An L-band SiGe HBT differential amplifier with frequency and rejection-level tunable, multiple stopband

2009 ◽  
Vol 1 (4) ◽  
pp. 285-292 ◽  
Author(s):  
Masaki Shirata ◽  
Toshio Shinohara ◽  
Minoru Sato ◽  
Yasushi Itoh
Keyword(s):  
Bias Voltage ◽  
Frequency Tuning ◽  
Differential Amplifier ◽  
Tank Circuit ◽  
Band Frequency ◽  
Varactor Diode ◽  
Sige Hbt ◽  
Active Load ◽  
Rejection Level ◽  
L Band

An L-band frequency and rejection-level tunable SiGe HBT differential amplifier with dual stopband is presented. To achieve frequency and rejection-level tunable performance, dual LCR-tank circuit with an active load is incorporated into the design of the series feedback loops of the differential amplifier. The active load consists of a varactor diode represented as a variable C and a common-emitter transistor represented as a variable R. The frequency and rejection level can be tuned independently by controlling a cathode bias voltage of the varactor diode or a base bias voltage of the transistor. The implemented 0.35 μm SiGe HBT amplifier with dual stopband demonstrates a frequency tuning of 0.53–1.16 GHz and a rejection-level variation up to 9.5 dB. The input and output return losses are better than 17.5 and 11 dB over 0.2–1.5 GHz, respectively. The measured P1dB is+3 dBm and IIP3 is 0 dBm with Vcc = 6 V and Ic = 8 mA.

scholarly journals A Dual-Band SiGe HBT Frequency-Tunable and Phase-Shifting Differential Amplifier Employing Varactor-Loaded, Stacked LC Resonators

2012 ◽  
Vol 2012 ◽  
pp. 1-7
Author(s):  
Kazuyoshi Sakamoto ◽  
Yasushi Itoh
Keyword(s):  
Tuning Range ◽  
Frequency Tuning ◽  
Phase Variation ◽  
Phase Shifting ◽  
Differential Amplifier ◽  
Dual Band ◽  
Sige Hbt ◽  
Frequency Tunable ◽  
Lc Resonators ◽  
Frequency Phase

A dual-band SiGe HBT frequency-tunable and phase-shifting differential amplifier has been developed for the future active phased array antennas with a multiband, multibeam, and multitarget tracking operation. The amplifier uses varactor-loaded, stacked LC resonators in the design of the output circuit in order to provide frequency-tunable and phase-shifting capabilities for dual frequencies. By utilizing the varactor-loaded LC resonator, which has a variable resonant frequency and a large insertion phase variation, frequency-tunable and phase-shifting performances become available. Moreover, by using the stacked configuration, the frequency and insertion phase can be varied independently for dual frequencies. A dual-band SiGe HBT differential amplifier has achieved a lower-frequency tuning range of 0.56 to 0.7 GHz for a higher fixed frequency of 0.97 GHz as well as a higher-frequency tuning range of 0.92 to 1.01 GHz for a lower fixed frequency of 0.63 GHz. A lower-frequency phase variation of 99° and a higher-frequency phase variation of 90.3° have been accomplished at 0.63 and 0.97 GHz, respectively. This is the first report on the dual-band differential amplifier with frequency-tunable and phase-shifting capabilities.

Breath air measurement using wide-band frequency tuning IR laser photo-acoustic spectroscopy

2016 ◽  
Author(s):  
Yury V. Kistenev ◽  
Alexey V. Borisov ◽  
Dmitry A. Kuzmin ◽  
Anna A. Bulanova ◽  
Andrey A. Boyko ◽  
...  
Keyword(s):  
Frequency Tuning ◽  
Wide Band ◽  
Band Frequency ◽  
Ir Laser ◽  
Acoustic Spectroscopy ◽  
Photo Acoustic Spectroscopy

Surface-based and Fully Polarimetric L-band Frequency Scatterometer System for Field Measurements of Sea Ice

2021 ◽  
Author(s):  
Randall Kenneth Scharien ◽  
Torsten Geldsetzer ◽  
Jim Mead ◽  
Vishnu Nandan ◽  
Mallik Mahmud ◽  
...  
Keyword(s):  
Sea Ice ◽  
Field Measurements ◽  
Band Frequency ◽  
L Band

scholarly journals DESIGN OF CARTESIAN FEEDBACK RF POWER AMPLIFIER FOR L-BAND FREQUENCY RANGE

