摘要:
An improved self-powered vehicle detector (SPVD) uses a two-axis magnetomr to sense a vehicle's magnetic signature and then telemeter vehicle presence information to a roadside receiver. The SPVD system includes digital nulling loops to cancel D.C. offset changes in the magnetometic output, a multi-tone code transmitter to transmit vehicle presence and SPVD condition signal, and an omnidirectional microstrip antenna to simplify installation and maintenance of the SPVD.
摘要:
A microstrip board comprising a gold film which contains about at least 1/2 weight per cent of aluminum bonded to a non-electrical conducting oxide is prepared by simultaneously evaporating the gold and aluminum onto the non-electrical conducting oxide and thereafter optionally heating the film thus formed.
摘要:
An electrically short, omnidirectional antenna formed with a strip conduc helically wound about the outside of a cylindrical ground plane. A layer (ideally, a very thick layer) of a nonconducting material preferably with a low dielectrical constant (i.e., .epsilon..sub.r .perspectiveto.1.0) separates the microstrip from the ground plane.
摘要:
A conformal electronically scanned antenna array system utilizing an inve Butler matrix in combination with directive antenna elements. The system provides a simple and inexpensive device for scanning an elemental array without the problems of output frequency shift or mutual coupling between antenna elements.
摘要:
A compact, directional antenna element for achieving narrow beamwidths andide bandwidths. The element is formed from a polyrod having a high dielectric constant embedded in a wave guide made of a second medium having a dielectric constant slightly lower than that of the rod.
摘要:
A modified Huggin's Scanner whose tunable signal bandwidth can be broadenedithout affecting the beam position and whose output beam direction is dependent on the control of a resistor. Two separate voltage controlled oscillators are utilized in this system in addition to modifying the input frequency controls to the scanner.
摘要:
A millimeter wavelength solid dielectric waveguide having either an undulng or roughened outer surface is disclosed. As configured, and properly designed, for the wavelength of interest, the non-cylindrical surface will not have any deleterious effects on the electromagnetic properties of the dielectric waveguide. Moreover, the novel surface treatment will greatly increase the amount of heat energy that can be dissipated by radiation and convection from the dielectric waveguide thereby increasing its power handling capability.
摘要:
A detector for non-destructive sensing of binary information at a selected location along a domain wall of a thin magnetic film strip. Voltages are applied across a set of contacts arranged along the margin of the strip and the value of the voltage measured at an arranged, centered contact indicates the presence or absence of a Bloch line-crosstie pair at that location.
摘要:
An electric wave operating device for efficiently coupling electromagnetic energy from a waveguide into a dielectric element or vice versa. A waveguide horn portion is chosen for radiating in the primary HE.sub.11 mode and designed to have a predetermined HE.sub.11 mode farfield radiation pattern. A dielectric member is securely disposed with one end in the plane of the aperture of the waveguide horn with the dielectric member having a predetermined HE.sub.11 mode farfield radiation pattern substantially equal to the farfield radiation pattern of the horn.