Control Architecture for 30MHz Linear Imaging Array

2003 ◽  
Author(s):  
R. L. Tutwiler ◽  
J. P. Stitt ◽  
K. K. Shung ◽  
Q. Wu ◽  
T. A. Ritter ◽  
...  
Keyword(s):  
High Frequency ◽  
High Speed ◽  
Very High Frequency ◽  
Front End ◽  
High Speed Data Acquisition ◽  
Under Construction ◽  
The Individual ◽  
Test Phantom ◽  
Signal Interface ◽  
Very High

The purpose of this system is to have the capability to characterize the performance of very high frequency transducers and arrays. The analog front end is computer controlled by a set of de-multiplexers and multiplexers. The output of the multiplexer network is connected to a TGC array, which is interfaced to a high-speed data acquisition system. A software GUI (Graphical User Interface) has been designed to accomplish this task [1]. A programmable digital I/O interface allows collection of RF channel data and has the capability to be interfaced to a very high frequency analog beam-former under construction. The system front-end electronics (pulsers, receivers, T/R switches, multiplexers, and demultiplexers) have been characterized [2, 3]. The digital I/O signal interface has been integrated and tested. The hardware front end has been integrated to the array interface distribution panel. The individual transducer elements impulse responses have been evaluated and the performance of the array has been tested with a wire test phantom to characterize lateral and axial resolution.

Structural, Optical and Electrical Properties of μc-SiC:H Thin Films Deposited by the VHF-GD

1994 ◽  
Vol 358 ◽  
Author(s):  
Roger Fluckiger ◽  
J. Meier ◽  
A. Shah ◽  
J. Pohl ◽  
M. Tzolov ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Gas Phase ◽  
High Frequency ◽  
Input Power ◽  
Optical And Electrical Properties ◽  
Very High Frequency ◽  
Deposition Parameters ◽  
Temperature And Pressure ◽  
The Individual ◽  
Very High

ABSTRACTIn the present paper the authors present new results on thin (μc-SiC:H films deposited at low temperatures by the Very High Frequency - Glow Discharge technique (VHF-GD) at 70 MHz. The individual effects of each of the deposition parameters (methane and diborane gas phase ratios, input power, deposition temperature and pressure) are investigated with respect to the structural, optical and electrical properties of the films; the goal being the growth of optimised, thin μc-SiC:H layers for use as highly conductive and high gap window layers in solar cells.

INTEGRATED SiGe AND Si DEVICE CAPABILITIES AND TRENDS FOR MULTI-GIGAHERTZ APPLICATIONS

2003 ◽  
Vol 13 (01) ◽  
pp. 175-219 ◽  
Author(s):  
G. G. FREEMAN ◽  
B. JAGANNATHAN ◽  
N. ZAMDMER ◽  
R. GROVES ◽  
R. SINGH ◽  
...  
Keyword(s):  
Silicon Substrate ◽  
High Frequency ◽  
High Speed ◽  
Very High Frequency ◽  
Silicon Photodiode ◽  
Sige Hbt ◽  
Wide Range ◽  
On Chip ◽  
Silicon Based ◽  
Very High

Silicon-based devices, including the increasingly available SiGe-based devices, are now demonstrating fT and fMAX values over 200 GHz. These recent advances open the door to a wide range of silicon-based very high frequency, low power and highly integrated solutions. Trends in silicon MOS, SiGe HBT, SiGe MODFET and SiGe strained silicon FETs are reported. Silicon inroads to device functions viewed as the sole realm of III-V technologies are also being demonstrated. Capability and trends of the integrated silicon photodiode are reported here as an example. Integration of these high-speed devices into a complex circuit requires on-chip passive device functionality at such high frequency. Key devices to enable integration are the inductor, varactor, and transmission line, and operation of these devices at high frequency is reported. Further, we discuss noise isolation issues and techniques, which may be used when minimizing cross-talk within a conductive silicon substrate.

scholarly journals Impact of High-Speed Lines in Relation to Very High Frequency Air Services

2005 ◽  
Vol 8 (2) ◽  
pp. 17-35 ◽  
Author(s):  
Andrés López-Pita ◽  
Francesc Robusté
Keyword(s):  
High Frequency ◽  
High Speed ◽  
Very High Frequency ◽  
Very High

High‐Speed Organic Single‐Crystal Transistor Responding to Very High Frequency Band

2020 ◽  
Vol 30 (11) ◽  
pp. 1909501 ◽  
Author(s):  
Akifumi Yamamura ◽  
Takaaki Sakon ◽  
Kayo Takahira ◽  
Takahiro Wakimoto ◽  
Mari Sasaki ◽  
...  
Keyword(s):  
Single Crystal ◽  
Frequency Band ◽  
High Frequency ◽  
High Speed ◽  
High Frequency Band ◽  
Very High Frequency ◽  
Organic Single Crystal ◽  
Very High

