and transverse-magnetic polarizations. Furthermore, the proposed structure acts as a meta-mirror which preserves handedness of the circular polarization upon reflection. Measurements performed on the fabricated metasurface are found to be consistent with numerical simulation results. The ability to perform three functionalities through a single compact structure with extraordinary wideband, qualifies the proposed design to be a promising candidate for integration with important microwave applications such as satellite, radar, and 5G communication.

scholarly journals Detection and localization of multiple small damages in beam

2021 ◽  
Vol 13 (1) ◽  
pp. 168781402098732
Author(s):  
Ayisha Nayyar ◽  
Ummul Baneen ◽  
Syed Abbas Zilqurnain Naqvi ◽  
Muhammad Ahsan
Keyword(s):  
Frequency Response ◽  
Natural Frequencies ◽  
Signal To Noise Ratio ◽  
Moving Average ◽  
A Priori ◽  
Damage Index ◽  
High Signal ◽  
Frequency Range ◽  
Spatial Locality ◽  
System Frequency

Localizing small damages often requires sensors be mounted in the proximity of damage to obtain high Signal-to-Noise Ratio in system frequency response to input excitation. The proximity requirement limits the applicability of existing schemes for low-severity damage detection as an estimate of damage location may not be known  a priori. In this work it is shown that spatial locality is not a fundamental impediment; multiple small damages can still be detected with high accuracy provided that the frequency range beyond the first five natural frequencies is utilized in the Frequency response functions (FRF) curvature method. The proposed method presented in this paper applies sensitivity analysis to systematically unearth frequency ranges capable of elevating damage index peak at correct damage locations. It is a baseline-free method that employs a smoothing polynomial to emulate reference curvatures for the undamaged structure. Numerical simulation of steel-beam shows that small multiple damages of severity as low as 5% can be reliably detected by including frequency range covering 5–10th natural frequencies. The efficacy of the scheme is also experimentally validated for the same beam. It is also found that a simple noise filtration scheme such as a Gaussian moving average filter can adequately remove false peaks from the damage index profile.

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