2008 ◽  
Vol 2 ◽  
pp. 207-222 ◽  
Author(s):  
Jit Singh Mandeep ◽  
Anand Lokesh ◽  
Syed Idris Syed Hassan ◽  
mohd nazri Mahmud ◽  
Mohd Fadzil Ain
Keyword(s):  
Power Amplifier ◽  
Rf Power ◽  
Frequency Range ◽  
Band Frequency ◽  
Rf Power Amplifier ◽  
L Band

A Frequency-Tunable Comb Resonator Using Spring Tension and Compression Effects

2004 ◽  
Author(s):  
Ki Bang Lee ◽  
Albert P. Pisano ◽  
Liwei Lin
Keyword(s):  
Resonant Frequency ◽  
Bias Voltage ◽  
Frequency Tuning ◽  
Electrostatic Force ◽  
Voltage Change ◽  
Tension And Compression ◽  
Frequency Tunable ◽  
Frequency Changes ◽  
Compression Effects ◽  
First Time

A 2μm-thick frequency-tunable microresoantor capable of either increasing or decreasing its resonant frequency by a combination of Joule heating and electrostatic force has been successfully demonstrated for the first time. For the heating voltage increase from 0 to 2V under fixed bias voltage of 40V, the resonant frequency changes from 22.2kHz to 16.2kHz, resulting in the 27% reduction in the resonant frequency. For the bias voltage change from 20V to 40V under the heating voltage of 0V, the resonant frequency increase from 19.0kHz to 23.6kHz, resulting in the 24.2% increase in the resonant frequency. As such, this surface-micromachined microactuator could assist complicated frequency tuning for applications of microsensors and microactuators.

scholarly journals Study of spatial and temporal characteristics of L-band scintillations over the Indian low-latitude region and their possible effects on GPS navigation

2006 ◽  
Vol 24 (6) ◽  
pp. 1567-1580 ◽  
Author(s):  
P. V. S. Rama Rao ◽  
S. Gopi Krishna ◽  
K. Niranjan ◽  
D. S. V. V. D. Prasad
Keyword(s):  
Indian Region ◽  
Sunspot Activity ◽  
Navigation Systems ◽  
Positional Accuracy ◽  
Band Frequency ◽  
Latitude Range ◽  
Ionospheric Scintillations ◽  
Simultaneous Study ◽  
L Band ◽  
Spatio Temporal

Abstract. The scintillation data (S4-index) at the L-band frequency of 1.575GHz, recorded from a total of 18 GPS receivers installed at different locations in India under the GAGAN project, have provided us with a unique opportunity, for the first time in the Indian region, to make a simultaneous study of spatio-temporal and intensity characteristics of the trans-ionospheric scintillations during the 18-month, low sunspot activity (LSSA) period from January 2004 to July 2005. During this period, the occurrence of scintillations is found to be maximum around the pre-midnight hours of equinox months, with very little activity during the post-midnight hours. No significant scintillation activity is observed during the summer and winter months of the period of observation. The intensity (S4 index) of the scintillation activity is stronger around the equatorial ionization anomaly (EIA) region in the geographic latitude range of 15° to 25° N in the Indian region. These scintillations are often accompanied by the TEC depletions with durations ranging from 5 to 25 min and magnitudes from 5 to 15 TEC units which affect the positional accuracy of the GPS by 1 to 3 m. Further, during the intense scintillation events (S4>0.45≈10 dB), the GPS receiver is found to lose its lock for a short duration of 1 to 4 min, increasing the error bounds effecting the integrity of the SBAS operation. During the present period of study, a total of 395 loss of lock events are observed in the Indian EIA region; this number is likely to increase during the high sunspot activity (HSSA) period, creating more adverse conditions for the trans-ionospheric communications and the GPS-based navigation systems.

Resonant Frequency Tuning of Piezoelectric Ultrasonic Microsensors by Bias Voltage Application to Extra Top-Electrodes on PZT Diaphragms

2010 ◽  
Vol 408 (1) ◽  
pp. 48-54 ◽  
Author(s):  
Kaoru Yamashita ◽  
Kenji Tomiyama ◽  
Keita Yoshikawa ◽  
Minoru Noda ◽  
Masanori Okuyama
Keyword(s):  
Resonant Frequency ◽  
Bias Voltage ◽  
Frequency Tuning ◽  
Voltage Application
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