ANALOGUE SIGNAL PREDICTOR: FREQUENCY-DOMAIN ANALYSIS

2007 ◽  
Vol 17 (10) ◽  
pp. 3715-3719 ◽  
Author(s):  
MANTAS MEŠKAUSKAS ◽  
ARŪNAS TAMAŠEVIČIUS ◽  
KȨSTUTIS PYRAGAS
Keyword(s):  
Frequency Domain ◽  
High Frequency ◽  
High Speed ◽  
Domain Analysis ◽  
Frequency Domain Analysis ◽  
Operational Amplifiers ◽  
Very High Frequency ◽  
Analogue Signal ◽  
Very High

Frequency-domain analysis of the recently suggested analogue signal predictor is performed. In addition, the operation of the circuit is demonstrated in the high frequency and very high frequency ranges by means of PSPICE simulator employing high-speed operational amplifiers.

Experimental Investigation of very High Frequency Slot Antenna on M-60A-1 Tank

1977 ◽  
Author(s):  
D. V. Campbell ◽  
William Kennebeck ◽  
A. Zanella ◽  
Paul Sexton
Keyword(s):  
Experimental Investigation ◽  
High Frequency ◽  
Slot Antenna ◽  
Very High Frequency ◽  
Very High

A collision feedback based multiple access control protocol for very high frequency data exchange system in E-navigation

2021 ◽  
pp. 1-16
Author(s):  
Xu Hu ◽  
Bin Lin ◽  
Ping Wang ◽  
Hongguang Lyu ◽  
Tie-Shan Li
Keyword(s):  
Access Control ◽  
High Frequency ◽  
Multiple Access ◽  
Data Exchange ◽  
High Frequency Data ◽  
Frequency Data ◽  
Exchange System ◽  
Very High Frequency ◽  
Time Division ◽  
Very High

Abstract The very high frequency data exchange system (VDES) is promising in promoting electronic navigation (E-navigation) and improving navigation safety. The multiple access control (MAC) protocol is crucial to the transmission performance of VDES. The self-organising time division multiple access (SOTDMA) protocol, as the only access mode given by current recommendations, leads to a high rate of transmission collisions in the traditional automatic identification system (AIS), especially with heavy traffic loads. This paper proposes a novel feedback based time division multiple access (FBTDMA) protocol to address the problems caused by SOTDMA, such that collision of transmissions can be avoided in information transmission among vessels. Simulation results demonstrate that the proposed FBTDMA outperforms the traditional SOTDMA in terms of channel utilisation and throughput, and significantly reduces the transmission collision rate. The study is expected to provide insights into VDES standardisation and E-navigation modernisation.

scholarly journals Measurement of Electrical Properties of Superconducting YBCO Thin Films in the VHF Range

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3360
Author(s):  
Yakir Dahan ◽  
Eldad Holdengreber ◽  
Elichai Glassner ◽  
Oz Sorkin ◽  
Shmuel E. Schacham ◽  
...  
Keyword(s):  
Thin Films ◽  
Theoretical Model ◽  
Quality Factor ◽  
High Frequency ◽  
Unit Length ◽  
Superconducting Thin Films ◽  
Electrical Parameters ◽  
Very High Frequency ◽  
Production Constraints ◽  
Very High

A new measurement technique of electrical parameters of superconducting thin films at the Very High Frequency (VHF) range is described, based on resonators with microstrip (MS) structures. The design of an optimal resonator was achieved, based on a thorough theoretical analysis, which is required for derivation of the exact configuration of the MS. A theoretical model is presented, from which an expression for the attenuation of a MS line can be derived. Accordingly, simulations were performed, and an optimal resonator for the VHF range was designed and implemented. Production constraints of YBa2Cu3O7 (YBCO) limited the diameter of the sapphire substrate to 3″. Therefore, a meander configuration was formed to fit the long λ/4 MS line on the wafer. By measuring the complex input reflection coefficients of a λ/4 resonator, we extracted the quality factor, which is mainly affected by the dielectric and conductor attenuations. The experimental results are well fitted by the theoretical model. The dielectric attenuation was calculated using the quasi-static analysis of the MS line. An identical copper resonator was produced and measured to compare the properties of the YBCO resonator in reference to the copper one. A quality factor of ~6·105 was calculated for the YBCO resonator, three orders of magnitude larger than that of the copper resonator. The attenuation per unit length of the YBCO layer was smaller by more than five orders of magnitude than that of the copper.

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