Pulse radar ranging system
View Patent ↗A pulse radar ranging system having a measurement channel and a reference channel is described. In the measurement channel containing an antenna and a measurement target, the normal measurement is performed by processing an echo from the target. In the reference channel containing signal delay means, a reference echo is processed to obtain temperature compensation information.
1. A pulse radar ranging system, comprising:
transmit pulse generator means for generating transmit pulses at a transmit clock frequency;
sampling pulse generator means for generating sampling pulses at a sampling clock frequency slightly different from the transmit clock frequency;
a first signal mixer having a first signal input and a second signal input, the first signal input being coupled to the sampling pulse generator means;
a second signal mixer having a first signal input and a second signal input;
directional coupling means having a first port coupled to the transmit pulse generator means, a second port coupled to an antenna, a third port coupled to the second signal input of the first signal mixer, and a fourth port;
signal processing means;
splitting means arranged between the sampling pulse generator means and the respective first signal inputs of the first and second signal mixers to divide the sampling pulses into first sampling pulse portions conveyed to the first signal mixer and second sampling pulse portions conveyed to the second signal mixer; and
signal delay means arranged between the fourth port of the directional coupling means and the second signal input of the second signal mixer.
2. The pulse radar ranging system as claimed in claim 1 , wherein the directional coupling means convey transmit pulses to be transmitted via the antenna to a target and to convey echo pulses reflected from the target and received by the antenna to the second signal input of the first signal mixer.
3. The pulse radar ranging system as claimed in claim 2 , wherein the first signal mixer generates a first intermediate frequency signal by mixing the echo pulses with the sampling pulses.
4. The pulse radar ranging system as claimed in claim 3 , wherein the signal processing means evaluate the first intermediate frequency signal to determine the target distance.
5. The pulse radar ranging system as claimed in claim 4 , wherein the directional coupling means divide the transmit pulses received at the first port into first transmit pulse portions directed to the second port and second transmit pulse portions directed to the fourth port.
6. The pulse radar ranging system as claimed in claim 5 , wherein the second signal mixer generates a second intermediate frequency signal by mixing the second transmit pulse portions with said second sampling pulse portions.
7. The pulse radar ranging system as claimed in claim 6 , wherein the signal processing means further evaluates the second intermediate frequency signal for correcting the determination of the target distance.
8. The pulse radar ranging system as claimed in claim 1 , wherein the signal delay means have a delay line.