Tag Archives: rf

Undetectable, Unjammable, and Interference-Free Ultra Wideband Radar System

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Summary:

Researchers at the Ohio State University have developed a virtually undetectable ultra wide band radar system that transmits pseudo random noise. On receive, the radar system cross-correlates a copy (possibly modified) of the original waveform with the receive signals. If a target reflects the signal (with modifications) then the radar will detect the reflection, the time delay, and Doppler. Thus the radar can tell the distance to a reflecting object and its relative speed. This is done using a waveform that will not interfere with other users of the spectrum. The noise waveform is extremely hard to detect. Researchers have further developed a system of storing the waveforms and performing the cross correlation at a particular time delay using a single memory device and no delay devices. This lends to the creation of a small, low cost, low power, stealthy radar that cannot be easily detected by conventional radar detection equipment and can be used for very short range applications. The radar can also be used to identify radar targets by using a pair of waveforms matched to the target radar impulse response. Thus the radar can also be used to detect only specific types of targets, as maybe required by the application.

Potential Applications:

  • Speed radar gun manufacturers seeking an undetectable radar gun
  • Simple moving vehicle/person/object with identification potential (automotive lane change warning)
  • Highway management to evaluate strength of material, or helicopter air to air warning systems
  • Low cost ground penetration radar for pipes, land mine detection, or probing human bodies
  • Low cost building penetration radar (security systems at casinos and airports)
  • Cross section instrumentation radar with inverse synthetic aperture imaging radar ability
  • Moving Radar, synthetic aperture radar systems

Advantages:

  • Robust with reference to interference or jamming – thus undetectable and hard to intercept
  • Unlikely to interfere with other noise radar systems or other radar systems in the same band
  • Low cost, small, light weight, and can be used for very short-range applications
  • Can be trained to be target specific (with the ability to specify multiple targets)
  • Would require no license to operate in civilian bands, and is fully coherent in amplitude and phase

Independently Fed AM/FM Heated Window Antenna

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Summary:

Dr. Eric Walton of the ElectroScience Laboratory at The Ohio State University has developed an automotive antenna that is effectively incorporated into the resistive, conductive heating elements found in automotive windows. The automobile industry has long recognized the advantages of forming an antenna in a vehicle window by imbedding conductors in the window glass. Manufacturers have also recognized that such windows can be defogged or defrosted by distributing resistive conductors over a major portion of the window area (the familiar heater grid found on the rear window of automobiles). It has been realized that the same conductors may be used for both heating the window area and as the communications antenna. The challenge lies in that the heater power source must be isolated from radio frequency signals in order to prevent RF currents from being shorted through the vehicle or heater power system. Previous attempts at isolation have been successful but have resulted in the need for heavy, expensive components and the need for separate antennas for different frequency bands. Dr. Walton’s design allows for optimal AM/FM reception (or the reception of other relatively low and high frequency bands found in modern wireless communication) and impedance matching using a single antenna, whereas previous designs required the use of two separate, different antennas. The design further allows for an apparatus with reduced size, weight, and cost as compared to previous methods. When coupled with U.S. Patents #6,320,558 and #6,483,468 (On-Glass Impedance Matching Antenna Connector, Reference #99062), impedance matching in the AM and FM bands can be easily achieved and a complete on-glass automotive AM/FM antenna/heater grid configuration realized.

Potential Applications:

  • A sleek, lightweight, and low-cost antenna solution that is integrated into existing heater grid configurations
  • When coupled with U.S. Patents #6,320,558 and #6,483,468 (On-Glass Impedance Matching Antenna Connector, Reference #99062), impedance matching in the AM and FM bands can be easily achieved and a complete on-glass automotive AM/FM antenna/heater grid configuration realized

Advantages:

  • Effectively incorporates an antenna into a vehicle’s heater grid system
  • Allows for the reception of multiple bands with large frequency separation
  • Provides a smaller, lighter, lower-cost alternative to previous methods

Novel Design For High-Gain Antennas Integrated into the Heater Grid on Autoglass

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Summary:

Researchers at the ElectroScience Laboratory at The Ohio State University, in cooperation with an Italian automotive antenna manufacturer, have developed an improved wire pattern layout for an automotive window antenna. Automobiles traditionally have heating elements printed on the rear window for defrosting/defogging purposes, and such elements usually cover the majority of the window in order to defrost the entire area. This leaves little room for an isolated RF antenna on the window, and as a result the smaller antenna geometry results in relatively poor performance. This invention alleviates this problem by incorporating the RF antenna into the heater grid configuration, while taking into account the effects of the heater grid pattern and the general characteristics of RF current throughout the circuit. The result is a rear window antenna with improved performance that is seamlessly and attractively integrated into the already existing heater grid configuration.

Potential Applications:

  • An attractive and low cost alternative to traditional automotive antennas
  • Heater grid pattern and antenna wire pattern can be deposited on glass together, saving substantial cost and expediting the manufacturing process

Advantages:

  • Enhanced directional gain and impedance characteristics over other window antenna designs
  • Easy to integrate into existing automotive rear window heater element configurations

RF-Transmitting, IR-Blocking Metallic Panel for Windows/Autoglass

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Summary:

Dr. Eric Walton of the ElectroScience Laboratory at The Ohio State University has developed a unique metallic panel aperture design that allows the transmission of radio waves through the panel while blocking infrared radiation. Optically transparent metal panels are often used in automotive or building windows where heating and/or the reflection of infrared radiation is desired. It has been shown that a thin, transparent metallic layer can be deposited on one of the layers of a multi-layer automotive windshield and used for heating/deicing/defogging when powered using bus bars on the top and bottom of the windshield. However, a uniform metallic coating prevents the transmission of radio signals, which is unacceptable given the widespread use of cell phones, GPS receivers, and other electronics commonly used in automobiles and buildings. This invention alleviates these problems; permitting uniform heat distribution and simultaneously allowing the passage of radio waves. The invention is useful in any application where a metallic panel is used to heat a material or to reflect infrared radiation, and where heat uniformity and radio transmission is important.

Potential Applications:

  • Heated windshields are currently an option on a limited number of vehicles, but will eventually become standard equipment. An autoglass maker would do well to adopt this technology quickly
  • The blocking of infrared radiation means a cooler vehicle or building interior on hot summer days
  • Can be used to heat building windows in cold climates or block infrared radiation in warmer ones, improving energy efficiency

Advantages:

  • Simple design that is easy to replicate
  • Provides uniform heat over the metallic panel
  • Allows RF transmission while blocking IR