FMCW distance measurement process
First Claim
1. A FMCW distance measurement method, comprising:
- modulating a wave train of carrier frequency f0 by a time function f(t) and splitting said wave train into a transmission signal and a reference signal in a deterministic phase relationship;
putting the transmission signal onto a transmission link to be measured and feeding the reference signal to a phase difference-forming arrangement;
feeding a signal reflected in the transmission link and delayed by the propagation time τ
as a reception signal to the phase difference-forming arrangement;
wherein the phase difference-forming arrangement forms the time difference function θ
(t) of the phases between the reference and reception signals;
evaluating the phase difference function θ
(t) separately with respect to a direct component θ
= =g'"'"'(τ
, f0) assigned to the carrier frequency f0 and with respect to an alternating component θ
- (t)=g"(τ
, f- (t)) assigned to the modulation time function f(t); and
determining the propagation time τ
proportional to the distance by a combined evaluation of said direct component and said alternating component of the phase difference function.
0 Assignments
0 Petitions
Accused Products
Abstract
In an FMCW distance measurement process, a wave train of carrier frequency f0 is modulated with a time function f(t) and subdivided into a transmission signal and into a reference signal in deterministic phase relationship with the transmission signal; the transmission signal is sent on a transmission section to be measured and the reference signal is supplied to a phase difference-forming arrangement; the signal reflected in the transmission section with a delay that corresponds to propagation time τ is also supplied as a reception signal to the phase difference-forming arrangement that forms the time difference function θ(t) between the phases of reference and reception signals; the phase difference function θ(t) is separately evaluated in a continuous fraction θ= that corresponds to the carrier frequency f0 and in an alternating fraction θ- (t) that corresponds to the modulation time function f(t); and the propagation time τ proportional to the distance is finally determined by evaluating together both phase difference information.
-
Citations
11 Claims
-
1. A FMCW distance measurement method, comprising:
-
modulating a wave train of carrier frequency f0 by a time function f(t) and splitting said wave train into a transmission signal and a reference signal in a deterministic phase relationship; putting the transmission signal onto a transmission link to be measured and feeding the reference signal to a phase difference-forming arrangement; feeding a signal reflected in the transmission link and delayed by the propagation time τ
as a reception signal to the phase difference-forming arrangement;wherein the phase difference-forming arrangement forms the time difference function θ
(t) of the phases between the reference and reception signals;evaluating the phase difference function θ
(t) separately with respect to a direct component θ
= =g'"'"'(τ
, f0) assigned to the carrier frequency f0 and with respect to an alternating component θ
- (t)=g"(τ
, f- (t)) assigned to the modulation time function f(t); anddetermining the propagation time τ
proportional to the distance by a combined evaluation of said direct component and said alternating component of the phase difference function. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A FMCW distance measurement apparatus, comprising:
-
a transmitter coupled to a modulator, said transmitter generating a modulated wave-form; a receiver to receive a portion of said modulated waveform that is reflected off a target; a quadrature receiver to receive a reception signal corresponding to an electrical representation of said reflected portion of said modulated waveform and a reference signal corresponding to said transmitted modulated waveform, wherein said quadrature receiver generates a complex phasor having a time phase function corresponding to a phase difference function θ
(t) between said reference signal and said reception signal; anda processor coupled to said quadrature receiver to evaluate said phase difference function θ
(t) separately with respect to a direct component θ
= =g'"'"'(τ
, f0) assigned to a carrier frequency f0 and with respect to an alternating component θ
- (t)=g"(τ
, f- (t)) assigned to a modulation time function f(t) and to determine a propagation time τ
proportional to the distance to said target by a combined evaluation said direct component and said alternating component of the phase difference function. - View Dependent Claims (8, 9, 10, 11)
-
Specification