Navigation Links
How to make microwaves on a chip to replace X-rays for medical imaging and security
Date:5/29/2008

Is microwave radiation the nondestructive imaging technology of the future? Microwaves with frequencies from a few hundred gigahertz (GHz) up to slightly over 1 terahertz (THz), penetrate just a short distance into surfaces without the ionizing damage caused by X-rays. The technology could be used to detect skin cancer or image dental flaws beneath the enamel. It could also be a valuable tool for airport security, to detect objects hidden under clothing.

Most of these applications require inexpensive portable hardware that can generate signals in the GHz to THz range with more than 1 watt of power. However, transistors on a standard silicon chip have been limited to a few milliwatts at up to about 100 GHz.

Now a method of generating high-power signals at frequencies of 200 GHz and higher on an ordinary silicon chip has been proposed by Ehsan Afshari, Cornell assistant professor of electrical and computer engineering, and Harish Bhat, assistant professor of mathematics at the University of California-Merced. The researchers present a mathematical analysis of the new method in the May issue of the journal Physical Review E.

Afshari and Bhat propose to use a phenomenon known as nonlinear constructive interference. Linear constructive interference occurs when two signals that are in phase that is, with their peaks and valleys matched produce a new signal as large as both added together. But if the signals are traveling through an uneven medium, the waves can become distorted, some delayed, some moving ahead to produce a "nonlinear" result that combines many small waves into fewer large peaks. Afshari likens the effect to the breaking of waves on the seashore. In the open ocean, waves travel as smooth undulations. But near shore the waves encounter an uneven surface at varying depths and become distorted into breakers.

To create this effect on a chip, the researchers propose a lattice of squares made up of inductors the equivalent of tiny coils of wire with each intersection grounded through a capacitor. An electrical wave moves across the lattice by alternately filling each inductor then discharging the current into the adjacent capacitor. A capacitor temporarily stores and releases electrons, and these capacitors, made of layers of silicon and silicon dioxide, are designed to vary their storage capacity as the voltage of the signal changes, creating the equivalent of the varying depths of an ocean beach and distorting the timing of the electrical signals that pass by.

When low-frequency, low-power signals are applied simultaneously to both the vertical and horizontal wires of the lattice, the waves they produce interfere as they meet across the lattice, combining many small waves into one large peak. The process produces harmonic signals at multiples of the original frequency, and a high-power, high-frequency signal can be read out somewhere in the middle of the lattice.

According to computer simulations by Afshari and Bhat, the process can be implemented on a common complimentary metal-oxide silicon (CMOS) chip to generate signals at frequencies well above the ordinary cutoff frequencies of such chips, with at least 10 times the input power. Frequencies up to around 1.16 THz are possible, the researchers predict.


'/>"/>

Contact: Blaine Friedlander
bpf2@cornell.edu
607-254-8093
Cornell University Communications
Source:Eurekalert

Related biology news :

1. Research examines factors in delaying or declining total knee replacement surgery
2. Testosterone replacement theraphy beneficial in men 60 and older
3. MU researcher links hormone replacement therapy to breast cancer
4. Listen-up ladies: Dont postpone knee-replacement surgery
5. Single-largest biodiversity survey says primary rainforest is irreplaceable
6. Lensless camera uses X-rays to view nanoscale materials and biological specimens
7. 4 Stanford faculty named Howard Hughes Medical Institute Investigators
8. Engineer to spearhead research into cell metabolism and medical injuries
9. UMass Medical Schools Craig Mello elected to American Academy of Arts and Sciences
10. American College of Medical Genetics makes genetic testing recommendations in new policy statement
11. Medical College researchers find dinosaur clues in fat
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/31/2016)... Florida , March 31, 2016 ... ) ("LegacyXChange" or the "Company") LegacyXChange ... potential users of its soon to be launched online ... ( https://www.youtube.com/channel/UCyTLBzmZogV1y2D6bDkBX5g ) will also provide potential ... use of DNA technology to an industry that is ...
(Date:3/23/2016)... , March 23, 2016 ... Interesse erhöhter Sicherheit Gesichts- und Stimmerkennung mit ... Inc. (NASDAQ: MESG ), ein ... dass das Unternehmen mit SpeechPro zusammenarbeitet, um ... der Finanzdienstleistungsbranche, wird die Möglichkeit angeboten, im ...
(Date:3/21/2016)... WAKEFIELD, Massachusetts , March 22, 2016 ... and facial recognition with passcodes for superior security ... MESG ), a leading provider of secure digital communications ... pilot their biometric technology and offer enterprise customers, particularly ... provide secure facial recognition and voice authentication within a ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... ... 2016 , ... Mosio, a leader in clinical research patient ... and Retention Tips.” Partnering with experienced clinical research professionals, Mosio revisits the hurdle ... and strategies for clinical researchers. , “The landscape of how patients receive and ...
(Date:6/23/2016)... , June 23, 2016   Boston ... of novel compounds designed to target cancer stemness ... has been granted Orphan Drug Designation from the ... treatment of gastric cancer, including gastroesophageal junction (GEJ) ... inhibitor designed to inhibit cancer stemness pathways by ...
(Date:6/23/2016)... 23, 2016 A person commits a crime, and ... to track the criminal down. An outbreak of ... Drug Administration (FDA) uses DNA evidence to track down the ... Sound far-fetched? It,s not. The FDA has increasingly used a ... of foodborne illnesses. Put as simply as possible, whole genome ...
(Date:6/23/2016)... ... June 23, 2016 , ... Charm Sciences, Inc. is ... has received AOAC Research Institute approval 061601. , “This is another AOAC-RI approval ... Bob Salter, Vice President of Regulatory and Industrial Affairs. “The Peel Plate methods ...
Breaking Biology Technology: