Performance of aluminum nitride-based piezoelectric micromachined ultrasonic transducers under different readout configurations

Author(s):  
Lei Shi ◽  
Licheng Jia ◽  
Chongbin Liu ◽  
Hongbin Yu ◽  
Chengliang Sun ◽  
...  

Abstract In this paper, a low noise amplification circuit is designed for aluminum nitride (AlN)-based piezoelectric micromachined ultrasonic transducers (PMUTs) with three diffenent sensing configurations. The acoustic pressure sensitivity and noise resolution of PMUTs corresponding to different readout configurations are analyzed and characterized. With the differential readout configuration, the acoustic pressure sensitivity of the PMUTs is improved by 5.76 dB (re: 1 V/μPa) on average, and the noise resolution is reduced by about 8 dB at 500 Hz (re: 1 μPa/√Hz). Compared to the conventional readout configuration, both theoretical analysis and measurement results show that the output voltage of PMUTs is doubled with the differential readout configuration and thus the acoustic pressure sensitivity is improved. Moreover, the noise resolution of PMUTs is reduced and thus the signal-to-noise (SNR) is improved. This work offers new insight on improving the receiving performance of PMUTs.

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2590
Author(s):  
Alexandre Robichaud ◽  
Dominic Deslandes ◽  
Paul-Vahé Cicek ◽  
Frederic Nabki

This paper proposes a system in package (SiP) for ultrasonic ranging composed of a 4 × 8 matrix of piezoelectric micromachined ultrasonic transducers (PMUT) and an interface integrated circuit (IC). The PMUT matrix is fabricated using the PiezoMUMPS process and the IC is implemented in the AMS 0.35 µm technology. Simulation results for the PMUT are compared to the measurement results, and an equivalent circuit has been derived to allow a better approximation of the load of the PMUT on the IC. The control circuit is composed of a high-voltage pulser to drive the PMUT for transmission and of a transimpedance amplifier to amplify the received echo. The working frequency of the system is 1.5 MHz.


2019 ◽  
Vol 28 (08) ◽  
pp. 1920005 ◽  
Author(s):  
Tian Qi ◽  
Songbai He

A broadband low-noise amplifier (LNA) using 0.13 [Formula: see text]m GaAs HEMT technology for Ku-band applications is presented in this paper. By introducing an improved self-bias architecture, the LNA is achieved with low noise figure (NF) and high power gain. Compared with traditional LNA, self-bias architecture can reduce DC supplies to single one, and the improved architecture proposed here also takes part in source matching to reduce the complexity matching networks for broadband applications. To verify, an LNA operating over 12–18-GHz bandwidth is fabricated. The measurement results, for all the 72 chips on the wafer, and their average values are in great accordance with the simulation results, with 25.5–27.5-dB power gain, 1.1–1.8-dB NF, 15–17.5-dBm output power at [Formula: see text] and with a chip size of 2 mm [Formula: see text] 1.5 mm.


2012 ◽  
Vol 29 (6) ◽  
pp. 772-795 ◽  
Author(s):  
Lei Lei ◽  
Guifu Zhang ◽  
Richard J. Doviak ◽  
Robert Palmer ◽  
Boon Leng Cheong ◽  
...  

Abstract The quality of polarimetric radar data degrades as the signal-to-noise ratio (SNR) decreases. This substantially limits the usage of collected polarimetric radar data to high SNR regions. To improve data quality at low SNRs, multilag correlation estimators are introduced. The performance of the multilag estimators for spectral moments and polarimetric parameters is examined through a theoretical analysis and by the use of simulated data. The biases and standard deviations of the estimates are calculated and compared with those estimates obtained using the conventional method.


