Portable radar system

Claim 2

A radar system to provide an operator with an indication of the distance of remote objects comprising: means for generating a triangle wave; means for transmitting a radar signal and for receiving reflections of said transmitted signal from a remote object; means for FM-CW modulating said radar signal with said triangle wave; means responsive to said transmitted and received radar signals for deriving signals at frequencies representative of the difference between the frequency of the transmitted and received signals; means for providing as the period of said triangle wave a period which is long in relation to the duration of switching transients in said derived signal produced by slope reversals in said triangle wave; means for developing a signal variable over a range of frequencies substantially coextensive with the range of said derived signals; means for allowing said operator to acoustically monitor said derived signals and said developed signals; and control means for adjusting the frequency of said developed signal whereby said operator can adjust the frequency of said developed signal as monitored to appear as the average frequency of said derived signal and whereby the setting of said control means provides an indication of the distance of said remote object.

Claim 3

The system of claim 1 wherein the period of said triangle wave is long relative to the period of audible sound.

Claim 4

The radar system of claim 1 wherein said means for generating a triangle wave further includes: means for generating a square wave; and a single stage of electronic amplification receiving said square wave at a control input thereof and having negative resistive and capacitive feedback to said control terminal from a terminal of amplified response to the signal on said control terminal; said triangle wave being produced at said terminal of amplified response.

Claim 5

The radar system of claim 1 further including a source of regulated power for operating said radar system, said source comprising: a portable power source providing operating potential which diminishes with source use; an active element providing controlled conduction between first and second terminals thereof in response to a signal on a third terminal thereof and having said first terminal connected to a terminal of said portable source; a DC to AC converter receiving as an input the signal at said second terminal of said active element and providing as an output an AC signal having a peak magnitude substantially higher than the signal level from said portable source; means for developing a DC signal substantially equal to the peak output of said DC to AC converter; means for regulating said developed DC signal at a regulated, lower signal level and for applying said regulated signal level to the control terminal of said active element; and means for conducting a signal from said portable source to said means for regulating said developed DC signal whenever said developed DC signal is at a level less than the level of said portable source; the second terminal of said active element providing regulated power for the operation of said radar system independent of the past use of said portable source.

Claim 6

The radar system of claim 1 further including means for selectively enabling said monitor means during one slope of the triangle wave output of said generating means.

Claim 7

A radar system for providing an indication of the distance of remote objects comprising: means for generating a triangle wave having positive and negative slopes; means for transmitting radar signals and for receiving reflections of said radar signals from said remote objects; said transmitted radar signals having the frequency thereof varied with the level of said triangle wave; means for developing a signal having a frequency representative of the instantaneous frequency difference between said transmitted and received radar signals; means for providing as the period of said triangle wave a period which is of substantial duration relative to the duration of switching transients in said developed signal resulting from slope reversals in said triangle wave; means for amplitude limiting said signal developed at said difference frequency; means for high-pass filtering said amplitude limited signal; means for rectifying said high-pass filtered signal to produce a first train of pulses at a rate representative of said instantaneous frequency difference; and means for indicating the average number of said pulses in said first train of pulses during one or more whole cycles of said triangle wave to provide an indication of the relative distance of said remote objects.

Claim 8

A radar system for providing an indication of the distance of remote objects comprising: means for generating a triangle wave having positive and negative slopes; means for transmitting radar signals and for receiving reflections of said radar signals from said remote objects; said transmitted radar signals having the frequency thereof varied with the level of said triangle wave; means for developing a signal having a frequency representative of the instantaneous frequency difference between said transmitted and received radar signals; means for providing as the period of said triangle wave a period which is of substantial duration relative to the duration of switching transients in said developed signal resulting from slope reversals in said triangle wave; means for amplitude limiting said signal developed at said difference frequency; means for high-pass filtering said amplitude limited signal; means for rectifying said high-pass filtered signal to produce a first train of pulses at a rate representative of said instantaneous frequency difference; and means for indicating the average number of said pulses in said first train of pulses during one or more whole cycles of said triangle wave to provide an indication of the relative distance of said remote objects.

Claim 9

The radar system of claim 6 wherein said means for generating a triangle wave comprises: means for producing a signal which has high and low saturation levels and which periodically switches from one saturation level to the other with an interval between switching of one half the period of said triangle wave; an active element having first and second terminals of controlled conduction therebetween and a control terminal operative in response to said signal with high and low saturation levels to control conduction between said terminals of controlled conduction; and a path of negative resistive and capacitive feedback from one of said first and second terminals to said control terminal; said triangle wave being produced at one of said first and second terminals.

Claim 10

The radar system of claim 7 further including a source of regulated power for operating said radar system, said source comprising: a portable power source providing operating potential which diminishes with source use; an active element providing controlled conduction between first and second terminals thereof in response to a signal on a third terminal thereof and having said first terminal connected to a terminal of said portable source; a DC to AC converter receiving as an input the signal at said second terminal of said active element and providing as an output an AC signal having a peak magnitude substantially higher than the signal level from said portable source; means for developing a DC signal substantially equal to the peak output of said DC to AC converter; means for regulating said developed DC signal at a regulated, lower signal level and for applying said regulated signal level to the control terminal of said active element; and means for conducting a signal from said portable source to said means for regulating said developed DC signal whenever said developed DC signal is at a level less than the level of said portable source; the second terminal of said active element providing regulated power for operation of said radar system.

Claim 11

The radar system of claim 6 further including a source of regulated power for operating said radar system, said source comprising: a portable power source providIng operating potential which diminishes with source use; an active element providing controlled conduction between first and second terminals thereof in response to a signal on a third terminal thereof and having said first terminal connected to a terminal of said portable source; a DC to AC converter receiving as an input the signal at said second terminal of said active element and providing as an output an AC signal having a peak magnitude substantially higher than the signal level from said portable source; means for developing a DC signal substantially equal to the peak output of said DC to AC converter; means for regulating said developed DC signal at a regulated, lower signal level and for applying said regulated signal level to the control terminal of said active element; and means for conducting a signal from said portable source to said means for regulating said developed DC signal whenever said developed DC signal is at a level less than the level of said portable source; the second terminal of said active element providing regulated power for the operation of said radar system.

Claim 12

The radar system of claim 6 further comprising: means for developing a second train of pulses representative of said instantaneous frequency difference during one of said slopes of said triangle wave; and means for comparing the average number of said pulses in said first train with the average number of said pulses in said second train to provide an indication of the relative velocity of said remote objects.

Claim 13

The radar system of claim 6 further including means for providing acoustical monitoring of said developed signal.

Claim 14

A radar system for providing an operator with an indication of the distance of remote objects comprising: means for producing a fixed repetition rate slightly nonlinear sweep signal; means for transmitting radar signals and for receiving reflections of said radar signals from said remote objects; the frequency of said transmitted radar signals being controlled in response to the level of said sweep signal to provide a transmitted signal frequency varying nonlinearly with time; means for developing signals at frequencies representative of the instantaneous difference in frequency between said transmitted and received radar signals; means for generating signals at frequencies within a range of selectable frequencies substantially coextensive with the expected range of said difference frequencies; means for manually adjusting the frequency of said generating means within said range of selectable frequencies, said adjusting means providing an indication of its setting; adjustable means operative with said generating means for automatically varying the frequency of said generated signals in response to the level of said sweep signal; and means for permitting said operator to compare the frequency of said developed signals with the frequency of said generated signals whereby the frequency of the signal from said generating means may be adjusted for minimum apparent variation from the frequency of said developed signals and whereby the indicated adjustment of the frequency of said generating means provides an indication of the distance of said remote objects; said adjustable means for automatically varying the frequency of said generated signals further including means operative to provide a variation in the frequency of said generated signals which may be adjusted to substantially match the variation of said developed signals attributable to the nonlinearities in the variation of the frequency of said transmitted radar signals with time.

Claim 15

A radar system for providing an operator with an indication of the distance of remote objects comprising: means for producing a fixed repetition rate slightly nonlinear sweep signal; means for transmitting radar signals and for receiving reflections of said radar signals from said remote objects; the frequency of said transmitted radar signals being controlled in response to the level of said sweep signal to provide a transmitted signal frequency varying nonlinearly with time; means for developing signals at frequencies representative of the instantaneous difference in frequency between said transmitted and received radar signals; means for generating signals at frequencies within a range of selectable frequencies substantially coextensive with the expected range of said difference frequencies; means for manually adjusting the frequency of said generating means within said range of selectable frequencies, said adjusting means providing an indication of its setting; adjustable means operative with said generating means for automatically varying the frequency of said generated signals in response to the level of said sweep signal; and means for permitting said operator to compare the frequency of said developed signals with the frequency of said generated signals whereby the frequency of the signal from said generating means may be adjusted for minimum apparent variation from the frequency of said developed signals and whereby the indicated adjustment of the frequency of said generating means provides an indication of the distance of said remote objects; said adjustable means for automatically varying the frequency of said generated signals further including means operative to provide a variation in the frequency of said generated signals which may be adjusted to substantially match the variation of said developed signals attributable to the nonlinearities in the variation of the frequency of said transmitted radar signals with time.

Claim 16

The radar system of claim 12 further comprising means for permitting said operator to compare the frequency of said developed signals with the frequency of said generated signals during selected portions of a single slope of said sweep signal whereby said operator obtains an indication of the relative velocity of saId remote object.