scholarly journals 245 GHz SiGe sensor system for gas spectroscopy

2015 ◽  
Vol 7 (3-4) ◽  
pp. 271-278 ◽  
Author(s):  
Klaus Schmalz ◽  
Ruoyu Wang ◽  
Wojciech Debski ◽  
Heiko Gulan ◽  
Johannes Borngräber ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Second Harmonic ◽  
Local Oscillator ◽  
Low Noise ◽  
Gas Absorption ◽  
Sensor System ◽  
Phase Locked Loops ◽  
Reference Frequency ◽  
Constant Frequency ◽  
Noise Amplifier

A 245 GHz sensor system for gas spectroscopy is presented, which includes a SiGe receiver (RX), a SiGe transmitter (TX), and a 0.6 m long gas absorption cell between the TX and RX. The integrated local oscillators of the RX and the TX are controlled by two external phase locked loops (PLLs), whose reference frequencies are swept with constant frequency offset for a low IF of the RX. The RX consists of a differential low noise amplifier (LNA), an integrated 122 GHz local oscillator (LO) with 1/64 divider, a 90° differential hybrid, and active subharmonic mixer. The TX consists of an integrated 122 GHz LO with 1/64 divider, and a frequency doubler. The RX and TX are fabricated in 0.13 µm SiGe BiCMOS with ft/fmax of 300/500 GHz. Using external dielectric lenses for the TX and RX, the absorption spectrum of gaseous methanol has been measured. The reference frequency of the TX-PLL is modulated for frequency-modulation spectroscopy. The performance of the sensor system is demonstrated by measuring the 2f absorption spectrum (second harmonic detection) of gaseous methanol.

Research and Design of a Large Bandwidth Receiver RF Front-End

2014 ◽  
Vol 926-930 ◽  
pp. 2503-2507
Author(s):  
Wen Kai Liu ◽  
Peng Wang ◽  
Jian Cui
Keyword(s):  
Communication System ◽  
Local Oscillator ◽  
Low Noise ◽  
Center Frequency ◽  
Large Bandwidth ◽  
Front End ◽  
Rf Front End ◽  
Noise Amplifier ◽  
The Stability ◽  
Rf Signal

RF front-end is an important part of the communication system. It realizes the functions such as low noise amplifier application, filtering and mixing, completes the conversion between the IF signal and the RF signal, and ensures effective communication system flexibility and versatility. In the paper, according to the superheterodyne structure, a receiver RF front-end has been designed. The total gain of the link circuit is more than 100 dB, with 50 dB AGC range, the center frequency is 750 MHz with 100MHz bandwidth, local oscillator (LO) signal with frequency 935MHz is generated by PLL and the stability is-82dBc/Hz@1KHz.

scholarly journals Analysis and Detection of a Target Gas System Based on TDLAS & LabVIEW

2019 ◽  
Vol 9 (3) ◽  
pp. 4196-4199 ◽  
Author(s):  
F. Alorifi ◽  
S. M. A. Ghaly ◽  
M. Y. Shalaby ◽  
M. A. Ali ◽  
M. O. Khan
Keyword(s):  
Absorption Spectrum ◽  
Second Harmonic ◽  
Detection System ◽  
Infrared Absorption Spectrum ◽  
Gas Absorption ◽  
Tunable Diode Laser ◽  
Gas Detection ◽  
Measured Signal ◽  
Gas Concentration ◽  
Detection Techniques

This paper introduces detection techniques of target gas concentration based on infrared absorption spectrum method and the simulation of the gas detection system using LabVIEW. In this work, the harmonic detection is performed by wavelength modulation technique with a related frequency signal to cover the measured signal and get the gas absorption coefficient that can be analysed to give a gas concentration. A series of simulations are carried out to scan weak absorption lines and extract the second harmonic curve of the absorption spectrum of the target gas. The absorption and second harmonic curves are acquired by changing the parameters of the target gas concentration and line width. This work claims to be a contribution to the study and the comprehension of gas detection system based on tunable diode laser absorption spectroscopy and can serve as a basis for practical data acquisition.

scholarly journals The resting frequency of echolocation signals changes with body temperature in the hipposiderid bat, Hipposideros armiger

2022 ◽  
Author(s):  
Diana Schoeppler ◽  
Annette Denzinger ◽  
Hans-Ulrich Schnitzler
Keyword(s):  
Body Temperature ◽  
Second Harmonic ◽  
Circadian Variation ◽  
Frequency Component ◽  
Reference Frequency ◽  
Constant Frequency ◽  
Emission Frequency ◽  
Warm Up ◽  
Vocal Control ◽  
And Function

Doppler shift (DS) compensating bats adjust in flight the second harmonic of the constant-frequency component (CF2) of their echolocation signals so that the frequency of the Doppler shifted echoes returning from ahead is kept constant with high precision (0.1-0.2%) at the so-called reference frequency (fref). This feedback adjustment is mediated by an audio-vocal control system which correlates with a maximal activation of the foveal resonance area in the cochlea. Stationary bats adjust the average CF2 with similar precision at the resting frequency (frest), which is slightly below the fref. Over a variety of time periods (from minutes up to years) variations of the coupled fref and frest have been observed, and were attributed to age, social influences and behavioural situations in rhinolophids and hipposiderids, and to body temperature effects and flight activity in Pteronotus parnellii. We assume that, for all DS compensating bats, a change in body temperature has a strong effect on the activation state of the foveal resonance area in the cochlea which leads to a concomitant change in emission frequency. We tested our hypothesis in a hipposiderid bat, Hipposideros armiger, and measured how the circadian variation of body temperature at activation phases affected frest. With a miniature temperature logger, we recorded the skin temperature on the back of the bats simultaneously with echolocation signals produced. During warm-up from torpor strong temperature increases were accompanied by an increase in frest, of up to 1.44 kHz. We discuss the implications of our results for the organization and function of the audio-vocal control systems of all DS compensating bats.

Doppler-shift compensation by the mustached bat: quantitative data.

1994 ◽  
Vol 188 (1) ◽  
pp. 115-129 ◽  
Author(s):  
A W Keating ◽  
O W Henson ◽  
M M Henson ◽  
W C Lancaster ◽  
D H Xie
Keyword(s):  
Doppler Shift ◽  
Quantitative Data ◽  
Second Harmonic ◽  
Frequency Component ◽  
Reference Frequency ◽  
Constant Frequency ◽  
Doppler Shifts ◽  
Mustached Bat ◽  
Pteronotus Parnellii ◽  
Significant Difference

Quantitative data for Doppler-shift compensation by Pteronotus parnellii parnellii were obtained with a device which propelled the bats at constant velocities over a distance of 12 m. The bats compensated for Doppler shifts at all velocities tested (0.1-5.0 ms-1). The main findings were (1) that compensation was usually accomplished by a progressive lowering of the approximately 61 kHz second harmonic constant-frequency component of emitted sounds in small frequency steps (93 +/- 72 Hz); (2) that the time needed to reach a steady compensation level averaged 514 +/- 230 ms and the number of pulses required to reach full compensation averaged 10.78 +/- 5.16; (3) that the animals compensated to hold the echo (reference) frequency at a value that was slightly higher than the resting frequency and slightly lower than the cochlear resonance frequency; (4) that reference frequency varied as a function of velocity, the higher the velocity of the animal, the higher was the reference frequency (slope 55 Hz m-1s-2); and (5) that the mean reference frequency was always an undercompensation. The average amount of undercompensation was 15.8%. There was a significant difference (P < or = 0.005) in Doppler-shift compensation data collected at velocities that differed by 0.1 ms-1. A velocity difference of 0.1 ms-1 corresponds to a Doppler-shift difference of about 35 Hz in the approximately 61 kHz signals reaching the ear.

scholarly journals Research, Design and Fabrication Microwave Modules of Receiver for NanoDragon satellite at S band

2019 ◽  
Vol 35 (2) ◽  
Author(s):  
Bui Thi Ha ◽  
Bach Gia Duong
Keyword(s):  
Research Design ◽  
Transmission Rate ◽  
Local Oscillator ◽  
High Gain ◽  
Low Noise ◽  
Low Noise Amplifier ◽  
Two Stage ◽  
Ground Station ◽  
Noise Amplifier

Abstract: In the paper, the new microwave modules of NanoDragon satellite’s receiver were designed and fabricated. Purpose of this design is not only reduce budget but also respond to frequency requirement, bandwidth and transmission rate. The microwave modules consist of low noise amplifier (LNA), mixer and local oscillator (LO). These modules operate at S band according to requirement of satellite. Firstly, each module was designed, simulated, fabricated and measured. Then they were integrated together. Output of integrated microwave modules is IF signal with bandwidth is suitable for demodulation PCM – PM (BPSK). And have high gain value conform to receiver’s requirement. Simulation result of low noise amplifier is 19.108 dB at 2.9 GHZ. Simulation result of integrating two stage LNA become 2-stage LNA have gain value over 38 dB. Gain value obtained is 11.5 dB when measurement. Integrating microwave modules result is 10.5 dB with gain value. That mean this microwave modules of receiver operated very well. LNA was very good. This subsystem can apply for NanoDragon satellite’s receiver and receiver of ground station. Keywords: Receiver, Microwave Modules of Receiver, Satellite, NanoDragon satellite, LNA, Mixer, LO, IF.

Features of the development of broadband frequency mixers with suppression of the mirror channel in the range frequencies 9–27 GHz

2020 ◽  
Vol 23 (3) ◽  
pp. 68-73
Author(s):  
Grigoriy A. Uglov ◽  
Yulia V. Belova
Keyword(s):  
Field Effect Transistors ◽  
Local Oscillator ◽  
Low Noise ◽  
Package Design ◽  
Foreign Products ◽  
Image Channel ◽  
Functional Units ◽  
Noise Amplifier ◽  
Frequency Mixer ◽  
Broadband Frequency

The article is devoted to features of the development two types of broadband frequency mixers with image channel suppression in the frequency range 927 GHz. The purpose of the study is to determine the optimal ways to solve the problem of modeling complex multifunctional microwave units. The article discusses the development process of such functional units as the local oscillator amplifier, low-noise amplifier and frequency mixer. Comparisons of the calculated characteristics with the results of measurements of the manufactured models of the samples are given. Attention is also paid to the technology of manufacturing field-effect transistors, resistors and capacitors that are part of the functional units of the frequency mixer. The scientific novelty lies in the uniqueness of the product development, which includes several functional units on one crystal. As a result, two types of frequency mixers with suppression of the mirror channel in a package design have been created, which, in terms of their characteristics, can replace similar foreign products from Analog Devices.

A subharmonic front-end in SiGe:C technology for 94-GHz imaging arrays

2009 ◽  
Vol 1 (4) ◽  
pp. 361-368
Author(s):  
Erik Öjefors ◽  
Johannes Borngräber ◽  
Falk Korndörfer ◽  
Ullrich Pfeiffer
Keyword(s):  
Supply Voltage ◽  
Local Oscillator ◽  
Low Noise ◽  
Conversion Gain ◽  
Imaging Arrays ◽  
Matching Networks ◽  
Front End ◽  
Current Consumption ◽  
Noise Amplifier ◽  
A Current

The design of a subharmonic downconverter for 94-GHz imaging arrays in SiGe:C technology is presented. A three-stage differential low-noise amplifier (LNA) with lumped matching networks is used together with a subharmonic mixer driven by a single-pole local-oscillator poly-phase network to form the front-end. The LNA yields 15 dB gain at 94 GHz, while the mixer provides 5 dB conversion gain over a 10 GHz IF bandwidth. The integrated downconverter provides 20 dB conversion gain at 94 GHz with an input 1-dB compression point of −31 dBm and has a current consumption of 45 mA at a 3.3 V supply voltage. The total required die area of the complete downconverter (excluding pad frame) is 0.1 mm, thus making it particularly suitable as a front-end in multi-channel receiver systems.

The personalized auditory cortex of the mustached bat: adaptation for echolocation

1987 ◽  
Vol 58 (4) ◽  
pp. 643-654 ◽  
Author(s):  
N. Suga ◽  
H. Niwa ◽  
I. Taniguchi ◽  
D. Margoliash
Keyword(s):  
Auditory Cortex ◽  
Second Harmonic ◽  
Frequency Component ◽  
Masking Effect ◽  
Reference Frequency ◽  
Sexually Dimorphic ◽  
Constant Frequency ◽  
Mustached Bat ◽  
Pteronotus Parnellii ◽  
Almost All

1. In the mustached bat, Pteronotus parnellii, the "resting" frequency of the constant-frequency component of the second harmonic (CF2) of the orientation sound (biosonar signal) is different among individuals within a range from 59.69 to 63.33 kHz. The standard deviation of CF2 resting frequency is 0.091 kHz on the average for individual bats. The male's CF2 resting frequency (61.250 +/- 0.534 kHz, n = 58) is 1.040 kHz lower than the female's (62.290 +/- 0.539 kHz, n = 58) on the average. Females' resting frequencies measured in December are not different from those measured in April when almost all of them are pregnant. Therefore, the orientation sound is sexually dimorphic. 2. In the DSCF (Doppler-shifted CF processing) area of the auditory cortex, tonotopic representation differs among individual bats. The higher the CF2 resting frequency of the bat's own sound, the higher the frequencies represented in the DSCF area of that bat. There is a unique match between the tonotopic representation and the CF2 resting frequency. This match indicates that the auditory cortex is "personalized" for echolocation and that the CF2 resting frequency is like a signature of the orientation sound. 3. If a bat's resting frequency is normalized to 61.00 kHz, the DSCF area overrepresents 60.6-62.3 kHz. The central region of this overrepresented band is 61.1-61.2 kHz. This focal band matches the "reference" frequency to which the CF2 frequency of a Doppler-shifted echo is stabilized by Doppler-shift compensation. 4. Since DSCF neurons are extraordinarily sharply tuned in frequency, the personalization of the auditory cortex or system is not only suited for the detection of wing beats of insects, but also for the reduction of the masking effect on echolocation of consepecific's biosonar signals. 5. Because the orientation sound is sexually dimorphic and the auditory cortex is personalized, the tonotopic representation of the auditory cortex is also sexually dimorphic.

A new method of fluxgate signal extraction

2017 ◽  
Vol 2017 (45) ◽  
pp. 83-89
Author(s):  
A.A. Marusenkov ◽  
Keyword(s):  
High Frequency ◽  
Second Harmonic ◽  
Excitation Frequency ◽  
Low Noise ◽  
Measuring System ◽  
Signal Extraction ◽  
Fluxgate Magnetometer ◽  
New Approach ◽  
Average Value ◽  
The Time Domain

Using dedicated high-frequency measuring system the distribution of the Barkhausen jumps intensity along a reversal magnetization cycle was investigated for low noise fluxgate sensors of various core shapes. It is shown that Barkhausen (reversal magnetization) noise intensity is strongly inhomogeneous during an excitation cycle. In the traditional second harmonic fluxgate magnetometers the signals are extracted in the frequency domain, as a result, some average value of reversal magnetization noises is contributed to the output signals. In order to fit better the noise shape and minimize its transfer to the magnetometer output the new approach for demodulating signals of these sensors is proposed. The new demodulating method is based on information extraction in the time domain taking into account the statistical properties of cyclic reversal magnetization noises. This approach yields considerable reduction of the fluxgate magnetometer noise in comparison with demodulation of the signal filtered at the second harmonic of the excitation frequency.

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