2005 ◽  
Vol 892 ◽  
Author(s):  
Qianghua Wang ◽  
Jianzeng Xu ◽  
Changhe Huang ◽  
Gregory W Auner

AbstractThis paper reports the fabrication and characterization of micromachined ultrasonic transducers (MUT) based on piezoelectric aluminum nitride (AlN) thin films. The MUT device is composed of an Al/AlN/Al sandwiched structure overlaid on top of a silicon (Si) diaphragm. X-ray diffraction (XRD) scan shows that highly c-axis oriented AlN (002) thin films have been grown on Al/Si(100) substrates. Electrical impedance of the MUT devices is analyzed as a function of frequency. The fundamental resonant frequencies of the devices are found in the range of 65-70 kHz, which are in approximation to the theoretical calculation. The effective coupling factors of the devices are also derived as 0.18.


Author(s):  
Christian Werner ◽  
Carsten Buschmann ◽  
Tobias Jäcker ◽  
Stefan Fischer

Although Web service technology is being used in more and more distributed systems, its areas of application are inherently limited by high latencies and high amounts of protocol overhead. For messaging in environments with user interaction, like Web platforms for business or multimedia applications, the response time of the whole system needs to be kept in tight boundaries. In other scenarios comprising mobile communication and battery-powered devices, bandwidth-efficient communication is imperative. In this chapter we address both of these issues. First we conduct a detailed latency analysis of different transport mechanisms for SOAP and then we thoroughly investigate their protocol overhead. For both aspects we present a theoretical analysis as well as experimental measurement results. We then will introduce a new transport binding called PURE that significantly reduces the protocol overhead while featuring low latency. Furthermore it enables interesting additional features such as point-to-multipoint communication via IP multicast and broadcast.


Electronics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 786 ◽  
Author(s):  
Massimiliano Rossi ◽  
Riccardo Liberati ◽  
Marco Frasca ◽  
John Richardson

It is quite common for transceivers to operate with the RF receiver and transmitter working on different time slots. Typical applications are radars and transceivers in the field of communications. Generally, the receiver is turned off when the transmitter broadcasts and vice versa. This is done in order to prevent the transmitter from blinding the receiver or causing the RF low noise amplification (LNA) stage to saturate. When keeping a receiver active, some leakage of RF energy is inevitable, and therefore shielding is applied to mitigate spurious signals. However, there are many applications wherein the receiver cannot be turned off. To address these applications, we investigate the design and performance of a fully-analog self-jamming canceller able to operate in UHF (Ultra High Frequency) RFID devices. While the traditional cost to design and build this type of topology can be quite high, our proposal is based on a low-cost physical approach. In addition to using common SMT (Surface Mount Technology) devices, we leveraged a new piece of modular technology offered by X-Microwave which allows designers to easily produce RF solutions with a broad portfolio of modular system drop-in blocks. A prototype was realized and the measured results are in close agreement with theoretical simulations. Significant damping of the leaked signal in the receiving channel was realized.


1999 ◽  
Vol 11 (6) ◽  
pp. 650-652 ◽  
Author(s):  
M. Hofer ◽  
M.E. Fermann ◽  
A. Galvanauskas ◽  
D. Harter ◽  
R.S. Windeler

2014 ◽  
Vol 1025-1026 ◽  
pp. 987-990
Author(s):  
Jun Oh Yeon ◽  
Kyoung Woo Kim ◽  
Kwan Seop Yang ◽  
Byung Kwon Lee

We have developed a low-noise drainage system, which was installed in bathrooms of apartment building units as well as in a mock-up test building, to evaluate the noise level in order to reduce the noise produced in the bathrooms of multiunit dwellings. The drainage system installed in the mock-up building consists of six types of detachable drains, and the level of noise produced during toilet use in the upper unit was measured in the lower unit. The measurement results showed that low-noise drainage 4 exhibited the Leq(equivalent continuous sound level) at 34.7 dB(A). The noise measurement results of various types of low-noise drains installed in an apartment building showed that the Leqduring toilet use was 46.7 dB(A) on average, and the Leqduring sink use was 40.5 dB(A) on average.


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