Navigation Links
How to make microwaves on a chip to replace X-rays for medical imaging and security

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
Cornell University Communications

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:
(Date:11/9/2015)... 2015  Synaptics Inc. (NASDAQ: SYNA ), the ... entry into the automotive market with a comprehensive and ... of consumer electronics human interface innovation. Synaptics, industry-leading touch ... the automotive industry and will be implemented in numerous ... , Japan , and ...
(Date:10/29/2015)... 29, 2015 Daon, a global leader in ... released a new version of its IdentityX Platform ... North America have already installed IdentityX v4.0 ... a FIDO UAF certified server component as ... activate FIDO features. These customers include some of the ...
(Date:10/27/2015)... , Oct. 27, 2015 In the ... issues of concern for various industry verticals such as ... due to the growing demand for secure & simplified ... various ,sectors, such as hacking of bank accounts, misuse ... electronic equipment such as PC,s, laptops, and smartphones are ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... , November 25, 2015 ... Research Report is a professional and in-depth study ...      (Logo: ) , ... of the industry including definitions, classifications, applications and ... provided for the international markets including development trends, ...
(Date:11/24/2015)... ... ... The United States Golf Association (USGA) today announced Dr. Bruce Clarke, of ... since 1961, the USGA Green Section Award recognizes an individual’s distinguished service to the ... of Iselin, N.J., is an extension specialist of turfgrass pathology in the department of ...
(Date:11/24/2015)... 2015 /CNW/ - iCo Therapeutics ("iCo" or "the Company") ... for the quarter ended September 30, 2015. Amounts, ... and presented under International Financial Reporting Standards ("IFRS"). ... said Andrew Rae , President & CEO ... not only value enriching for this clinical program, ...
(Date:11/24/2015)... /PRNewswire/ - Aeterna Zentaris Inc. (NASDAQ:  AEZS) (TSX: AEZ) (the ... the Toronto Stock Exchange, confirms that as of the ... developments that would cause the recent movements in the ... --> About Aeterna Zentaris Inc. ... Aeterna Zentaris is a specialty biopharmaceutical company engaged in ...
Breaking Biology Technology: