US 6,091,355 A · Doppler radar speed measuring unit

Abstract

A Doppler radar speed measuring module, that is self-contained and handheld, is fabricated on a multilayer PCB (printed circuit board) containing at least one antenna array and electronic circuitry. In one embodiment the antenna array is located on a top side and electronic circuitry is located on a bottom side opposite the antenna, with a ground plane layer sandwiched between the antenna array and the circuitry. The electronic circuitry includes a dielectric resonator stabilized oscillator, a microwave amplifier, a microwave mixer, a microwave coupler, voltage regulators, mechanical switches, and a display to indicate the measured speed of a moving target. The oscillator generates a very stable microwave signal which is split with part of the signal fed to a mixer and part fed to a transmit antenna. In one embodiment plated through vias electrically connect the two sides together. A transmitted signal reflects off of a moving target and is received by a receive antenna. The receive signal is electrically conducted from the receive antenna to the opposite side by plated through vias and is mixed with the oscillator signal to produce a low frequency Doppler beat signal. The Doppler signal is amplified, filtered and digitized by the A/D. A microcontroller is programmed to determine the moving target speed from the Doppler signal frequency, and drive a display to show the result.

Claims23

Dependent claims

A portable ultracompact radar system for measuring the speed of a moving target by means of a Doppler shift, comprising:

a multilayer printed circuit board includes on a top portion a first outer electrically conductive layer onto which a transmit antenna and a receive antenna are patterned, and on a bottom portion a second outer electrically conductive layer formed into a plurality of electrically conductive paths, said second outer conductive layer being in a plane parallel to the plane of said first outer conductive layer, said first and second outer conductive layers having at least one ground plane layer disposed therebetween, each of said layers being electrically isolated from one another by an individual electrical insulation layer;
and
electronic circuitry mounted upon said electrically conductive paths of said second outer conditions layer, the circuitry comprising an oscillator for producing an output signal, said output signal being coupled to a first input of a coupler means for dividing said oscillator output signal into an rf output signal coupled to the transmit antenna, and a local oscillator signal coupled to a first input of a mixer means, the mixer means having a second input receptive of a target reflective signal from the receive antenna, said mixer means operating to combine said local oscillator signal and said target reflected signal to produce a Doppler signal, a microcontroller being receptive of said Doppler signal for processing the same and producing a speed signal for connection to and display by means for displaying the detected speed;
and
means for electrically interconnecting portions of said first and second outer layers and said at least one ground plane layer together.

2 more elements

A self-contained portable ultracompact radar system for measuring the speed of a moving target, comprising:

a multilayer printed circuit board including:
a center core of electrically insulative material;
first and second electrically conductive ground plane layers having inner surfaces secured to top and bottom sides of said center core, respectively;
first and second electrically insulative substrates having innermost sides secured to an outer surface of said first and second ground plane layers, respectively, said first and second electrically insulative substrates also having outermost sides parallel to and opposing there innermost sides, respectively;
transmit and receive antenna patterns formed from a layer of electrically conductive material secured to the outermost side of said first electrically insulative substrate;
electrically conductive paths formed from a layer of electrically conductive material secured to the outermost side of said second electrically insulative substrate;
means for selectively electrically interconnecting portions of said transmit and receive antenna patterns to portions of said electrically conductive paths;
electronic means mounted upon the outermost side of said second electrically insulative substrate, and electrically connected to preselected portions of said electrically conductive paths, for selectively applying an rf signal to said transmit antenna for transmitting into the path of a moving target, for thereafter receiving a target reflected signal from said receive antenna, said electronic means further including mean for processing a portion of said rf signal and said target reflected signal, for producing a speed signal for application to a display, for displaying the speed of said moving target on a display.

5 more elements

Dependencies are inferred from the claim text.

Doppler radar speed measuring unit

Life of this patent

Doppler radar speed measuring unit

Life of this patent

Abstract

Claims23