Featured Research

from universities, journals, and other organizations

Vibrating micro plates bring order to overcrowded radio spectrum

Date:
October 30, 2013
Source:
University of Twente
Summary:
GSM, WiFi, Bluetooth, 4G, GPS: a smartphone already has to handle many wireless standards. And this number will only increase further. There are still no good filters to keep all those future standards separate. Researchers have now taken an important step with a new type of filter, based on micromechanics.

The two square rectangles in the center of this SEM picture are the two resonators.
Credit: Image courtesy of University of Twente

GSM, WiFi, Bluetooth, 4G, GPS: a smartphone already has to handle many wireless standards. And this number will only increase further. There are still no good filters to keep all those future standards separate. Researchers at the MESA+ Institute for Nanotechnology have taken an important step with a new type of filter, based on micromechanics. They have published their finding in Applied Physics Letters.

Filters that can be accurately tuned to the frequency band you want to receive as a user are becoming increasingly important. Otherwise, if a nearby signal is much stronger, it drowns out the signal you want to receive. The number of available frequencies is limited, so it is becoming ever busier. Intelligent use of the airwaves, by utilising every available piece, is becoming more important. The filters now presented by the researchers are based on micromechanical resonators and can be accurately tuned to the desired frequency.

One of the reasons for choosing a mechanical solution is that the conventional filter consists of an inductor and a capacitor, an 'LC circuit'. Especially a good quality inductor is hard to achieve on a chip. The result would be: separate LC circuits for each frequency band, mounted outside the chip, which would take up too much space. New solutions are already being sought all over the world. The current standard is the electromechanical filter called Surface Acoustic Wave filter, but this, too, requires too much space if you need several of them.

Vibration

The solution presented by the researchers consists of two mechanical resonators. They vibrate at an adjustable frequency thanks to the piezoelectric material PZT. This material is applied to metal. Normally, the piezoelectric material vibrates perpendicular to the metal and the thickness of the layer determines the frequency. However,the frequency can be varied by making it vibrate in the same direction as the metal. Two resonators are used, which are not connected mechanically or electrically. By means of the intelligent handling of the input and output signals of the two resonators, adverse 'parasitic' effects are negated. This is done by subtracting the output signals, while the input signals are 'in phase'. The result is a selective filter -- fourth order -- that passes a limited part of the band and weakens the frequencies above and below. It can be accurately tuned with the vibrating frequencies of the two resonators. The filter presented by the researchers in Applied Physics Letters, operates at about 400 Megahertz. That is still too low for mobile applications, but new versions already reach higher frequencies, and Gigahertz frequencies needed for smartphones are feasible, according to the researchers.

The researchers also expect that these resonators can be integrated on the chip or directly 'bonded' to the chip: they are much smaller than inductors. It therefore becomes possible to apply fifty resonator pairs, which facilitates flexible use of frequencies. This is needed, for example, in 'cognitive radio', that uses each piece of free space as it becomes available and then jumps to another frequency when needed.

The research was conducted by the Transducers Science and Technology Group of the University of Twente MESA+ Institute for Nanotechnology in collaboration with the CTIT Institute Integrated Circuit Design group. There was also cooperation with the spinoff company SolMateS, which is specialised in making piezoelectric layers on chips. The project is financed by Dutch Technology Foundation STW.


Story Source:

The above story is based on materials provided by University of Twente. Note: Materials may be edited for content and length.


Journal Reference:

  1. Hadi Yagubizade, Milad Darvishi, Miko C. Elwenspoek, Niels R. Tas. A 4th-order band-pass filter using differential readout of two in-phase actuated contour-mode resonators. Applied Physics Letters, 2013; 103 (17): 173517 DOI: 10.1063/1.4826944

Cite This Page:

University of Twente. "Vibrating micro plates bring order to overcrowded radio spectrum." ScienceDaily. ScienceDaily, 30 October 2013. <www.sciencedaily.com/releases/2013/10/131030093041.htm>.
University of Twente. (2013, October 30). Vibrating micro plates bring order to overcrowded radio spectrum. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/2013/10/131030093041.htm
University of Twente. "Vibrating micro plates bring order to overcrowded radio spectrum." ScienceDaily. www.sciencedaily.com/releases/2013/10/131030093041.htm (accessed August 1, 2014).

Share This




More Matter & Energy News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Tesla, Panasonic Ink Deal To Make Huge Battery 'Gigafactory'

Tesla, Panasonic Ink Deal To Make Huge Battery 'Gigafactory'

Newsy (July 31, 2014) The deal will help build a massive battery factory that Tesla says will produce 500,000 lithium batteries by 2020. Video provided by Newsy
Powered by NewsLook.com
Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
7 Ways to Use Toothpaste: Howdini Hacks

7 Ways to Use Toothpaste: Howdini Hacks

Howdini (July 30, 2014) Fresh breath and clean teeth are great, but have you ever thought, "my toothpaste could be doing more". Well, it can! Lots of things! Howdini has 7 new uses for this household staple. Video provided by Howdini
Powered by NewsLook.com
Smoked: 2015 Ducati Diavel Vs 2014 Chevy Corvette Stingray Drag Race

Smoked: 2015 Ducati Diavel Vs 2014 Chevy Corvette Stingray Drag Race

Cycle World (July 30, 2014) The Bonnier Motorcycle Group presents Smoked; a three part video series. In this episode the 2015 Ducati Diavel takes on the 2014 Chevy Corvette Stingray Video provided by Cycle World
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins