Small, low-noise oscillator may help in surveillance

Sep 16, 2006

A new design for a microwave oscillator that is smaller, simpler, and produces clearer signals at a single frequency than comparable devices has been invented at the National Institute of Standards and Technology (NIST).

Applications could include homeland security (e.g., surveillance of radio traffic for anomalous signals, or high-resolution digital imaging radar on unmanned aircraft), telecommunications (e.g., maintaining separation between frequencies in high-bandwidth networks), and perhaps even consumer devices (e.g., satellite television downlinks).

A patent was issued recently* for the NIST oscillator, which is about the size of a roll of 35 mm camera film. NIST researchers have built five prototypes on test fixtures, which offer several-orders-of-magnitude reductions in various types of self-generated signal interference, or noise, compared to typical commercial oscillators, resulting in improved frequency stability, according to David Howe, one of the inventors. In addition, the simple design reduces costs and improves reliability, while consuming less power than other oscillators of comparable signal purity. The small size could be an advantage on some surveillance platforms.

Microwave oscillators are used as reference or clock signals in many high-precision technologies. Through control of temperature and other variables, the oscillators produce a desired signal at one narrowly defined frequency while suppressing random, electronically induced "noise" generated by components. In the best microwave oscillators, the signal typically is amplified inside a metal cavity containing a solid insulating material that internally sustains microwaves and radio waves with minimal loss, especially at cryogenic temperatures, an expensive and complex design. By contrast, the NIST oscillator uses an ultra-stiff ceramic manifold that supports a single frequency with either a vacuum or air as the insulating medium.

The NIST device operates at high signal power (many watts) without the noise penalty found in the conventional design just described. The technique maintains such a stable frequency that it can overcome or compensate for self-generated noise produced by components such as amplifiers that sustain oscillation. NIST researchers continue to work on improvements, hoping to make the technology more tolerant of vibrations such as those from aircraft, field radars, and even sub-audible vibrations in buildings.

Source: NIST

Explore further: Comfortable climate indoors with porous glass

add to favorites email to friend print save as pdf

Related Stories

'Comb on a chip' powers new atomic clock design

Jul 22, 2014

Researchers from the National Institute of Standards and Technology (NIST) and California Institute of Technology (Caltech) have demonstrated a new design for an atomic clock that is based on a chip-scale ...

Portable frequency comb rolls out of the lab

Mar 21, 2014

A PML team is hitting the road with a fine-tooth comb. Scientists in the Quantum Electronics and Photonics Division have devised a portable optical frequency comb that is capable of laboratory-grade measurements ...

A new era for atomic clocks

Feb 05, 2014

A revolution is under way in timekeeping. Precision timekeeping based on atomic clocks already underpins much of our modern technology—telecommunications, computer networks and satellite-based positioning ...

Photon recoil provides new insight into matter

Jan 30, 2014

Quantum logic spectroscopy – which is closely linked with the name of the 2012 Nobel prize laureate, David J. Wineland – has been significantly extended: this new method is called "photon-recoil spectroscopy" ...

Recommended for you

Comfortable climate indoors with porous glass

14 hours ago

Proper humidity and temperature play a key role in indoor climate. In the future, establishing a comfortable indoor environment may rely on porous glass incorporated into plaster, as this regulates moisture ...

Crash-testing rivets

14 hours ago

Rivets have to reliably hold the chassis of an automobile together – even if there is a crash. Previously, it was difficult to predict with great precision how much load they could tolerate. A more advanced ...

Customized surface inspection

14 hours ago

The quality control of component surfaces is a complex undertaking. Researchers have engineered a high-precision modular inspection system that can be adapted on a customer-specific basis and integrated into ...

Sensors that improve rail transport safety

14 hours ago

A new kind of human-machine communication is to make it possible to detect damage to rail vehicles before it's too late and service trains only when they need it – all thanks to a cloud-supported, wireless ...

Tiny UAVs and hummingbirds are put to test

Jul 30, 2014

Hummingbirds in nature exhibit expert engineering skills, the only birds capable of sustained hovering. A team from the US, British Columbia, and the Netherlands have completed tests to learn more about the ...

User comments : 0